|You might also like:||Dinosaur Families||Dinosaur Anatomy and Behavior||Dinosaur Genus List - A||Dino News||Dinosaur Extinction||Today's featured page: Twinkle, Twinkle Little Star Printout|
|What are Taxonomy and Cladistics||How Are Dinosaurs Classified?||Dinosaur Genera||Not Dinosaurs, but Old and Interesting|
|Major Dinosaur Families||Saurischian Dinosaurs
|"Lizard-Hipped" dinosaurs (Saurischians) had a hip structure similar to that of lizards. Oddly enough, these "Lizard-Hipped" dinosaurs were the ancestors of the birds.
Other anatomical features that characterize saurischians include an opening below the nostrils (called the subnarial foramen), an elongation on some neck vertebrae (resulting in long necks), a big thumb, an extra, wedge-shaped ankle bone (the astragalus), and many other distinctive features.
The oldest known dinosaurs are Saurischians from the mid-Triassic period, about 230 million years ago.
Saurischians included both meat and plant eaters.
|"Bird-Hipped" dinosaurs (Ornithischians) had a hip structure that is similar to that of birds (but did not lead to the birds).
They also had beak-like bone in the lower jaw in front of the teeth, called a predentary. Other anatomical differences include a narrow palebral (the bone that crosses the outside of the eye socket), and bony (ossified) tendons above the sacral area of the vertebrae.
The Ornithischian dinosaurs were vegetarians and included plated, armored, and horned dinosaurs.
|Example of "Lizard-Hipped" dinosaurs include:||Example of "Bird-Hipped" dinosaurs include:
|A cladogram of reptilia
Over 35,000 Web Pages
Sample Pages for Prospective Subscribers, or click below
Overview of Site|
Enchanted Learning Home
Monthly Activity Calendar
Books to Print
Parts of Speech
The Test of Time
TapQuiz Maps - free iPhone Geography Game
Biology Label Printouts
Physical Sciences: K-12
Art and Artists
Label Me! Printouts
|Search the Enchanted Learning website for:|