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Zoom Dinosaurs
DINOSAUR QUESTIONS
Current Questions Top 16 Questions Old Questions Ask A Question
For Site Supporters Only
By Date By Type of Dinosaur General Dino. Qns. Qns. About Other Animals Geological Era Qns.

General Questions about Dinosaurs 2


Q: Could there ever be a mummified dinosaur ever found , say maybe found under the snow in Antartica as there have been dinosaur remains found there?
from Ruth S., Glasgow, Ayrshire, Scotland; August 26, 1998

A: It's been too long for any animal tissue to survive, even in the driest conditions. Even the latest dinosaurs have been dead about 65 million years.

There is a type of fossil that is referred to as dinosaur "mummies", fossilized imprints of dinosaur skin and other features. These are not real mummies in which actual animal tissue is preserved, but fossilized imprints that look a bit like mummies.



Q: What is the name of dinosaurs that eat plants and meat?
from Sarah L., Warrnambool, Victoria, Australia; August 26, 1998

A: Any animal that eats both meat and plants is called an omnivore. People and birds are examples of omnivores.



Q: Is there more or less water on the planet or is there about the same as when the dinosaurs were here as my dad says. He says that all the water that will ever be on the planet was made back then and can't be made or destroyed.Is this true?
from Alain F., Orlando, FL, USA; August 24, 1998

A: This is quite a complicated and controversial scientific issue. There is a new theory that there are comets composed of frozen water that are constantly bombarding the Earth. These "cosmic snowballs" have been seen by the visible imaging system of the Polar Satellite. These frozen comets vaporize in the atmosphere, adding water vapor to the environment. There is an interesting web site on this theory at http://csep10.phys.utk.edu/astr161/lect/comets/smallcomets.html .

If this theory is true then there was less water on Earth during the Mesozoic Era, when the dinosaurs lived. The Earth, however, was warmer during the Mesozoic Era than it is now. There were no frozen polar ice caps on Earth during most of the Mesozoic and this extra available water flooded a lot of low-lying land, forming shallow seas. Most of North America was under water for a lot of the Mesozoic.



Q: Is it possible to clone dinosaurs from dino DNA, like in the movie Jurassic Park?
from Ira P., Hong Kong, China; August 22, 1998

A: It is not very likely that any DNA could survive for at least 65 million years without degrading - even if it were trapped in amber. This would make cloning a problem.



Q: If dinosaurs weren't extinct, will they attack humans like those in Jurassic Park?
from ?, Hong Kong, China; August 22, 1998

A: The large meat-eaters probably would, espcially if they were hungry, but the dinosaurs in Jurassic park were given more intelligence than the fossil evidence warrants and sometimes, a larger size (for example, fossil Velociraptors are about half the size of the ones in the movie).



Q: Besides their sizes and the places they lived, can you tell me the other differences between Velociraptor and Deinonychus?
from Ira P., Hong Kong, China; August 21, 1998

A: A major difference is when they lived. Deinonychus lived in the early Cretaceous period, about 110 to 100 million years ago (some estimate this range to be more like 99 - 93 mya); Velociraptor lived during the late Cretaceous period, about 85 - 80 mya.

Also, Velociraptor had a flatter snout than Deinonychus.



Q: Where can I found a complete and actualized list of dinosaurs ?
from Marc G., Clarens, Vaud, Switzerland; August 19, 1998

A: For a list a list of the major families of dinosaurs and many common genera, click here.



Q: What is a Bipedal?
from Campbell P, masterton, wairarapa, new zealand; August 18, 1998

A: Bipedal animals walk on two legs. Examples of bipedal animals include people, kangaroos, T. rex, Velociraptor, etc. (Bi means two and pedal means feet.)



Q: has anyone seen a living dinosaur ? how do scientists know that they once lived ? how many kind of dinosaurs were there?
from mukesh v, Durban, South Africa; August 17, 1998

A: No. dinosaurs went extinct millions of years before people existed - see the illustration below. Their fossilized bones are scatteread throughout the Earth. So far, about 600 dinosaurs species have been found, but there must have been many more.
Dinosaur timeline




Q: I'm interested in finding info about the newest dino. found I believe it was found in mexico.
from ??; August 16, 1998

A: The big news lately is the largest group of dinosaur trackways found in the Andes mountains in Bolivia, South America (near the town of Sucre). Although they were found in1996, they were just in the news a few days ago, and the analysis of the trackways has barey begun. There are hundreds of tracks that date from the late Cretaceous period, and include a lot of large sauropods, ankylosaurs, ceratopsians like Triceratops, and other as yet unidentified dinosaur. The tracks are up to 3 feet (1 m) long.

So far, the most surprising result is that the ankylosaurs were apparently travelling at a pretty fast rate, which is not what was expected, given their massive bodies, heavy armor covering, and stubby legs. Other ankylosaur trackways (there are only about a dozen worldwide, six of which are in this new find) show slow locomotion, but these Bolivian ankylosaurs were relatively speedy, as were the sauropods.

The Swiss paleontologist Christian Meyer, who has been working at the site for a few months, says, "There is no comparable site in the world." The site covers 25,000 square meters in a limestone quarry, and parts of the track are at angles up to 70° from horizontal. The tracks were made on an ancient lakebed that had been pushed up along with the Andes mountains. The trackways are 440 miles (700 km) south of La Paz, Bolivia and are at an altitude of 900 miles (2,800 meters). Other fossils have been found at the site, including crocodiles, fish, and turtles.



Q: What are the dinosaurs That lived in Saskatoon?
from Lyndon, Saskatoon, Saskatchewan, Canada; August 15, 1998

A: I don't know about Saskatoon in particular, but Edmontosaurus, Thescelosaurus, Torosaurus, Triceratops, and Tyrannosaurus coprolites have been found in Saskatchewan. For more Canadian fossils, see this page.



Q: Could meat-eating dinosaurs chew their food?
from ??; August 15, 1998

A: No, but different theropods (the meat eaters) had different types of teeth. Some had knife-like teeth (like Giganotosaurus) that just sliced off meat that was then swallowed whole. Others, like T. rex, had thick, conical teeth that could crush the food, bones and all. No theropods had molar-like teeth that would be needed for chewing.






Q: What is the difference between ornithichians and saurischians
from Chris H., Sydney, New South Wales, Australia; August 14, 1998

A: The main difference is the hip structure - in particular, which way the pubis bone points.

Q: Why did the big dinosaurs have such small brains?
from Michael K., Silver Lake, Ohio, USA; August 13, 1998

A: Good question. The large dinosaurs were essentially giant lawn mowers. They didn't have to do much in life but eat all day and occasionally reproduce. They were so large that predators weren't much of a problem, so a large brain wasn't necessary for survival. They lived for millions of years and probably died out when food sources (available plants) were depleted. A larger brain wouldn't have helped much in this respect.

Predators that have to hunt to eat need large brains in order to find and then catch prey. Large plant-eaters don't need that much brain power, they just graze on plants. Small plant-eaters need more brains in order to avoid predators.



Q: WHAT ARE THE BIGGEST DINOSAURS.
from JAMES P., PHILADELPHIA, PA, U.S.; August 13, 1998

A: The biggest dinosaurs were sauropods; they were gigantic, slow-moving, tiny-headed, cow-like plant-eaters from the late Jurassic and the Cretaceous period. They had very long necks which were useful for reaching wide (and tall) swatches of vegetation. The lengthy neck was counterbalanced by a massive tail. These sauropods are the largest land animals ever discovered:
  • Supersaurus - 134 feet long (41 m)
  • Argentinosaurus - 115-130 feet long (35-40 m); 80-100 metric tons
  • Seismosaurus ("Earth-shaking lizard") - 120+ feet long (37 m); +80 tons
  • Ultrasauros - 100+ feet long (30 m), +80 tons
  • Diplodocus - grew up to 90 feet long (28 m).
  • Brachiosaurus - about 85 feet long (26 m), 40 feet tall, and weighed 70-80 tons.



Q: How many dinosaur bones are there in the world and how big are some of the bones? What is the biggest dinosaur in the world? How many dinosaurs where there in the USA. What was the biggest raptor in the world? How much did the T-Rex weigh? How much did T-REX eat?
from Thomas D., Poughkeepsie, NY, USA; August 12, 1998

A: One of the largest dinosaur bones ever found was the shoulder blade of Supersaurus, a giant sauropod. It was over 6 feet tall and a couple of feet wide. It was found in1972 by James Jensen in western Colorado, USA. Huge sauropod femurs (leg bones) are also larger than people. I don't know how many bones have been found.

The biggest dinosaur is probably Seismosaurus, about 135 feet long. T. rex weighed about 5-7 tons. For more information on T. rex, click here.



Q: HOW DID WE COME TO KNOW ABOUT THE EXSISTENCE OF DINOSAURS AND IN WHICH YEAR DID THEY EXIST? WAS GODZILLA REALLY THAT TERIFYING AS SHOWN IN THE MOVIE?
from AARUSHI J., LUDHIANA, PUNJAB, INDIA; August 12, 1998

A: People first discovered dinosaur (Megalosaurus) bones in England in 1676. The term dinosaur was coined by the English anatomist Sir Richard Owen in 1842. He named large extinct reptile fossils dinosaurs, meaning "terrifying lizards" (in Greek, deinos means terrifying; sauros means lizard). The only three dinosaur fossils known at the time were Megalosaurus, Iguanodon, and Hylaeosaurus, very large dinosaurs.

Dinosaurs lived from about 225 to 65 million years ago. Godzilla is a fictional animal - it never existed.



Q: Which dinosaur was the : 1.Smallest ?
2.Biggest ?
3.Cleverest ?
4.Dumbest ?
5.Slowest ?
6.Fastest ?

from Dhruv S., New Delhi, Delhi, India; August 10, 1998

A: 1. Compsognathus,
2. Tallest is probably Ultrasauros,
longest is probably Supersaurus,
3. troodontids and dromaeosaurids (for example, Troodon),
4. Sauropodamorphas (for example, Massospondylus),
5. Perhaps the large ankylosaurs, like Ankylosaurus,
6. bird-like bipedal carnivores (theropods) like Gallimimus.

For more information on extreme dinosaurs, click here.



Q: What kind of rock are most fossils found?
from Lyndon C., Saskatoon, Saskatchewan, Canada; August 9, 1998

A: Most fossils are excavated from sedimentary rock layers. Sedimentary rock is rock that has formed from sediment, like sand, mud, small pieces of rocks. Over long periods of time, these small pieces of debris are compressed (squeezed) as they are buried under more and more layers of sediment that piles up on top of it. Eventually, they are compressed into sedimentary rock. It is made of strata, or layers. The layers that are farther down in the Earth are older than the top layers.

For more information read the section on fossils or the glossary entry on sedimentary rock.



Q: who came up with the term 'dinosaurs'?
from noorreha s., Bukit panjang, Singapore; August 3, 1998

A: The term dinosaur (deinos means terrifying; sauros means lizard) was coined by the English anatomist Sir Richard Owen in 1842. The only three dinosaurs known at the time were Megalosaurus, Iguanodon, and Hylaeosaurus, very large dinosaurs.



Q: I read an article about 3-4 years ago that had as its premise "Birds came first" and that dinoaurs actually evolved from birds. Do you have any information on this theory? Thank you.
from Irene Q., West Palm Beach, FL, USA; August 3, 1998

A: The earliest known dinosaur (the Eoraptor) evolved during the mid-Triassic period, about 228 million years ago. The earliest known bird, the Archaeopteryx, evolved millions of years later, about 150 million years ago during the Jurassic period. This chronology makes the theory you heard about seem impossible.



Q: Is Godzilla truly a Dinosaur?
from Marc C., Rizal, Phillipines; July 31, 1998

A: Hello again, Marc. Godzilla is entirely fictional, but it looks as though it was designed with T. rex in mind.



Q: 1.3 characteristics of meat eating and plant eating dinosaurs. 2.Dinosaurs have how many teeths? 3..How do dinosaurs defend and protect themselves? 4.Which dinosaur is the fastest? 5.Give two reasons why dinosaurs live in groups? 6.Name two types of teeths that different types of dinosaurs might have? 7.Give two physical description and two examples of these animals?
from Siti Khatijah, Singapore; July 29, 1998

A: 1. There is a discussion of this in the section called "Diet" in "Anatomy and Behavior."
2. See the section called "Teeth" in "Anatomy and Behavior."
3. See "Offense" and "Defense," again in "Anatomy and Behavior."
4. For the fastest, see "Extreme Dinosaurs."
5. See the section "Herds/Packs" in "Anatomy and Behavior."
6. Same as the previous tooth question.
7. See the "Dinosaur information sheets."



Q: How many and where were the most dinosaur bones found?
from Jaime W., West Seneca, NY, USA; July 27, 1998

A: Click here for a listing of where individual dinosaur fossils have been found. Great concentrations of dinosaur fossils have been found in Montana, Colorado, Alberta, CA, and a few other locales world-wide, including Lioaning, China (where the recent discoveries of bird-like dinosaurs have been made).



Q: are some dinosaurs still alive?
from Austen S., Sierra Vista, Arizona, USA; July 25, 1998

A: Only if you count the birds. Technically, if the birds are descendants of the dinosaurs, then birds are included in the clade of dinosaurs, so birds are dinosaurs.



Q: Where are fossils usually found?
from Courtney. C, Launceston, Tasmania, Australia; July 23, 1998

A: Fossils are usually found in places where there is exposed sedimentary rock, for example bad lands. If you're looking for dinosaur fossils, the sedimentary rock must have formed during the Mesozoic Era, when the dinosaurs lived. Dating the rock layers can be done in many different ways, two of which are: by radio-isotope dating of the bracketing volcanic layers or by looking at index fossils in the sediment. (Index fossils are from rganisms that are common, well known and well distributed. The dates during which these organisms lived is well documented and either relatively short or having one end point known. For more information on index fossils, click here.)

Sedimentary rock is the type of rock that is formed from sediment, like sand, mud, and small rocks. This debris (along with any organisms) is compressed (squeezed) as more sediment piles on top of it.

For more information on sedimentary rocks, click here. For more information on fossils, click here. For a list of locations of fossils finds, click here.



Q: Do you know all the dinosors names if not or you do can you tell me some.
from Jeromy, newington, ct, USA; July 21, 1998

A: We know about 330 genera (groups) of the dinosaurs - there were a lot more than that that have yet to be found. I have a list of most of the dinosaurs and where they were found - click here to go to it. Also, there are information sheets for a lot of dinosaurs (with their pictures) - just click here.



Q: What do you think about how dinosaurs died. I think they died of a disease because during the peiroids of dinosaurs extinction was a common thing like the stegasaures started at the bigining of the jurasic peiriod and died at the end of the jurasic. what this has to do with diseases is dinosaurs with the disease died. This desease was also spreading. How did dinosaurs from all over the world get it well the plates of the world during the time were pulling a part but still together so dinosaurs could spread the disease all over contenets.
from David D., USA; July 19, 1998

A: Your theory is well thought out. One problem is the fact that it wasn't just the dinosaurs that went extinct 65 million years ago. Many other species died out, including plants, fish, marine organisms and members of every group of life forms. It is highly unlikely that they all could get the same disease. The Alvarez asteroid theory seems the most likely of all the theories I've read.



Q: what are two sauropod dinosaurs have been claimed to have been seen in africa this century? what giant creature has attacked people in the amazon basin?
from angela m., Centerville, OH, USA; July 13, 1998

A: There's an article on the supposed African sightings (which I think are pretty farfetched) here.



Q: where are the paleontologist universities in Australia?
from Andrew W., New South Wales, Australia; June 25, 1998

A: There's a paleontology department at Monash University - click here for their web site. The links from that web site might help you find more information.



Q: Is there any progress so far on the studies of the bird-like dinosaur found in China and what is it's name?
from Vanessa W., Tulsa, OK, USA; July 7, 1998

A: In the last few years, many fossils of feathered dinosaurs have been found near Yianxin, in Liaoning Province, China. Two new Chinese feathered dinosaurs dating from between 145 and 125 million years ago (during the late Jurassic and early Cretaceous periods) have been found, Protarchaeopteryx robusta and Caudipteryx zoui. Their features are more dinosaur-like than bird-like, and they are considered to be theropod dinosaurs. Their feathers were symmetrical, which indicate that they could not fly (flightless birds have symmetrical feathers while those that fly have asymmetrical ones).

These finds, along with the feathered dinosaur Sinosauropteryx, found a few years ago, reinforce the theory that birds are descended from dinosaurs. For more information on Sinosauropteryx, click here.



Q: what was the first Dinosaur fossil found?
from Danielle, USA; July 7, 1998

A: Megalosaurus was the first dinosaur fossil discovered (in England in 1676). It was also the first dinosaur given a scientific name - by William Buckland in 1824. Megalosaurus trackways have been found in limestone in southern England.



Q: What dinosaurs lived in Spain?
from Bobby B., USA; July 2, 1998

A: Aragosaurus (a 60 foot (18 m) long sauropod), Hypselosaurus (a 27 foot (8 m) long sauropod), and Hypsilophodon (a 7.5 foot (2.3 m) long hypsilophodontid, a bipedal plant-eater) have been found in Spain. For a chart of the locations of dinosaur fossil finds, click here.



Q: What dinosaurs have been found in Connecticut?
from Julie, CT, USA; July 1, 1998

A: Ammosaurus, Anchisaurus, Anchisauripus, Anomoepus, Eubrontes, Gigandipus, Sauropus, and Yaleosaurus have been found n Connecticut. For a chart of the locations of dinosaur fossil finds, click here.



Q: Would you know whether the dinosaurs lost their teeth like we do? Or if they were broken, did they grow back? Thank you and this is a wonderful site.
from Issac and Justine, Italy; June 26, 1998

A: Dinosaurs had replaceable teeth; as teeth became worn or broken they fell out and new ones grew in their places.



Q: If the comet did not hit earth would dinosaurs still live?
from Abe P., Junction City, Kansas, USA; June 24, 1998

A: Even if the comet or asteroid did not hit the Earth, the dinosaurs would probably have evolved and changed somewhat over millions of years. As it is, some bird-like dinosaurs probably DID survive the collision and evolved into the birds.



Q: DO YOU HAVE A CHART THAT HAS THE DIFFERENT DINOSAURS GROUPS' SIZES?
from ANDRE, BALTIMORE, MARYLAND, U.S.; June 23, 1998

A: Here it is. The dinosaurs whose names are underlined are links to information sheets about them.
ORDER SUBORDER INFRA-
ORDER
DINOSAUR FAMILY SOME GENERA TIME RANGE SIZE RANGE
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THEROPODS
Bipedal predators
Herrerasauria Saltopodidae (leaping feet) Saltopus, Eoraptor late Triassic 2-3 feet (0.7-1 m) long
Staurikosaurids (Southern Cross lizards) Staurikosaurus late Triassic 6.5-10 feet (2-3 m) long
Herrerasaurids (Herrera lizards) Herrerasaurus late Triassic to early Jurassic 7-10 feet (2-3 m) long or more
Ceratosauria Coelophysids (hollow form) Coelophysis, Saltopus late Triassic to early Jurassic 2-10 feet (0.6-3 m) long
Ceratosaurids (horned lizards) CeratosaurusSyntarsus Early-Late Cretaceous 11.5-20 feet (3.5-6 m) long
Podokesaurids (swift-footed lizards) Podokesaurus, Syntarsus Early-Late Jurassic 3-10 feet (1-3 m) long
Abelisaurids (Abel's lizard) Abelisaurus, Indosaurus Early-Late Cretaceous up to 36 feet (11 m) long
Noasaurids (lizards from NW Argentina) Noasaurus Late Cretaceous 8 feet (2.4 m) long
Segisauridae (Segi Canyon Arizona lizards) Segisaurus, Dilophosaurus late Triassic to Early Jurassic 20 feet (6 m) long
Coelurosauria Coelurids (hollow tails) Coelurus, Ornitholestes Late Jurassic to Late Cretaceous 4-8 feet (1.2-2.4 m) long
Dryptosaurids (wounding lizards) Dryptosaurus Late Cretaceous +20 feet (6 m) long
Compsognathids (pretty jaw) Compsognathus late Jurassic to early Cretaceous 2-3 feet (0.6-0.9 m) long
Oviraptors (egg thieves) Oviraptor Late Cretaceous 6 feet (1.8 m) long
Caenagnathids (recent jawless) Caenagnathus, Microvenator Late Jurassic to Late Cretaceous 7 feet (2 m) long
Avimimids (bird mimics) Avimimus Late Cretaceous 5 feet (1.5 m) long
Ornithomimids (bird mimics) Ornithomimus Late Jurassic to Late Cretaceous 11.5-19.5 feet (3.5-6 m) long
Garudimimids (Garuda mimics) Garudimimus, Harpymimus Mid-Late Cretaceous 11.6 feet (3.5 m) long
Deinocherids (terrible hands) Deinocheirus Late Cretaceous 45 feet (13.5 m) long (unsure - from incomplete fossils)
Dromaeosaurids (running lizards) Caudipteryx, Deinonychus, Dromaeosaurus, Protarchaeopteryx, Sinornithosaurus, Sinosauropteryx, Unenlagia, Utahraptor, Velociraptor Mid-Jurassic to Late Cretaceous 6-13 feet (1.8-4 m) long
Troödontids (wounding teeth) Troödon Late Cretaceous 6.6 feet (2 m) long
Tyrannosaurids (tyrant lizards) Tyrannosaurus, Albertosaurus, Nanotyrannus Late Cretaceous 16-40 feet (5-12 m) long
Carnosauria Allosaurids (different lizards) Allosaurus, Yangchuanosaurus Late Jurassic 33-42 feet (10-12.8 m) long
Carcharodontosaurids (horned lizards) Carcharodontosaurus, Giganotosaurus Mid - Late Cretaceous 40+ feet (12 m) long
Spinosaurids (thorn lizards) Spinosaurus, Suchomimus Late Jurassic to Late Cretaceous 50 feet (15 m) long
Baryonychids (heavy claws) Baryonyx Early Cretaceous 30 feet (9 m) long
Megalosaurids (giant lizards) Megalosaurus, Altispinax, Erectopus Late Jurassic to Late Cretaceous 23-30 feet (7-9 m) long
Segnosauria Therizinosaurids (scythe lizards) Therizinosaurus Late Cretaceous 35 feet (10.7 m) long
Segnosaurids (slow lizards) Segnosaurus Late Cretaceous 16-30 feet (5-9 m) long
SAUROPODS
Quadrupedal herbivores
Prosauropoda Anchisaurids (near lizards) Anchisaurus Mid-Triassic- Early Jurassic 7-10 feet (2-3 m) long
Plateosaurids (flat lizards) Plateosaurus, Mussaurus late Triassic - Early Jurassic 5-26 feet (1.5-8 m) long
Melanorosaurids (black mountain lizard) Melanorosaurus, Riojasaurus late Triassic- Early Jurassic 19-40 feet (6-12 m) long
Massospondylidae (black mountain lizard) Massospondylus late Triassic to Early Jurassic 13 feet (4 m) long
Sauropoda Cetiosaurids (whale lizards) Cetiosaurus, Protognathus Late Jurassic to Late Cretaceous .
Camarasaurids (chambered lizards) Camarasaurus Late Jurassic to Late Cretaceous 40-60 feet (12-18 m) long
Dicraeosaurids (two-forked lizards) Amargasaurus, Dicraeosaurus, Rebbachisaurus Late Jurassic-Early Cretaceous 33-28 feet (10-20 m) long
Euhelopodids (good marsh feet) Euhelopus, Tienshanosaurus Late Jurassic 33-90 feet (10-27 m) long
Titanosaurids (titanic lizards) Aegyptosaurus, Alamosaurus, Andesaurus, Argentinosaurus, Hypselosaurus, Quaesitosaurus, Saltasaurus, Titanosaurus Late Jurassic to Late Cretaceous 30-70 feet (9-21 m) long
Diplodocids (double-beamed form) Diplodocus, Apatosaurus, Barosaurus, Supersaurus, Seismosaurus Late Jurassic to Late Cretaceous 54-90 feet (16.5-27 m) long
Brachiosaurids (arm lizards) Astrodon, Brachiosaurus, Ultrasauros Mid-Late Jurassic- Early Cretaceous 33-82 feet (10-25 m) long
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ORNITH-
OPODS

herbivores
Fabrosauria, Lesotho-
sauria
Fabrosaurids (Fabre's lizards) Fabrosaurus, Lesothosaurus, Xiaosaurus late Triassic to Early Jurassic 3.3 feet (1 m) long
Heterodontosaurids (different-teeth lizards) Heterodontosaurus late Triassic to Early Jurassic 4 feet (1.2 m) long
Ornithopoda Hypsilophodontids (high-ridged teeth) Hypsilophodon, Orodromeus Mid-Jurassic to Late Cretaceous 3-8 feet (0.9-2.4 m) long
Dryosaurids (oak lizards) Dryosaurus Mid-Jurassic to Early Cretaceous 9-21 feet (2.7-6.5 m) long
Iguanodontids (iguana teeth) Iguanodon, Ouranosaurus, Anoplosaurus Early- Late Cretaceous 13.5-29 feet (4-9 m) long
Camptosaurids (bent lizards) Camptosaurus, Muttaburrasaurus Mid-Jurassic to Late Cretaceous 4-23 feet (1.2-7 m) long
Hadrosaurids (big lizards) Hadrosaurus, Maiasaura, Anatotitan, Edmontosaurus, Saurolophus, Trachodon Late Cretaceous 12-50 feet (3.7-15 m) long
Lambeosaurids (Lambe's lizard) Lambeosaurus, Bactrosaurus, Corythosaurus, Jaxartosaurus, Parasaurolophus Late Cretaceous 13-50 feet (4-15 m) long
Thescelosaurids (wonderful lizards) Thescelosaurus Late Cretaceous 11 feet (3.4 m) long
MARGINO-
CEPHALIA

herbivores
Pachycephalo-
sauria
Pachycephalosaurids (thick-headed lizards) Pachycephalosaurus, Stegoceras, Stygimoloch Early - Late Cretaceous 3-15 feet (0.9-4.6 m) long
Homalocephalids (even-headed forms) Wannanosaurus Late Cretaceous 1.5-10 feet (0.5-3 m) long
Ceratopsia Protoceratopsids (first horned faces) Protoceratops, Bagaceratops, Leptoceratops, Montanoceratops, Notoceratops, Zuniceratops Late Cretaceous 3.3-10 feet (1-3 m) long
Ceratopsidae (horned faces) Anchiceratops, Avaceratops, Arrhinoceratops, Brachyceratops, Ceratops, Monoclonius, Styracosaurus, Torosaurus, Triceratops Late Cretaceous 6-30 feet (1.8-9 m) long
Psittacosaurids (parrot lizards) Psittacosaurus Early Cretaceous 6.5 feet (2 m) long
THYREO-
PHORA
(ENOPLA-
SAURIA)
armored, herbivorous, quadrupeds
x Scutellosaurids (small-shield lizard) Scutellosaurus Early Jurassic to Late Jurassic 2.4 feet (0.6-1.2 m) long
Scelidosaurids (limb lizards) Scelidosaurus Early Jurassic 13 feet (4 m) long
Stegosauria Huayangosaurids (Huayang lizards) Huayangosaurus, Tatisaurus Mid-Jurassic 13 feet (4 m) long
Stegosaurinae (roof lizards) Stegosaurus, Dacentrurus, Kentrosaurus, Tuojiangosaurus, Yingshanosaurus Late Cretaceous 13-30 feet (3-9 m) long
Stegosauridae (roof lizards) Craterosaurus, Regnosaurus Early Cretaceous 13 feet (4 m) long
Ankylosauria Nodosaurids (node lizards) Nodosaurus, Acanthopholis, Brachyspondosaurus, Edmontonia, Hoplitosaurus, Minmi, Hylaeosaurus, Polacanthus, Sauropelta, Struthiosaurus Mid-Jurassic - Late Cretaceous 6-25 feet (1.8-7.6 m) long
Ankylosaurids (fused lizards) Ankylosaurus, Euoplocephalus, Tarchia, Talarurus Early - Late Cretaceous 18-35 feet (5.5-10.7 m) long



Q: Are Dinosaurs warm or cold blooded ?
from ???; June 23, 1998

A: The debate about whether dinosaurs were hot- or cold-blooded is quite controversial. It used to be assumed that dinosaurs were cold-blooded like their reptile ancestors. Some paleontologists have recently argued that at least some dinosaurs were fast, active, competed against hot-blooded mammals, lived in cool areas, were related to birds, and therefore were endothermic (generating their own body heat, or hot-blooded).

Dinosaurs evolved from cold-blooded animals (the reptiles) and evolved into warm-blooded animals (the birds). All dinosaurs, however, were not the same, and perhaps their physiologies differed also. The huge dinosaurs and the tiny dinosaurs might have used different heat-regulation strategies, just as they used different strategies for other aspect of living. A good argument for this is found among modern mammals. Although warm-blooded, there are some mammals (monotremes, the egg-laying mammals like the duck-billed platypus) whose metabolisms are close to being cold-blooded.

Some dinosaurs seem to have had heat regulating structures on their bodies. For example, Spinosaurus and Ouranosaurus had large sails on their backs, and Stegosaurus had numerous plates. These devices were probably used for the collection and dispersion of heat. This suggests that they needed these structures to regulate their body heat and that they were cold-blooded.

Basically, it's difficult or perhaps impossible to answer this question with today's knowledge. There are a lot of people thinking about this, and we'll be hearing a lot more about it soon.



Q: Why are dinosaurs called dinosaurs? we are studying them at school just now and my teacher doesn't know?
Sarah from Ludlow School (aged 7)

from Sarah C., Southampton, England, UK; June 22, 1998

A: The term dinosaur was coined by the English anatomist Sir Richard Owen in 1842. He named large extinct reptile fossils dinosaurs, meaning "terrifying lizards" (in Greek, deinos means terrifying; sauros means lizard). The only three dinosaur fossils known at the time were Megalosaurus, Iguanodon, and Hylaeosaurus, very large dinosaurs.



Q: What are the most recent dinosaur discoveries? Are there any dinosaur fossils in Manitoba?
from Mrs. Klein's Grade One Class, Ste. Rose, Manitoba, CA; June 20, 1998

A: See the Dino News. One of the most important recent dinosaur finds is a tiny theropod (meat-eater) fossil found in Cretaceous limestone in southern Italy near Naples. Although it was unearthed 10 years ago, its true importance was not realized until lately. It is a very important specimen in that it has fossilized impressions of many of its internal organs and muscles. This type of detail is rare in fossils since the soft tissues from an animal do not usually fossilize; they almost always rot before mineral replacement can take place. This new fossil will yield a lot of information about dinosaur's anatomy and physiology as it is studied.

The fossils is a theropod, perhaps a maniraptor (related to Velociraptor). It is a hatchling 9.5 inches (24 cm) long. It is from 113 million years ago (during the Cretaceous period) and has been named Scipionyx samniticus. During the Cretaceous period it lived near a shallow lagoon. (reference: Cristiano Dal Sasso and Marco Signore in Nature, vol. 392 (March 26, 1998):383-387)

I can't find any references to dinosaurs found in Manitoba.



Q: Do you think that there is any foundation to the theory that dinosaurs became exctint due to the fact that they did not adapt their behavior to fit in with changes on earth?
from Emily L., St. Albans, Hertfordshire, England; June 18, 1998

A: Adaptating quickly to change is crucial to survival and the inability to adapt is certainly is a main factor in extinctions. Behavioral adaptations aren't the only ones necesary to survival. Organisms must also adapt physically, for example, they must be able to survive changes in the temperature, the content of the atmosphere, the food that is available, and many other environmental phenomena.



Q: I want to know about dinosaur's habitat.
What dinosaur lived on ground?
What dinosaur lived in sea?
What dinosaur lived on sky?

from Eunice P., LA, CA, USA; June 16, 1998

A: All the dinosaurs lived on land. Some may have gone into the water for short amounts of time, but none lived primarily in the water. Also, no dinosaurs could fly. There were reptiles from the Mesozoic Era that flew (Pterosaurs and others) and many that lived in the seas (Plesiosaurs, Mosasaurs, and others).



Q: We recently visited The Dinosaur State Park in Rocky Hill, Connecticut where we learned that the Black-capped chickadee is a decendant of the dinosaur. How can this be?
from Ed and Nancy C., New Haven, Connecticut, USA; June 15, 1998

A: There is a very popular theory that the birds (all of them, not just the black-capped chickadee) evolved from one line of dinosaurs. In particular, it is theorized that the maniraptors, a group of bird-like dinosaurs, led to the birds. The maniraptors included the Dromaeosaurids, the Troodontids, the Therizinosaurs, the Oviraptors and the Avians (birds). For a more detailed discussion of this theory in Zoom Dinosaurs click here. For a discussion of birds and dinosaurs at the UCMP, Berkeley, click here.



Q: Please tell which was the smallest type of dinosaur. How small was it? What did it eat? Where did it live? Any other interesting things about it? Thank you.
from Yuki S.-R., Tokyo, Japan; June 15, 1998

A: The smallest dinosaur yet found is Compsognathus, a speedy, long-legged meat-eater (eating insects and small animals) about 2 feet (60 cm) long, the size of a chicken. It lived about156-145 million years age, during the late Jurassic period. Its name means "elegant jaw." Its fossils have been found in Germany and France. For more information on Compsognathus, click here.



Q: Where would you look for dinosaurs in Canada? What ones have been found in Canada?
from ???; June 14, 1998

A: Many, many dinosaurs have been found in Canada, including Tyrannosaurus rex, Albertosaurus, Edmontosaurus, Edmontia, Euoplocephalus, Lambeosaurus, Pachycepahlosaurus, Saurolophus, Styracosaurus, Torosaurus, Triceratops, Troödon, and others. More have been found in the province of Alberta than in the other provinces. For a list, click here. Q: Were dinosaurs very smart?
from Jason V., Sapulpa, OK, USA; June 12, 1998

A: They were probably as smart as you would expect a reptile to be. Some may have had brains equivalent to those of primitive birds. The only way we have of judging the intelligence of extinct animals is by comparing the various ratios of brain weight to body weight (this ratio is called the Encephalization quotient or EQ). Assuming that smarter animals have larger brains to body ratios than less intelligent ones, the smartest dinosaurs were the troodontids (including Troodon) and the dromaeosaurid dinosaurs (the "raptors," which included Dromeosaurus, Velociraptor, Deinonychus, Utahraptor, and others).

EQ



Q: A very dumb dinosaur question:
I've heard about a very strange and funny dinosaur extinction theory. It says that the dinosaurs became extinct because they farted too much. Did the dinosaurs really fart (a big sauropod fart or a T.Rex fart must have been stink to high heaven :) ) and is it really possible that this has caused a climatic change milions of years ago that killed the dinosaurs or is it just a dumb joke?

from Bastiaan K., Netherlands; June 11, 1998

A: There is speculation that the large plant-eaters (like the huge ankylosaurs and sauropods) may have had fermentation compartments in their guts in order to help in the digestion of the enormous amounts of tough plant material they needed to eat every day. If so, they would have produced a lot of gaseous by-products, like methane, which could have contributed to atmospheric warming if present in large enough amounts. Whether or not this was a large factor in the catastrophic K-T mass extinction is doubtful.



Q: What dinosaur lied 65 million years ago?
from Shelley S., Cambridge, Waikato, New Zealand; June 10, 1998

A: The following dinosaurs lived (and died) 65 million years ago at the end of the Cretaceous period: T. rex, Maiasaura, Chasmosaurus, Lambeosaurus, Anatotitan, Ankylusaurus, Pachycephalosaurus, Dryptosaurus, Edmontosaurus, Ornithomimus, Alamosaurus, Protoceratops, Alioramus, Antarctosaurus, Argyrosaurus, and many others.



Q: When did dinosaurs first start roaming the earth?
from Fiona R., Cambridge, Waikato, New Zealand; June 10, 1998

A: The earliest known dinosaurs lived about 228 million years ago during the Triassic period.



Q: Could you name two early species of Dinosaurs and the approximate times that they lived on earth
from Kimberly D., cambridge, waikato, New Zealand; June 8, 1998

Eoraptor A: The earliest known dinosaur is Eoraptor, a 3 feet (1 m) long meat-eater that lived in Argentina, South America about 228 million years ago. Another early dinosaur was Herrerasaurus, another meat-eater (about 17 feet or 5 m) which also lived in Argentina about the same time.



Q: HOW DO YOU KNOW THAT DINOSAURS ARE MILLIONS OF YEARS OLD? AND HOW DO YOU DATE THE LAYERS OF ROCK?
from Nate, Lansing, MI, USA; June 8, 1998

A: There are many way of dating dinosaur (or any other) fossils, including radioisotope-dating of the igneous (volcanic) rock that brackets the sediment the fossil in found in, examination of index fossils within the layer, stratiography (examining the depth at which the layer is buried), and observation of the layer's magnetic field. For more information on dating fossils, click here.



Q: I need to know a 'cretaceous dinosaur', 11 letters for a cross word. The third letter is 'A' and the ninth letter is 'O'.
Thanks

from ???; June 8, 1998

A: Avaceratops.



Q: What dinosaurs eat fern in the Triassic period?
from Melissa, Bala Cynwyd, PA, USA; June 7, 1998

A: Herbivorous dinosuars from the Triassic period (that may have eaten ferns) included: Massospondylus, Riojasaurus, Plateosaurus, Fabrosaurus, Lesothosaurus, and others.



Q: What dinosaurs are extremely big and herbivores in the Cretaceous period?
from Julie, Merion, PA, USA; June 7, 1998

A: Large Cretaceous herbivores include Sauropelta, Iguanodon, Tenontosaurus, Brachiosaurus, Ouranosaurus, Yangchuanosaurus, Hylaeosaurus, Maiasaura, Ankylosaurus, Triceratops, Pachycephalosaurus, Parasaurolophus, Corythosaurus, Anatotitan, Euoplocephalus, Lambeosaurus, Edmontosaurus, and many others.

For more information about the Cretaceous period, click here.



Q: Were there any dinosaurs in the triassic or jurassic or creataceous period that ate fish? If so...what dinosaurs and what kinds of fish? Thanks.
from Amy, Merion, PA, USA; June 7, 1998

A: Yes, Baryonyx was an early Cretaceous fish-eater. A fossil of Baryonyx was found in England with fish scales and bones in its stomach. For more information on Baryonyx, click here.



Q: Could you tell me about what happens to the Carbon molecule in the dinosaur, specifically on the Plateosaurus. I know that the dino breathes in Oxygen and carbon molecules bond with the oxygen molecules...but where and how does this occur? How does it breathe out the carbon dioxide?
from Julie, Merion, PA, USA; June 6, 1998

A: All animals with lungs, including the dinosaurs, breathe in the same fashion, taking in Oxygen from the air and exhaling carbon dioxide. Carbon and other necessary elements are obtained from ingesting food.



Q: Do you know if dinosaurs slept standing up or lying down? Thank you,
from Class 2A New Lambton Public School, Australia; June 3, 1998

A: No, no one knows about most of the everyday habits of extinct animals, especially behavior that doesn't leave a physical trace. Some dinosaurs, however, might have had a hard time getting up again after lying down. Some paleontoligists have speculated on how Tyrannosaurus rex could get up from a lying-down position since its arms were so tiny. It might have been a little like a turtle flipping itself over from an upside-down position. Other dinosaurs like the giant sauropods (like Apatosaurus and Supersaurus) would probably have had a hard time getting back up again given their enormous weight. But most dinosaurs were not enormous and didn't have tiny arms so there wouldn't be a physical problem lying down, but no one knows how they slept.



Q: Do you know anything about well-known Australian dinosaurs?
from Class 2A New Lambton Public School, Australia; June 3, 1998

A: Some of the dinosaurs that have been found in Australia are: Agrosaurus, Atlascopcosaurus, Austrosaurus, Fulgurotherium, Leaellynasaura, Minmi, Muttaburrasaurus, and Rhoetosaurus. Which in particular are you interested in? Click here for a list of Australian dinosaurs.



Q: Could you please tell us which dinosaur was the slowest moving? Thank you,
from Class 2A New Lambton Public School, Australia; June 3, 1998

A: Some of the slowest dinosuars must have been the Ankylosaurids which were heavily plated, had bulky bodies and short legs. The Ankylosaurids included Ankylosaurus, Acanthopholis, Euoplocephalus, Hylaeosaurus, and Sauropelta. There are information sheets on each of these dinosaurs at Zoom Dinosaurs , just click on "Dinosaur Information Sheets" and then on the individual dinosaur.



Q: What do dinosaurs eat?
from Gr. 2, East Boston, MA, USA; June 3, 1998

A: Most dinosaurs were herbivores (plant-eaters), some were carnivores (meat-eaters) and a few were omnivores (eating both plant and animal material). Click here to see a section in Zoom Dinosaurs about dinosaurs' diets.



Q: How did dinosaurs evolve into birds? Can you please send me information on that subject.
from David, Algonquin, IL, USA; June 1, 1998

A: Evolution is a process in which the gene pool of a population gradually (over millions of years) changes in response to environmental pressures, natural selection, and genetic mutations. All forms of life came into being by this process.

The dinosaurs came in many different shapes and forms, including some that greatly resembled birds. Some of these bird-like late Cretaceous theropods (which included the dromaeosaurid dinosaurs, the troodontids, and the therizinosaurs) may have evolved into the birds.



Q: Are Velociraptors really the smartest dinosaur? If not where do they fall in line? And where can I find info about them?
from Laura, Algonquin, IL, USA; June 1, 1998

Q: Which dinosaur was the smartest, and where can I find information on it?
from Erin, Algonquin, IL, USA; June 1, 1998

A: The only way we have of judging the intelligence of extinct animals is by comparing the various ratios of brain weight to body weight (this ratio is called the Encephalization quotient or EQ). Assuming that smarter animals have larger brains to body ratios than less intelligent ones, the smartest dinosaurs were the troodontids (including Troodon) and the dromaeosaurid dinosaurs (the "raptors," which included Dromeosaurus, Velociraptor, Deinonychus, Utahraptor, and others).

EQ



Q: Were dinosaurs reptiles or the ancestors of birds?? Many scientists believe they were reptiles; my mother believes they were the ancestors of birds.
from Jimmy, Georgia, USA; June 1, 1998

A: Dinosaurs were reptiles and may have been the ancestors of the birds.



Q: What were the commonest dinosaurs which lived England? EDWARD (age 7)
from Edward, England; May 31, 1998

A: Some of the most common dinosaur fossils found in England are: Iguanodon, Anatosaurus, Cetiosaurus, Dryosaurus, Hylaeosaurus, Megalosaurus, Scelidosaurus, Thecodontosaurus, and Hypsilophodon.



Q: Where do dinosaurs come from?
from David, UT, USA; May 30, 1998

A: Dinosaur eggs.



Q: Did all 330 kinds of dinosaurs have tiny brains?
from Mrs. Leija's 1/2 Multiage class, Estes Park, Colorado, USA; May 28, 1998

A: Yes, to one degree or another. The smartest dinosaurs (the ones with the largest brain:body weight ratio) were the dromaeosaurids. The least intelligent were the sauropodomorpha.
EQ
The EQ or Encephalization Quotient is a simple way of measuring an animal's intelligence. EQ is a ratio of the mass of an animal's brain to the mass of its body. Assuming that smarter animals have larger brains to body ratios than less intelligent ones, this helps determine the relative intelligence of extinct animals. In general, warm-blooded animals (like mammals) have a higher EQ than cold-blooded ones (like reptiles and fish).

The primitive dinosaurs belonging to the clade sauropodomorpha (which included Massospondylus, Riojasaurus, and others) were among the least intelligent of the dinosaurs, with an EQ of about 0.05. The troodontids (including Troodon) and dromaeosaurid dinosaurs (the "raptors," which included Dromeosaurus, Velociraptor, Deinonychus, and others) had the highest EQ among the dinosaurs, about 5.8.


Q: What dinosaur had the most teeth? Hadrosaurus right! Do dinosaurs hibernate?
from IVI, Adelaide, SA, Australia; May 27, 1998

A: Yes, some hadrosaurs had up to 960 teeth! No one knows if any dinosaurs hibernated, but it is unlikely since the dinosaurs lived during a time when the earth was very warm. The earth only started to cool off toward the end of the Mesozoic.



Q: I was told that some dinosaurs were warm blooded. Is that true or is it just a line?
from ??, Brockville, Ontario, Canada; May 25, 1998

A: The debate about whether dinosaurs were hot- or cold-blooded is quite controversial. It used to be assumed that dinosaurs were cold-blooded like their reptile ancestors. Some paleontologists have recently argued that at least some dinosaurs were fast, active, competed against hot-blooded mammals, lived in cool areas, were related to birds, and therefore were endothermic (generating their own body heat, or hot-blooded).

Dinosaurs evolved from cold-blooded animals (the reptiles) and evolved into warm-blooded animals (the birds). All dinosaurs, however, were not the same, and perhaps their physiologies differed also. The huge dinosaurs and the tiny dinosaurs might have used different heat-regulation strategies, just as they used different strategies for other aspect of living. A good argument for this is found among modern mammals. Although warm-blooded, there are some mammals (monotremes, the egg-laying mammals like the duck-billed platypus) whose metabolisms are close to being cold-blooded.

Some dinosaurs seem to have had heat regulating structures on their bodies. For example, Spinosaurus and Ouranosaurus had large sails on their backs, and Stegosaurus had numerous plates. These devices were probably used for the collection and dispersion of heat. This suggests that they needed these structures to regulate their body heat and that they were cold-blooded.

Basically, it's difficult or perhaps impossible to answer this question with today's knowledge. There are a lot of people thinking about this, and we'll be hearing a lot more about it soon.


Q: How do you know what the dinosaur's names were?
from Stacy and Jessie, Grand Ledge, MI, USA; May 22, 1998

A: People name newly discovered dinosaur fossils after they've been found, examined, and it has been determined that they are a new species. The names can reflect characteristics of the dinosaur (for example, Corythosaurus, meaning "helmet lizard," had a helmet-shaped crest on its head), the discoverer or another paleontologist (for example, Lambeosaurus, named for Lawrence Lambe), the place of discovery (for example, Albertosaurus, named for Alberta, Canada, where it was found), or just about anything the namer wants.



Q: when was the high point of the dinosaurs?
from Kyle R., Vancouver, WA, USA; May 21, 1998

A: The dinosaurs were most diverse and abundant during the Cretaceous period, 146-65 million years ago.



Q: When did the great lakes form as ice sheets in North America retreat.
from Murdock; May 17, 1998

A: They formed during the latest ice ages when ice sheets covered most of North America, scraping the northern parts of the continent. They later retreated, leaving lasting landmarks such as the Great Lakes. The ice ages occurred during the Pleistocene epoch, about 20,000 years ago.



Q: I am a student at Columbia College in Chicago doing a paper on dinosaurs classification such as their Kindom, Phylum, Class, Order, Family, Genus, and species but I cannot find any info about them. I need to learn about the T-Rex, Brontosaurus, and Stegosaurus. If you can tell me these, I would greatly appreciate it. Thank you.
from Jaimie, Chicago, IL, USA; May 17, 1998

A: The information you want is in Zoom Dinosaurs. Just click on "Classification" in the left-hand margin, and then on "What are Taxonomy and Cladistics." Stegosaurus stenops is one of the examples given (although "armatus" is the type species of Stegosaurus). The Genus and species of T. rex are Tyrannosaurus (Genus) and rex (species). Brontosaurus is an obsolete name; it has been replaced by Apatosaurus (Genus). The type species of Apatosaurus is "ajax", but there are many other species, including "excelsus", which was the type species for the obsolete Brontosaurus.



Q: Why don't we have anymore animals of the same size of the dinosaurs??
from Dalton, Orlando, FL, USA; May 16, 1998

A: This is a really great question! Unfortunately, it's also one that no one knows the answer to. Although there are water-dwelling animals that are even bigger than any of the dinosaurs (blue whales), there are no modern-day land animals that are even near the size of the enornous sauropods of the Jurassic period. The size of land animal seems to have peaked during the Jurassic period, reaching lengths over 100 feet long (30 m) and weights perhaps up to 100 tons.



Q: This might be a little childish using this when i'm in high school (freshman), but hell this site has what i need. Now i'm doing this report in sience on fact of some different dinosaurs, and i'm wondering if it is pagerism if i copy n paste like a paragraph out of the dinosarus info sheet (i just mean a paragraph not the whole info sheet)? if it isn't would u care if i did?
from Matt, boothwyn, PA, USA; May 15, 1998

A: Yes, it is plagiarism to copy any text verbatim (word for word), even a sentence. You shouldn't do it; have some confidence in your own writing ability.



Q: What was the first meat eating dinosaur?
from Ms. Beaudry, Chicopee, MA, USA; May 15, 1998

Eoraptor A: Eoraptor is the earliest known dinosaur and a carnivore (a meat eater). It lived about 230 million years ago. For an information sheet on Eoraptor, click here.



Q: Which dinosaur is the longest, supersaurus or seismosaurus. I have seen sites that say seismosaurus at 150 feet is the longest.
from W. Etheridge, Palm Harbor, FL, USA; May 14, 1998

Supersaurus A: For many dinosaur species, only incomplete fossils have been found, sometimes just a few bones or teeth. This is true for both Supersaurus and Seismosaurus. In cases like these, guessing about the animal's physiology is the only way to determine a length statistic. There's a lot of room for disagreement between paleontologists here. I have references that estimate Seismosaurus' length ranging from 108-170 feet (33-52 m) long and Supersaurus' length ranging from 80-138 feet (24-42 m) long. Also, there is some disagreement as to whether or not Seismosaurus is a distinct species; some paleontologists think it may be a large example of Diplodocus.



Q: What was the most litte dinosaur?
from Exequiel V., Santiago, Santiago, Chile; May 13, 1998

A: Compsognathus is the smallest dinosaur yet found.



Q: What was the heaviest dinosaur?
from Jay M., West Seneca, NY, USA; May 13, 1998

A: Weight estimates of the dinosaurs are very difficult to determine. The estimates can vary a lot from scientist to scientist, unlike length estimates which are simple to determine and therefore much more consistent.

The enormous Jurassic sauropods were the heaviest dinosaurs, and the most massive of them included Seismosaurus, Brachiosaurus, and Ultrasauros. These dinosaurs may have weighed over 80 tons.



Q: What are the dimensions of the biggest dinosaur footprint?
from Chris, Austin, TX, USA; May 12, 1998

A: The huge Jurassic sauropods left the largest footprints, over 3 feet (1 m) long, and almost as deep. A set of these tracks are on display at the American Museum in New York. Many sets of fossilized sauropod footprints have been found around the world.

When fossil footprints are found, it isn't always known which species left it, but it is usually possible to deterimine what general type of dinosaur made the track, since different types of dinosaurs had different foot structure, (like number of toes and claws, length of toes and claws), toe or heel walking, stance (bipedal vs. quadrupedal), length of stride, etc. Considering the huge size of sauropods and their feet, there is little doubt that when enormous footprints are found, they were from sauropods.



Q: How long did the average dinosaur live?
from Carleigh, Kittery, Maine, USA; May 10, 1998

A: I don't know. It has been estimated that the huge sauropods, like Apatosaurus, Brachiosaurus, Diplodocus, and Supersaurus lived to be about 100 years old. Smaller dinosaurs may have lived shorter life spans.



Q: How many dinosurs were there ?
from Jesse, West Seneca, NY, USA; May 8, 1998

A: About 330 different dinosaur genera have been discovered and many, many more species. More are being found all the time.



Q: What was the first dinosaur that lived?
from Nicole, West Seneca, NY, USA; May 8, 1998

Eoraptor A: Eoraptor is the earliest known dinosaur. It lived about 230 million years ago. For an information sheet on Eoraptor, click here.



Q: What was the tallest dinosaur?
from Jennifer, West Seneca, NY, USA; May 8, 1998

Brachiosaurus A: The tallest dinosaurs were brachiosaurid sauropods; they had front legs that were longer than their back legs and had a giraffe-like stance. They were gigantic, slow moving, tiny-headed, cow-like plant-eaters from the late Jurassic and the Cretaceous period. They had very long necks which were held upright and were useful for reaching wide (and tall) swatches of vegetation. The lengthy neck was counterbalanced by a massive tail. These sauropods included Brachiosaurus, Ultrasauros, and Supersaurus.



Q: What is the fastest Dinosaur?
from Eddie, West Seneca, NY, USA; May 8, 1998

A: The fastest dinosaurs probably weren't any faster than modern-day land animals. The speediest dinosaurs were bird-like bipedal carnivores (theropods) with long, slim hind-limbs and light bodies (hollow bones and a streamlined body):
  • Dromiceiomimus,(means "emu mimic"), an ornithomimid, had long legs, small head, toothless beak, weighed about 220 pounds (100 kg), and was 11.5 feet (3.5 m) long).
  • Ornithomimus (means "bird mimic") -was an ostrich-like oviraptor with a toothless beak, long legs, and hollow bones. Could probably run as fast as an ostrich, , which can run up to 43 mph (70 kph).
  • Coelophysis (means "hollow form") - from the late Triassic period, had very sharp, serrated teeth and hunted in packs.
  • Velociraptor (means "speedy thief") - from the Cretaceous period, had very sharp teeth and retractable claws on its feet .




Q: What was the name and length of the longest known dinosaur?
from M.A. G., West Seneca, NY, USA; May 8, 1998

Supersaurus A: Supersaurus, which was about 134 feet long (41 m), may have been the longest dinosaur. For an information sheet on Supersaurus, click here.



Q: What made dinosaurs extinct?
from Brandon A., Bluefield, West Virginia, USA; May 6, 1998

A: Most dinosaurs went extinct because they couldn't compete with other species - these extinctions are called background extinctions. For those remaining dinosaurs, extinction came at the end of the Mesozoic Era, 65 million years ago. It is theorized that a large asteroid hit the Earth off the coast of Mexico. This impact caused huge environmental changes that the dinosaurs (and many other species) couldn't adapt to, and they died out - this event was called the K-T mass extinction.

For more details about this and other extinction theories, click on "Extinction" in the margin to your left.



Q: How tall was the tallest dinosaur? How small was the smallest dinosaur?
from rodney and jackelin, boston, ma, USA; May 5, 1998

Brachiosaurus A: The tallest dinosaurs were Ultrasauros, Supersaurus, and Brachiosaurus. The smallest, Compsognathus, was about 2 feet (60 cm) long, the size of a chicken. For more extreme dinosaurs, click here.



Q: What Dinosaur lived the longest?
from ashlee, arizona, USA; April 29, 1998

A: The sauropods may have been the longest-lived dinosaurs; they are estimated to have lived for about100 years.



Q: How did sir Richard Owen figure out the dinosaurs names?
from Eric, Meridian, OH, USA; April 26, 1998

A: The British anatomist Richard Owen coined the term dinosaur (meaning "fearfully great lizard") in 1842, and also described and named many dinosaurs, including Bothriospondylus (meaning "trench vertebra"), Cetiosauriscus (meaning "whale-like lizard"), Chondrosteosaurus (meaning "bony-cartilage lizard"), Dacentrurus (meaning "pointed tail"), Dinodocus (meaning "terrible beam"), Echinodon (meaning "spiny tooth"), Massospondylus (meaning "massive vertebrae"), Nuthetes (meaning "monitor lizard"), Polcanthus (meaning "many spines"), and Scelidosaurus (meaning "limb lizard").

Richard Owen, like other namers of dinosaur genera, named dinosaurs however they want to. The names can reflect characteristics of the dinosaur (for example, Corythosaurus, meaning "helmet lizard," had a helmet-shaped crest on its head), the discoverer or another paleontologist (for example, Lambeosaurus, named for Lawrence Lambe), the place of discovery (for example, Albertosaurus, named for Alberta, Canada, where it was found), or just about anything the namer wants.



Q: What is the biggest meat-eating dinosaur in the world?
from ???; April 23, 1998

A: The biggest meat-eaters that have been found so far are Giganotosaurus, Carcharodontosaurus, and Tyrannosaurus rex. Click on the underlined names for more information about those dinosaurs.



Q: Why are dinosaurs so big?
from Melanie M., Glacier Bay, Nova Scotia, CA; April 21, 1998

A: Not all the dinosaurs were big. When dinosaurs first appeared in the Triassic period, they were small; many of them were only a few feet long. Millions of years later, during the Jurassic period, many dinosaurs grew to be enormous, especially some sauropods like Brachiosaurus, Diplodocus, Apatosaurus, and some carnivores, like Megalosaurus. Still, there were many more smaller dinosaurs.

As to why some dinosaurs were so enormous - no one knows. They just filled ecological niches that existed at the time and did very well for a very long time.



Q: Why were dinosaurs extinct?
from Melanie M. and Shalene A., Glacier Bay, Nova Scotia, CA; April 21, 1998

A: Most dinosaurs went extinct because they couldn't compete with other species - these extinctions are called background extinctions. For those remaining dinosaurs, extinction came at the end of the Mesozoic Era, 65 million years ago. It is theorized that a large asteroid hit the Earth off the coast of Mexico. This impact caused huge environmental changes that the dinosaurs (and many other species) couldn't adapt to, and they died out - this event was called the K-T mass extinction.

For more details about this and other extinction theories, click on "Extinction" in the margin to your left.



Q: Do dinosaurs have to sit on their eggs ? If not, why not ?
Thanks.
Sarah M.
2nd. Grade at Cedar Creek Elementary

from Sarah M., Austin, Texas, USA; April 20, 1998

A: Different dinosaurs had very different methods of reproduction. Sauropod dinosaurs (like Diplodocus, Apatosaurus, Brachiosaurus, etc.) laid their eggs on the bare ground while walking, not even making nests for the eggs. They probably did nothing more to nurture the eggs. Other dinosaurs, like Maiasaura constructed huge nests by scooping out holes in the ground. Protoceratops laid eggs in sandy nests and carefully placed the eggs in a spiral pattern. Whether or not these dinosaurs sat on their eggs to keep them warm isn't known, but some of the mothers probably guarded the nests from predators.



Q: Which dinosaur is the longest?
from ?, Phoenix, AZ, USA; April 14, 1998

A: Supersaurus may be the longest dinosaur yet discovered. For an information sheet on Supersaurus, click here. Q: 1) Which dinosaurs lived underwater? 2) where can I get info on them?
from Daniella B., Panorama Ciry, CA, USA; April 4, 1998

A: No dinosaurs lived underwater. There were other primitive reptiles that lived underwater during the time of the dinosaurs, such as:
Plesiosaurs, Ichthyosaurs, and NothosaurusNothosaurs. Click on any of these creatures for more information about them.



Q: What is a dinosaur exactly?
from ??; April 2, 1998

A: A dinosaur is a type of extinct, land-dwelling reptile that lived from about 228 to 65 million years ago, during most of the Mesozoic Era. They were diapsids, animals that have two holes in the upper part of their skulls and two more holes behind their eyes. Dinosaurs had a unique leg structure among reptiles. Their legs stuck out from under their bodies , and did not sprawl out from the sides like other reptiles . For more information, click on "All About Dinosaurs" in the margin to your left.



Q: what dinosaurs ate humans? if any did
from sarah, tulsa, ok, USA; March 31, 1998

A: None. The dinosaurs lived and went extinct millions of years before people evolved.



Q: How many diff. types of dinosaurs are there?
from summer, Port Charlotte, FL, USA; March 31, 1998

A: There are about 330 described dinosaur genera and many, many more different species. Every few months (sometimes weeks), a new species is unearthed. Paleontologists have varying estimates of how many dinosaur genera ever existed; estimates range from about 1,000 to over 10,000. There are a lot of new dinosaur types left to discover!



Q: I'm doing gcse art and need a picture of a dinosaur fossil quick!!! could you send me a website
from del, Suffolk, England; March 28, 1998

A: Try the UCMP (University of California Museum of Paleontology) website - they have a nice fossil collection.



Q: What was the first dinosaur that ever lived?
from Jon P., Muscatine, Iowa, USA; March 27, 1998

Eoraptor A: It hasn't been found yet. Eoraptor (meaning "dawn raptor") is the oldest dinosaur yet found, even older than Herrerasaurus. However, Eoraptor probably wasn't the first dinosaur; it is not the ancestor of all the other dinosaurs that have been found.

For more information on Eoraptor, click here.



Q: What is the tallest dinosaur?
from Katie and Jay, Cleveland, OH, USA; March 26, 1998

A: Brachiosaurus is the tallest dinosaur yet found. It was about 40-50 feet tall. Ultrasauros may be taller, but only an incomplete fossil has been found (and Ultrasauros may actually be just a large Brachiosaurus). For more information on Brachiosaurus, click here.



Q: How did they disappear?
from Whitney, St. Petersburg, FL, USA; March 26, 1998

A: The dinosaurs (and many other groups of animals) probably went exinct after a large asteroid hit the Earth 65 million years ago, changing the Earth's ecosystem faster than the dinosaurs could adapt to it. For more information about this mass extinction, click here or choose "Extinction" in the left-hand margin.



Q: We are a second grade class learning about dinosaurs. We want to know: What was the last living dinosaur on Earth? What was the smallest dinosaur?
from Miss Moore's class, CA, USA; March 25, 1998

A: The last dinosaurs died out in a mass extinction at the end of the Cretaceous period, 65 million years ago. Some of the dinosaur species that died out during that extinction were Tyrannosaurus rex, Protoceratops, Lambeosaurus, Pachycephalosaurus, Parasaurolophus, Maiasaura, and many, many others. The single, last dinosaur is not known.

The smallest dinosaur yet discovered is Compsognathus, which was the size of a chicken. It was a tiny meat-eater that walked on two legs and lived during the Jurassic period. For more information on Compsognathus, click here.



Q: Did dinosaurs have kneecaps?
from Isaac and Justine, Gaeta, Italy; March 25, 1998

A: No



Q: I am a second grade teacher. My school is having a parade in May. Each classroom has a different theme. My theme is dinosaurs. Could you please give me any idea on how to create a SIMPLE costume for my students. I could use your help with anything, even something as simple as a hat.
from Robin Zager, Phil., PA, USA; March 23, 1998

A: Hats made from papier-mâché molded over balloons are probably the simplest. Click here for instructions on how to make papier-mâché dinosaur hats.



Q: I am a second grade teacher and am seeking the "recipe" on how to create "dinosaur eggs" using coffee grounds. I am unsure of the exact procedure, but small model dinos are inserted into the coffee ground mixture and baked at a very low temp. If you know the specifics on this activity, I would appreciate your assistance.:)
from Sandy, Atlanta, TX, USA; March 22, 1998

A: I've never heard of this.



Q: How many different types of dinosaurs were there?
from Rebecca, Hollywood, USA; March 19, 1998

A: Over 300 different genera of dinosaurs have been discovered so far, any many more different species, and more are being found all the time.



Q: Did mammals live during the dino's period?
from Jaimi C., Vassalboro, Maine, USA; March 19, 1998

A: Yes, mammals and dinosaurs both evolved during the Triassic period. Some scientists think that competition from mammals (for example, egg eating) may have contributed to the extinction of the dinosaurs.



Q: How big was the biggest dinosaur ever in the world book of records
from Shawna R., Port Charlotte, FL, USA; March 18, 1998

A: For the biggest dinosaurs and other dinosaur extremes, click on "All About Dinosaurs" in the left-hand margin, and then on "Dinosaur Extremes" at the top of the page.



Q: What is the largest dinosaur bone that has been found by a Paleontologist?
from Michael V., Blue Earth, Minnesota, USA; March 18, 1998

A: One of the largest ever found was the shoulder blade of Supersaurus, a giant sauropod. It was over 6 feet tall and a couple of feet wide. It was found in1972 by James Jensen in western Colorado, USA. Huge sauropod femurs are also larger than people.



Q: What was the biggest man-eating dinosaur?
from Shawna R., Port Charlotte, FL, USA; March 18, 1998

A: The dinosaurs went extinct millions of years before people evolved, so there were no man-eating dinosaurs. The largest meat-eating dinosaurs were Giganotosaurus, T. rex, and perhaps Carcharodontosaurus.



Q: Who invented the term dinosaurs?
from Noelle L., Port Charlotte, FL, USA; March 17, 1998

A: Although dinosaur fossils have been known since 1818, the term dinosaur ("deinos" means terrifying; "sauros" means lizard) was coined by the English anatomist Sir Richard Owen in 1842. The only three dinosaurs known at the time were Megalosaurus, Iguanodon, and Hylaeosaurus, large dinosaurs.



Q: Is there a Dinosaur big than Supersaurus?
from Anthony M., Condor, NC, USA; March 14, 1998

A: Supersaurus may be the biggest dinosaur yet found. Click here for more huge dinosaurs.



Q: In my summer school program, they told us about a dinosaur that spits, or a spitosauraus. Is there such a thing? Thank you!!
from Mark, Woodinville, WA, USA; March 13, 1998

A: I've never heard of it. Also, I'm not sure how the fossil record would indicate that an extinct animal tended to spit.



Q: Is there really a flying dinosaur? This second grade class is not convinced that their is no flying dinosaurs!
from Second Grade Class, Blue Earth, MN, USA; March 12, 1998

A: There were no flying dinosaurs but there were a lot of flying reptiles during the time of the dinosaurs. These flying reptiles were called pterosaurs; examples include Pteranodon and Quetzalocoatlus. They went extinct along with the dinosaurs about 65 million years ago. For more information on pterosaurs, click here.



Q: Our class is researching dinosaurs. We want to know how you can tell if a dinosaur is a plant eater or meat eater. Also, how does a T-Rex attack?
from Mrs. Anderson's class, Ripley Elementary, WV, USA; March 12, 1998

A: Plant eaters and meat eaters are built very differently. Each has specialized teeth, digestive systems, defensive and/or offensive structures and strategies.

Plant eaters (herbiores) usually have blunt teeth that are good for stripping vegetation (leaves, twigs, etc.). Some also have flat teeth for grinding tough plant fibers. Many herbivores have cheek pouches in which they can store food for a while. Plant eaters also usually have larger digestive systems that are needed to digest the tough fibers. Sometimes these dinosaurs swallow rocks to help grind up the fibers in their guts. Some (like Ankylosaurus) even had fermentation chambers, where the fibers were dissolved.

Meat eaters (carnivores) need to have some way to get meat. Carnivorous dinosaurs usually had long, strong legs so that they could run fast in order to catch their prey. They also needed big, strong jaws, sharp teeth and deadly claws that could kill and then tear apart the prey. Good eyesight, a keen sense of smell, and a large brain to plan hunting strategies are also very important for successful hunting. Many of the carnivores (like Deinonychus) may have hunted in packs, so social cooperation was necessary for a good hunt. Scavengers (animals that eat meat that they did not kill themselves) need very sharp teeth and strong jaws for tearing into the meat and breaking the bones for nutritious bone marrow.

T. rex probably attacked by chasing its prey and taking huge bites of flesh with its enormous jaws and slashing the prey with its large toe claws. The loss of blood would kill the prey pretty quickly. T. rex's tiny arms were probably not used in the kill. Click here for more information on T. Rex.



Q: Were there more herbivores or carnivores?
from Mrs. Benjamin, Colchester, VT, USA; March 11, 1998

A: There were many more herbivores. In any food chain, there need to be more organisms at the lower levels of the chain, so the number of carnivores is less than the number of herbivores which is less than the number of plants.



Q: Our class is studying dinosaurs and we were wondering if any of the dinosaurs ate both meat and plants?
Thank you!

from Caitlyn W., Colchester, Vermont, USA; March 10, 1998

A: Most dinosaurs were herbivores (plant eaters), some were carnivores (meat eaters) and only a very rare few were omnivores (eating both plants and animals). Some examples of omnivores are Ornithomimus and Oviraptor, which ate plants, eggs, insects, etc. Also, most herbivores are "accidental omnivores" in that when they are eating plants, they also ingest a lot of insects and small animals.



Q: Why have extinctions occured throughout the history of the Earth.
from ???; March 8, 1998

A: The environment and the organisms on the Earth are continually changing. Those species that cannot adapt or compete with other organisms go extinct. For more information on extinctions, click here.



Q: What is the biggest dinosaur found.
from Jocelin O., Houston, TX, USA; March 7, 1998

A: The giant sauropods from the Jurassic period were the biggest. For more details, click here for a page on dinosaur extremes.



Q: Which type of dinosaur was the meanest and most aggresive that lived in Arizona? Thanks, Zachary G. age 6 Gilbert, AZ
from Zachary G., Gilbert, Arizona, USA; March 6, 1998

A: Dinosaurs weren't mean. The meat eaters only killed other animals in order to survive. Dinosaurs found in Arizona include the meat eaters: Dilophosaurus (a 20 foot long, crested meat eater), Eubrontes (a heavy, 20 foot long carnivore), Segisaurus (a very small, speedy meat eater), and Syntarsus (a small, primitive meat eater). Plant eaters from Arizona include: Ammosaurus ( a prosauropod, a very early, plant-eating dinosaur), Anchisaurus (another prosauropod), Anomoepus (an ornithischian - a vegetarian dinosaur), Chindesaurus (a small prosaurupod), Navahopus (another prosauropod), and Scutellosaurus (a small, primitive armored plant eater).



Q: what information can you give us about gizzard rocks in relationship to dinosaurs.
from First grade class, Tahlequah, OK, Cherokee; March 3, 1998

A: Many plant-eating dinosaurs swallowed small rocks that stayed in their stomachs. These rocks (called gizzard stones or gastroliths) tumbled around in their stomachs, helping to grind up the tough food (leaves, twigs, pine needle, etc.). Some dinosaurs that used gizzard stones were: Apatosaurus, Diplodocus, and Massospondylus.



Q:What color are dinosaurs?
from Alan, Las Cruces, USA; Feb. 26, 1998

A: No one knows.



Q:What is 'Bird-Hipped'?
from John R., Pretoria, Gauteng, South Africa; Feb. 24, 1998

A:Dinosaurs are divided into two groups, the "Bird-Hipped" and the "Lizard-Hipped" dinosaurs.


Q:Is there any evidence to support the claim that dinosauria characteristics involved living in herds?
from Jonathan W., Melbourne, Victoria, Australia; Feb. 21, 1998

A: Some species apparently lived in herds, as revealed by fossil evidence. Evidence includes: many fossils found together in bonebeds (large deposits of bones of the same species in an area), fossilized trackways of many dinosaurs travelling together, or large groups of fossilized nests grouped together.



Q:What were the first dinosaurs?
from ???? Feb. 21, 1998

A: The earliest dinosaurs evolved during the mid-Triassic period, about 230 million years ago. The earliest dinosaurs found so far include Herrerasaurus, Eoraptor, Staurikosaurus, and Lesothosaurus.



Q:How do Dinosaurs Reproduce?
from Mark D., Britton, South Dakota, USA; Feb. 19, 1998

A: Dinosaurs probably reproduced in ways similar to that of modern-day reptiles; for any particular dinosaur body type, find a similar existing reptile type.



Q:If most of the dinosaurs were related to birds, what about the other little bit of the dinosaurs. Were they related to reptiles?
from Brandon C., Canyon, Texas, USA; Feb. 18, 1998

A: Dinosaurs were reptiles. A lot of paleontologists think that birds probably evolved from the dinosaurs. You might want to read the section on dinosaurs and birds in Zoom Dinosaurs; just click on Dino-Birds in the margin to your left.



Q:How many different kind of dinosaurs were there?
from Damon Scott R.-B., Indianapolis, Indiana, USA; Feb. 18, 1998

A: There are about 330 described dinosaur genera and many. many more species. New species are unearthed all the time.



Q:Did all Sauropods travel in a herd? If not, which ones didn't?
from Courtney, Cassie, and Ashley, Boone, IA, USA; Feb. 18, 1998

A: Sauropods probably travelled in herds, as evidence from multiple trackways (fossilized footprints) suggests. The trackways indicate that the young sauropods travelled toward the center of the herd for protection.



Q:How does an dinosaur tear its prey with short little arms?
from John K., warwick, new york, USA; Feb. 17, 1998

A: The short armed dinosaurs, like T. rex and Allosaurus, undoubtably did the most damage with their huge, sharp, strong teeth set in extremely powerful and large jaws.



Q:When was the first Dinosaur born, and when died the last? Why did they die?
from Tim S., Berlin, Germany; Feb. 13, 1998

A: The first dinosaurs evolved during the mid Triassic period, about 230 million years ago; Herrerasaurus is the earliest known dinosaur. It was a bipedal meat-eater, 10 to 20 feet long, weighed about 400 pounds, and hunted in groups.

The dinosaurs died out during the K-T extinction, 65 million years ago. The most widely accepted theory is that an asteroid or meteor hit the Earth (just off the Yucatan peninsula in Mexico), causing huge tidal waves, increasing volcanic activity, and cooling the Earth's temperature. These changes killed a lot of plant and marine species, the dinosaurs, and many animals species in a mass extinction.



Q:Of the majority of all dinosaurs, are they reptiles or birds? I am having a debate in my science class so I need reasons supporting if a dinosaur is a reptile or bird.
from Ryan Y., Washington, Pennsylvania, USA; Feb. 8, 1998

A: Dinosaurs were reptiles. Reptiles are a group of cold-blooded, usually egg-laying vertebrate animals. Lizards, snakes, turtles, crocodilians, and dinosaurs are reptiles.

The class Reptilia is an out-dated Linnaean grouping that doesn't reflect evolutionary history, and introduces some confusion. Using cladistics (an evolutionary approach to classification), dinosaurs, most reptiles (except turtles), and birds are better grouped together as diapsids. Diapsids are distinguished by having two holes in the rear upper part of their skulls and two holes behind their eyes.



Q:1#.What was the deadliest dinosaur?
2#.Did Velociraptor have a bigger terrible claw than Deinonychus?
3#.What was the smartest dinosaur?
4#.What was the size of Velociraptor's terrible claw?

from Ryan P., Milford, NJ, USA; Feb. 5, 1998

A: 1. Deinonychus was certainly a very deadly dinosaur; it was fast, smart, and armed with sickle-like claws.
2. Deinonychus had a bigger claw, and was bigger in general.
3. The only way to estimate the intelligence of dinosaurs is to look at their brain/body weight ratio. The dinosaurs with the largest relative brain weight are the dromaeosaurids (small, bipedal, big-eyed theropods with sickle-like claws), which include: Dromaeosaurus, Deinonychus, Velociraptor, etc.
4. Deinonychus' claw was about 5 inch (13 cm). Velociraptor's claw was smaller.



Q:Which dinosaur is the fastest?
from Susie, Boxboro, MA, USA; Feb. 4, 1998

A: The speediest dinosaurs were bird-like bipedal carnivores (Theropods) with long, slim hind-limbs and light bodies; some of the fastest were:
  • Ornithomimus (means "bird mimic") -was an ostrich-like oviraptor with a toothless beak, long legs, and hollow bones.
  • Velociraptor (means "speedy thief") - from the Cretaceous period, had very sharp teeth and retractable claws on its feet. It was about 6 feet long and and 3 feet tall..



Q:There is a dinosaur which eats only eggs. What is it's name, and what did scientists find that told them that this dinosaur eats eggs? Is it considered a carnivore?
from Matthew S., Santa Barbara, CA, USA; Feb. 3, 1998

A: Any animal that eats eggs is either a carnivore (if it eats only animal material) or an omnivore, (if it also eats plant material).

As to the dinosaur that eats eggs, you might be referring to Oviraptor (meaning "egg stealer"), who, for decades, was thought to eat mostly eggs (along with scavenged meat, insects, berries, etc.). In the 1920's, an Oviraptor fossil was found on top of some eggs (which contained no fossilized embryos), and people assumed that it had been eating the eggs. Recently, however, in Mongolia, paleontologists found some eggs containing fossilized embryos that were identified as embryonic Oviraptors. These eggs were very similar to those eggs found in the 1920's that originally implicated the Oviraptor as a thief. If would seem that the Oviraptor fossil in the 1920's was probably a parent of the eggs in the nest, and not an egg stealer.



Q:Where is the info on individual dino's at?
from Keith B., Il, USA; Jan. 30, 1998

A: Just click on "Dinos and Classification" in the red margin to the left. Then click on the dinosaur you want to learn about.



Q:What was the most dangerous of all dinosaurs.
from Kyle G., Lake Park, GA, USA; Jan. 19, 1998

A: Deinonychus and other raptors were probably the most deadly dinosaurs. Deinonychus (meaning "terrible claw") lived and died during the Cretaceous period, from about 110 to 100 million years ago. Deinonychus was a carnovorous dinosaur that was lightly built, fast-moving, agile, bipedal (walking on two legs), and bird-like. It had a curved, flexible neck and a big head with sharp, serrated teeth in very powerful jaws. Deinonychus lived in the Cretaceous period, about 110 to 100 million years ago.



Q:Who was the first person to discover dinosaurs?
from Daniel R., Buffalo Grove, IL, USA; Jan. 19, 1998

A: The first recognized dinosaur fossils were found by Gideon Mantell, William Buckland, and others, in the early 1800's. The term dinosaur (meaning "fearfully great lizard") wasn't coined until 1842, when Richard Owen classified the fossils as saurians. Three of these early finds were Iguanodon, Megalosaurus, and Hylaeosaurus.



Q:My second grade students and I are currently studying dinosaurs. We would like to know where the most recently discovered nesting sight is and what information can you learn from it?
from Ann G., Boone, Iowa, USA; Jan. 19, 1998

A: Fossils of dinosaurs' burrows and nests can reveal a lot about their behavior, especially the amount of care given to their young. The composition and placement of the nests can also give information about the environment the dinosaurs lived in.



Maiasauras
(meaning "good mother lizard") were the first dinosaurs to be found alongside their young, eggs, and nests. This suggests that they nurtured their young. The nests were holes scooped out of the ground, about 6 feet in diameter (1.8 m), and contained up to 25 grapefruit-sized eggs each. Newborns were about a foot (0.3 m) long. Nests are about 25-30 feet apart, just about the size of an adult Maiasaura. In Montana, one group of over 40 nests covers 2.5 acres (1 hectare) of land that was an island during the late Cretaceous. Maiasaurs were herbivores.

An 80 million year old Oviraptor nesting site was found in Mongolia's Gobi desert. Fossils of this ostrich-like meat-eating dinosaur were found sitting on a nest of eggs. There have been many other nest sites discovered; I'm not sure which discovery of dinosaur nests is the latest.



Q:I'm a second grade teacher. My students would like to know what colors and patterns the dinosaur's bodies were.
from Julie M., Boone, Iowa, USA; Jan. 19, 1998

A: The colors and patterns on dinosaur skin are not preserved in the fossil record. A few examples of fossilized skin have been found, revealing that some dinosaurs had thick, bumpy skin. A 12-year-old girl discovered a T. rex's bumpy skin imprint, confirming that it had a "lightly pebbled skin."



Q:Are sharks dinosaurs or fish?
from Alicia B., Batavia, NY, USA; Jan. 17, 1998

A: Fish.



Q:My second grade class wants to know if there are any dinosaurs living now (or the closest thing to it), and also where we can find out more information on them. Thanks.
from Sharon P., Mingo Junction, Ohio, USA; Jan. 14, 1998

A: There are no dinosaurs alive today. Some scientists thank that the birds are the descendants of the dinosaurs and would therefore qualify as the closest living things. There is more information on this in Zoom Dinosaurs, just click on "Extinction" and "Dino-Birds" in the left margin.



Q:What where the last Dinosaurs to walk the Earth ?
from Sean G., Carleton Place, ON, Canada; Jan. 13, 1998

A: The last dinosaurs lived in the late Cretaceous (about 65 million years ago). A few examples of the last species of dinosaurs include:



Q:Approximatly how many mass extinctions have occurred on Earth in its history? When did the mass extinctions occur,and what were the major life forms that dissappeared?
from Chrystal M, Emma, MO, USA; Jan. 7, 1998

A: A mass extinction is a relatively sudden, global decrease in the diversity of life forms. Mass extinctions have occurred periodically throughout the existence of life on Earth. A graph of major invertebrate extinctions over the last 600 million years. The mass extinctions appear as periodic peaks rising above the background extinction levels. This data is from the work of D. M. Raup and J. J. Sepkoski. There have been many more minor extinctions.

The five largest mass extinctions in Earth's history occurred during:


Q:What was the fastest dinosaur? How fast did it run? How tall was it? How long was it? How much did it weigh?
from Brandon, San Jose, CA, USA; Dec. 30, 1997

A: The fastest dinosaurs probably weren't any faster than modern-day land animals. Dinosaur speeds are deduced from fossilized trackway finds, and from looking at the dinosaurs' morphology (shape and structure). The speediest dinosaurs were bird-like bipedal carnivores (Theropods) with long, slim hind-limbs and light bodies:
  • Ornithomimus (means "bird mimic") -was an ostrich-like oviraptor with a toothless beak, long legs, and hollow bones.
  • Velociraptor (means "speedy thief") - from the Cretaceous period, had very sharp teeth and retractable claws on its feet .
.



Q:Where should I look for dinosaurs in Los Alamitos and what dinosaur will I find or will I discover a new dinosaur?
from Andrew, Los Alamitos, CA, USA; Dec. 25, 1997

A: For information on finding fossils, click on "Fossils" in the margin to your left, and then choose "Finding Fossils." What type of dinosaur you could possibly find depends on what layer (age) of Mesozoic sedimentary rock you're looking in (if there are indeed old, exposed beds of sedimentary rock in Los Alamitos). As for discovering a new dinosaur, it could happen.



Q:Do we know what color dinosaurs were?
from Gregory and Rachel O., Dubuque, IA, USA; Dec. 20, 1997

A: No.



Q:Is the emu the closest living creature to the dinosaur today?
from diane j s., axtell, tx, usa; Dec. 9, 1997

A: A lot of paleontologists think that birds are the living descendants of the dinosaurs. I don't know that the emu, in particular, is any closer to the dinosaurs than any other bird. The emu belongs to the group of primitive birds, the Palaeognathae, that also includes the ostrich, kiwi, emu, rhea, and others. Most other birds belong to the group Neognathae.



Q:How do you figure out the speed of the dinosaurs?
from John R., Anoka, MN, USA; Dec. 9, 1997

A: Dinosaur speeds are estimated using their morphology (things like leg length and estimated body mass) and by using fossilized trackways (footprints). There's a good page on Deducing the Possible Speeds of Dinosaurs? at the University of California's Museum of Paleontology.



Q:How do people know what the dinosaurs ate? (what animals and what kind of plants) Also how do you know what color the dinosaurs were?
from Sybil M., Overland Park, Kansas, USA; Dec. 7, 1997

A: Some dinosaurs have been found with fossilized remains of bones, insects, etc. inside them, showing the contents of their last meal. Also, dinosuaurs' physiology gives us an indication of their diet. An animal with razor-sharp teeth and claws probably was a carnivore; one with flat teeth and gullet stones probably ate plants. \
No one knows what color the dinosaurs were; skin coloration is not preserved in fossils.



Q:Are dinosaurs mammals, birds, or reptiles?
from Alex, MN, USA; Dec. 7, 1997

A: Reptiles.



Q:Could you give me a alphabet on dinosaurs example:A=Avaceratops B=Brontosaurus C=Carnataurus .PLEASE!!!!!!
from Samantha B., Edinburgh, Scotland; Dec. 6, 1997

A: Click here for a Dinosaur Alphabet.



Q:Hi Im Three years old and learning about dinasours with my mum. I would like to see more pictures with the names of dinasours and the name the are commonly know as if that is possible?
from Andrew, Ottawa, Ontario, Canada; Dec. 4, 1997

A: If you click here, there's a page of dinosaur names and pictures; also, if you click on them, you'll get more information and bigger pictures. By the way, dinosaurs are one of the few types of animals who are commonly known by their scientific name.



Q:How many different types of dinosaurs have been found?
from Betty S., Colorado, USA; Dec. 4, 1997

A: There are about 330 described dinosaur genera and many, many more species. Every few months (sometimes weeks), a new species is unearthed.



Q:What is the fastest dinosaur?
from Brian D., Houston, TX, USA; Dec. 3, 1997

Q:What was the fastest running dinosaur?
from George D., Houston, TX, USA; Dec. 3, 1997

A: The fastest dinosaurs probably weren't any faster than modern-day land animals. Dinosaur speeds are deduced from fossilized trackway finds, and from looking at the dinosaurs' morphology (shape and structure). The speediest dinosaurs were bird-like bipedal carnivores (Theropods) with long, slim hind-limbs and light bodies:
  • Ornithomimus (means "bird mimic") -was an ostrich-like oviraptor with a toothless beak, long legs, and hollow bones.
  • Velociraptor (means "speedy thief") - from the Cretaceous period, had very sharp teeth and retractable claws on its feet .




Q:What kind of bugs lived in the dinosaur time ?
from Didi, Sudbury, Ontario, Canada; Dec. 1, 1997

A: Primitive insects first evolved during the Silurian Period (438 to 408 million years ago), long before the dinosaurs appeared. Winged insects appeared later, during the Mississippian Period (360 to 325 million years ago), but they still predated the dinosaurs. A lot of insects lived during the Mesozoic Era (248 to 65 million years ago), the time of the dinosaurs. There were huge dragonflies (as large as birds), giant roaches, and lots of other bugs. The fossil record of insects is very incomplete because their fragile exoskeletons decompose quickly after death, and therefore don't fossilize easily.



Q: Question #1-What is the name of a dinosaur that lived in the water? Question #2-What is the name of a dinosaur with a big fin on its back? Question #3- Which dinosaur walked on two feet?
from Alyssa F., Whitehorse, Yukon, CA; November 29, 1997

A: #1. No dinosaurs lived in the seas - they all lived on land!. Many aquatic animals (such as the Plesiosaur) lived in the seas, but these sea reptiles were NOT dinosaurs.
#2. You might be thinking of the Dimetrodon, the most common finback, but it was not a dinosaur, but another type of prehistoric reptile. Acrocanthosaurus, Ouranosaurus and Spinosaurus are some dinosaurs with sailbacks (or at least, spines along the backbone).
#3. A lot of dinosaurs walked on two feet, including the very early dinosaurs and many later models. Some well-known examples are: Tyrannosaurus, Unenlagia, Pachycephalosaurus, and many, many more.



Q:What date was the first dinosaur found? What type of dinosaur was it? Who found it?
from Bradsky, CT, USA; November 25, 1997

A: The first dinosaur fossils were found by Gideon Mantell, William Buckland, and others, in the early 1800's. The term dinosaur (meaning "fearfully great lizard") wasn't coined until 1842, when Richard Owen classified the fossils as saurians. Three of these early finds were Iguanodon, Megalosaurus, and Hylaeosaurus.



Q:how did the dinosaurs become extinct?????
from brent g., Loveland, Colorado, USA; Dec. 2, 1997
Q:How did the dinosaurs DIE?
from brianna, San Leandro, CA, USA; Nov. 15, 1997

A: Most dinosaur species went extinct during the Mesozoic Era in background extinctions. At the end of the Cretaceous period, there was a mass extinction (the K-T extinction), probably caused by collision with a meteor. Click on the section on "Extinction" on the left margin for more detailed information.



Q: How long ago were the dinosaurs around and what really happened to them?
from Matthew W., Chattanooga, Tennessee, U.S.A.; Nov. 6, 1997

A: Dinosaurs lived during the Mesozoic Era, from about 230 to 65 million years ago. The dinosaurs (except the birds) went extinct 65 million years ago, probably due to the aftereffects of an asteroid impact at the Yucatan Peninsula. These aftereffects included dust and acidic gases in the atmosphere, increased volcanic activity and tsunamis, lowered global temperatures and atmospheric oxygen. These changes caused the K-T mass extinction in which 35% of all animal families died out, together with many plant species. If you click on the word "Extinction" on the left margin of Zoom DInosaurs, you'll find a lot more information.



Q:How fast can a raptor run?
from Marc C., Taytay, Rizal, Phillipines; Oct. 30, 1997

A: The raptors were probably among the fastest of the dinosaurs. Dinosaur speeds are deduced from fossilized trackway finds, and from looking at the dinosaurs' morphology (shape and structure). Exact speeds are not known, but most scientists agree that dinosaurs were not any faster than modern animals. Finding a similarly built modern animal is a good way to estimate some dinosaur speeds.



Q:What are some of the differences between herbivours and carnivours besides one being a plant eater and the other a meat eater?
from Lyndsey, Boston, Massachusetts, USA; Oct. 29, 1997

A: There are a lot of physiological differences between plant eaters (herbivores) and meat eaters (carnivores) that allow them to obtain nourishment.

Carnivores generally need sharp teeth in strong jaws to grasp and tear apart their prey, claws to help in the attack, long legs for speed in order to catch the prey, and sometimes limbs to grab the prey.

Herbivores need teeth that strip plants of their foliage, and a means to defend themselves against predators (like armor, horns or spikes, huge size, camouflage, and/or a tough, thick hide) or speed to escape from them. Sometimes they also need a gullet, a second stomach or a fermentation compartment to aid in the digestion of tough plant material.



Q:What is a theropod?
from Ben H., Geraldton, W.A., Australia; Oct. 19, 1997

A: A theropod ("beast-footed") is a type of Saurischian dinosaur (Saurischians' hip structure is similar to that of lizards). Theropods were two-legged carnivores with well-developed jaw muscles, sharp teeth, clawed hands with three main digits, three-toes on clawed feet, and good eyesight. Some examples of theropods are Albertosaurus, Allosaurus, Giganotosaursus, T. rex, Unenlagia, and Velociraptor.





Q:Q1: Which dinosaur was the most intelligent of all dinosaurs?
Q2: Which dinosaur was the most deadliest?
Q3: Which dinosaur had the most armour?

from Kevin, Canberra, A.C.T., Australia; Oct. 17, 1997

A: A1: The most intelligent may have been Troodon, a bird-like dinosaur that was as smart as an ostrich.
A2: Deinonychus and other raptors were probably the most deadly.
A3: Ankylosaurs were the most heavily armored.



Q:Can you list a family chart of the dinosaurs?
from Alex T., Eden Prairie, Minnesota, USA; Oct. 14, 1997

A: A really nice way to organize families of organisms is by using cladograms. A cladogram is a branching diagram that depicts species divergence from common ancestors. They show the distribution and origins of shared characteristics. Cladograms are testable hypotheses of phylogenetic relationships. Dinosauria On-line has a huge cladogram of the dinosaur species. For more on taxonomy (the science of classifying organisms), click on "Species and Classification" to the left.



Q:When and where did archaeologists find the first dinosaur?
from patrick m., norfolk, va, USA; Oct. 8, 1997

A: The first dinosaur fossils were found by in England by Gideon Mantell, William Buckland, and others, in the early 1800's. The term dinosaur (meaning "fearfully great lizard") wasn't coined until 1842, when Richard Owen classified the fossils as saurians. Three of these early finds were Iguanodon, Megalosaurus, and Hylaeosaurus.



Q: I read in your answers that all dinosaurs lived on land. I thought the plesiosaur had flippers and lived in the water. Is there such a thing as a plesiosaur or any other flippered dinosaur.
from Julie L., New Bavaria, OH, USA; September 28, 1997

A: Plesiosaurs were sea reptiles (with flippers) that lived in the seas during the Late Triassic and Jurassic Periods. They were carnivores that grew to be about 10-14 feet long (3-4 m). Elasmosaurus was another flippered reptile, even bigger than the Plesiosaur, growing up to 40 feet (12 m) long. They were not dinosaurs! No dinosaurs lived in the seas - all dinosaurs lived on land!



Q: I should like to find out: What was the largest dinosaur in the sea, and the information on it. Thanx !
from Sheridan L., manassas, va, USA; September 17, 1997

A: No dinosaurs lived in the seas - they all lived on land!



Q: What is the top speed of each dinosaur?
from Ryan P., Milford, NJ, USA; September 13, 1997

A: Hundreds of different dinosaur species have been found. They come in vastly different sizes, weights, and shapes. The dinosaurs ranged in speed from the very fast, small, light, agile, bird-like dinosaurs to the huge, lumbering, plated Ankylosaurids who had little need for speed. The fast ones probably needed their speed to catch prey or escape from predators. Some of the slowest ones had short legs under massive bodies, had protection from predators, and ate plants. For example, Ankylosaurids had heavy plating for protection from predators, short legs, and a huge gut required by their herbivorous diet (to accomodate large volumes of leaves in a fermenting chamber).

Dinosaur speeds are determined from fossilized tracks and the dinosaur's estimated mass and leg length. One difficulty is identifying the species that made a particular fossilized trackway, given only footprints. When possible, analogies to existing animals are made. The dinosaurs probably had speeds that are approximately like those of modern animals, ranging from plodders to swift runners. There are formulas for determining speeds that were developed by Alexander (Alexander, R. M. 1989. Dynamics of Dinosaurs and Other Extinct Giants, Columbia University Press, New York, USA). Alexander estimates that the fastest sprints were about 25 miles per hour (40 km/hr), although the dinosaurs rarely ran (like most animals, they only run when they have to). Most tracks showed unhurried speeds of 1-7 mph (2-12 km/hr).



Q: I was wondering if Dinosaurs are warmblooded or coldblooded. Also, I would like to know what the difference is.
from Sarah Near D.C., Maryland, Earth; September 9, 1997

A: Dear Earthling,
The debate about whether dinosaurs were warm- or cold-blooded is quite controversial. It used to be assumed that dinosaurs were cold-blooded like their reptile ancestors. Some paleontologists have recently argued that at least some dinosaurs were fast, active, competed against warm-blooded mammals, lived in cool areas, were related to birds, and therefore were endothermic (generating their body own heat, or warm-blooded).

Dinosaurs evolved from cold-blooded animals (the reptiles) and evolved into warm-blooded animals (the birds). Dinosaurs were apparently different from other reptiles, given their dominance on Earth for millions of years. All dinosaurs, however, were not the same, and perhaps their physiologies differed also. The huge dinosaurs and the tiny dinosaurs might have used different heat-regulation strategies, just as they used different strategies for other aspect of living. A good argument for this is found among modern mammals. Although warm-blooded, there are some mammals (monotremes, the egg-laying mammals like the duck-billed platypus) whose metabolisms are close to being cold-blooded.

Basically, it's difficult or perhaps impossible to answer this question. There are a lot of people thinking about this, and I'm sure we'll be hearing more about it.



Q: What is the smallest dinosaur?
from Reza, Melbourne, Victoria, Australia; September 5, 1997

A: Compsognathus is the smallest dinosaur fossil yet found. Compsognathus, meaning "pretty jaw," was a late Jurassic Theropod the size of a chicken (2 feet = 60 cm long weighing about 6.5 pounds = 3 kg). It was a bi-pedal (walked on two legs) carnivore with sharp teeth and claws on its fingers.

Of course, some people would say that the smallest dinosaur is the bee hummingbird (the smallest bird), which is 2.5 inches long ( 6.2 cm) and weighs only 0.06 oz (1.6 g).



Q: I am doing an assingnment for school and I would like to know "What they ate,when they lived, how they looked, size, how they moved, and there strength."
from Amanda, Totowa, NJ, USA; September 4, 1997

A: That's a really vague question! All of this is covered in Zoom Dinosaurs, just look in the sections on "All About" (for general info on dinosaurs and anatomy), "Species and Classification" (for sizes, appearance, diet, etc. of individual species), and "Mesozoic" (for detailed info on when various species lived).



Q: How do dinosaurs mate?
from another mystery person; September 1, 1997

A: Nothing is known about mating postures, rituals, partner selection, or any other details. A good guess would be to find similarly built modern reptiles and assume some similarity. Of course, this is difficult for some species, especially spiked species like Stegosaurus!



Q: What was the first dinosaur????
from Courtney, Northwest Iowa, USA; August 29, 1997

A: The oldest dinosaurs yet discovered date from about 230 million years ago, during the middle of the Triassic period. Early dinosaurs include Eoraptor, Herrerasaurus, Staurikosaurus (a primitive Saurischian) and Lesothosaurus (a primitive Ornithischian). Herrerasaurus was lightly built (it weighing about 400 pounds), fast, and small, about 10-20 feet long (3-6 m). It walked on two legs, ate meat, and hunted in groups.



Q: WHAT IS THE BIGGEST DINOSAUR FOSSIL EVER FOUND?
from MARC I.G. C., ANTIPOLO, RIZAL, PHILIPPINES; August 29, 1997

A: The biggest dinosaurs whose fossils have ever been found are sauropods from the Jurassic period (from 208-146 millions of years ago), gigantic, long-necked, long-tailed, plant-eaters (herbivores) that were well over 100 feet (30 meters) long, and weighed over 100 tons! The sizes of a lot of dinosaurs are estimated from incomplete skeletons, sometimes of just one or a few examples of the species, so the length is sometimes an educated guess. Among the biggest sauropods were:
  • Supersaurus - 134 feet long (41 m)
  • Argentinosaurus - 115-130 feet long (35-40 m); 80-100 metric tons
  • Seismosaurus ("Earth-shaking lizard") - 120+ feet long (37 m); +80 tons
  • Ultrasauros - 100 feet long (30 m), 80 tons, 138 million years ago
  • Diplodocus - grew up to 100 feet long (30 m), 100 million years ago.
  • Apatosaurus - from 70-95 feet long (21 m), weighed about 30 tons (27,000 kg).


Q: What is the definition of a dinosaur?
from (We had a power outage and your question was partially deleted; if you'd like to add in your name, etc., please write again!); August 28, 1997

A: Dinosaurs were land-dwelling reptiles that walked with an erect stance. They had a unique hip structure that caused their legs to stick out from under their bodies, unlike other reptiles, whose legs sprawl out from the side. Dinosaurs also had reduced fourth and fifth digits on their hands; their feet had three large toes. Dinosaurs lived during most of the Mesozoic Era (from 230-65 million years ago). Birds are probably their living descendants. See the section on dinosaurs' "Anatomy and Physiology" for more information (it's listed under the "All About Dinosaurs" section).


Q: I read a book called "Dinosaurs" when I was reading it said that a poisoned ball came down and hit the Triceratops. After that all the dinosaurs ate it is that true???
from Courtney, Northwest, Iowa, USA; August 18, 1997

A: I've never heard of this poisoned ball theory. I think that it's more likely that an asteroid (which is a rock from outer space, similar in composition to the inner Earth) hit the Earth. The dust and debris from the impact drastically changed conditions on Earth. One effect was a decrease in temperature which killed a lot of plants and other life forms. This disrupted the food chain and probably changed the atmospheric and marine oxygen concentrations, killing more and more species. If you click on the word "Extinction" on the left margin of Zoom Dinosaurs, you'll find a lot more information about the Alvarez Theory and other theories of dinosaur extinction.


Q: Why did the dinosaurs die?
from karjani, Los Angeles, CA, USA ; August 14, 1997

A: The dinosaurs (except the birds) went extinct 65 million years ago, probably due to the after-effects of an asteroid impact at the Yucatan Peninsula. These environmental changes included dust and acidic gases in the atmosphere, increased volcanic activity and tsunamis, lowered global temperatures and atmospheric oxygen. These changes caused the K-T mass extinction in which 35% of all animal families died out, together with many plant species. If you click on the word "Extinction" on the left margin of Zoom DInosaurs, you'll find a lot more information.


Q: Why is there such a difference in the size of dinosaurs? Some were as small as chickens, yet others grew to be more than a hundred tons.
from Charley C., Orlando, Florida, US; August 11, 1997

A: Dinosaurs ranged in size from the bird-like Apodiformes and Compsognathus that was 2 feet long (60 cm), weighing as little as 6.5 pounds (3 kg), up to giant sauropods that were up to 130 feet long (40 m), weighing up to 100 tons.

The huge range in dinosaur sizes is related to their evolutionary development and their dominance over other life forms during the Mesozoic Era. Toward the beginning of the Mesozoic, when dinosaurs were just beginning to appear, the ecospace was relatively empty after the catastrophic Permian mass exctinction (248 million years ago). In that extinction, 50% of existing animal families were decimated, leaving a lot of empty niches (places and sitiuations suitable for life forms) for new life forms to occupy.

As the dinosaurs evolved from more primitive reptiles, they were able to out-compete most other medium-to-large land animals, filling a huge range of niches. Their competetive edge was probably due to many factors, including their unique hip structure which allowed them to have a more upright stance than other reptiles, giving them speed and agility, and also the mechanical structure enabling the evolution of great size. Other advantages might have included better nurturing of their young, increasing reproductive survival, adaptation to the hot, dry climate, and perhaps even exothermy (a warm-blooded metabolism).

With all these advantages over previous reptiles and a virtually empty Earth, the dinosaurs radiated all over Pangaea , filling available niches. The dinosaurs started as small, fast, upright meat-eaters, but during the late Triassic, Jurassic and Cretaceous periods, they evolved into both larger and smaller species, meat and plant eaters, upright and quadruped walkers, fast and slow movers, armored and unprotected varieties, and more.

As to the size range of dinosaurs, there are many advantages to being large, including moving into almost empty niches, protection against predators, enhanced killing ability, a decreased ratio of surface area to volume which conserves body heat (allowing dinosaurs to live in relatively cold areas), and other economies of scale. The smaller dinosaurs had their own survival advantages, including speed, agility, the ability to hide, etc. Dinosaurs apparently didn't get very small, probably because of intense competition from other small reptiles and from the newly evolved mouse-sized mammals.


Q: 1.- What dinosaur was the most assasin? 2.- was the long neck dinosaur able to kill a tyrannosaurus? 3.- was a tyrannosaurus able to bite a bhatosaurus? please answer me I am a 6 year old kid.
from carlitos m., matamoros, tamaulipas, mexico; August 10, 1997

A: You ask amazing questions for a 6-year-old! 1. The most vicious dinosaurs were speedy, bird-like predators armed with huge claws, sharp teeth, and wing-like arms that gave them more stability and mobility during a chase. They could outrun most other dinosaurs and then eat them. Examples of deadly predators include:
Deinonychus (meaning killer claw), a bird-like dinosaur 20 feet (6.5 m) long with sickle-like claws (15 inches = 35 cm long) and sharp teeth;
Utahraptor (related to Velociraptor), a small, fast, relatively intelligent carnivore with long, serrated teeth. It had a 15 inch (40 cm) claw on the middle of each foot. This claw could probably slash its prey to death. It may have hunted in herds, killing even large sauropods.

2. The long-necked dinosaurs (the enormous sauropods, like Diplodocus and Apatosaurus ) probably couldn't kill large predators like Tyrannosaurus . The really long-necked dinosaurs lived a long time before Tyrannosaurus did, so they could never meet! Even if they could have met, Apatosaurus would have had a hard time killing a Tyrannosaurus. Apatosaurus was heavier and longer than Tyrannosaurus, was very slow, had tiny jaws and teeth that were only useful for eating plants. Its neck probably made it an easy target for big meat-eaters, which had big jaws and teeth, sharp claws, ran much faster, and ate big dinosaurs for lunch!

3. Tyrannosaurus and Apatosaurus (Brontosaurus) didn't live at the same time. Tyrannosaurus lived about 67-65 million years ago (late in the Creataceous period), while Apatosaurus lived about 140 million years ago (late in the Jurassic period). They never met, but if they had, Tyrannosaurus certainly could have bitten the Apatosaurus.



Q: What was the first dinosaur on earth ?
from roberto m., matamoros, tamaulipas, mexico; August 10, 1997

A: The oldest dinosaurs yet discovered are Eoraptor, Staurikosaurus (a primitive Saurischian), Lesothosaurus (a primitive Ornithischian), and Herrerasaurus, dating from about 230 million years ago, during the middle of the Triassic period. Herrerasaurus was lightly built (weighing about 400 pounds), fast, and small, about 10-20 feet long (3-6 m). It walked on two legs, ate meat, and hunted in groups.



Q: Can you give me any information about oxygen levels during the K-T Boundary period? I read something about a "suffocation theory" which proposed that the dinosaurs did not have diaphragms, and had tiny nostrils. Supposedly when the oxygen levels dropped, they suffocated. Is there any evidence of a drop in oxygen levels from air trapped in canada?
from Karen, Pert, Western Australia; August 10, 1997

A: I haven't heard of that particular theory, but it sounds interesting. Although paleontologists have usually focused on temperature as the major killing agent in extinction theories, your point about the importance of oxygen levels is excellent.

There is evidence of lowered oxygen levels during the huge Permian extinction (248 million years ago). Paul Wignall, et al. (Leeds University, England) estimates that the ocean's oxygen was severely reduced (to one-fifth of its original levels), decimating oceanic life. Also, it has been estimated that atmospheric oxygen levels went from about 30% to about 15% during the Permian extinction, probably suffocating many land animals.

Although the Permian extinction was much larger than the K-T extinction and the causes of these extinctions may well be different, it would seem likely that any drastic changes in the numbers of phytoplankton and plants would result in changes in oxygen levels. This would, in turn, result in the suffocation of species which were unable to adapt.

As to finding physical evidence about ancient oxygen levels, geologists look at oceanic black shale and pyrites, which can only form without oxygen. I don't know if past oxygen levels have been obtained from air trapped in amber.



Q: Can you show us a flow chart of how dinosaur fossils are formed?
from ?; August 9, 1997

A:Here's a flow chart of fossil formation:

Fossil Formation Flowchart



Q: Are alligators older than dinosaurs?
from Felipe, Hollywood, Florida, USA; August 8, 1997

A: Primitive Crocodyloformes (the extinct ancestors of alligators and crocodiles) first appeared during the Triassic period (about 248-208 million years ago). This is also the time when small, primitive dinosaur species began appearing. The oldest Crocodylians (the group that includes the living alligators, crocodiles, etc. and their close extinct relatives) are from the late Cretaceous (about 80 million years ago), which was the heyday of the dinosaurs.



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