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||Huge Group of Eggs Found, Including Fossilized Embryos and Embryonic Skin
November 17, 1998
Thousands of fossilized dinosaur eggs have been found in the province of Neuquen in northwestern Patagonia, Argentina, South America. This incredible nesting site contains dozens of egg fragments, the first fossilized sauropod embryos, the first embryo skin from any dinosaur, and the first dinosaur egg from the Southern Hemisphere.
The eggs are from large, long-necked, whip-tailed, small-headed, plant-eating, armored dinosaurs. The grown dinosaurs would have been about 40 to 50 feet (12 to 15 m) long and were called Titanosaurs (meaning "giant lizards"). The hatchlings (newly hatched dinosaur chicks) would have been about 12 inches to 15 inches (30 cm to 38 cm) long. The eggs were around 5 to 6 inches (12.7 cm to 15.2 cm) in diameter. The anatomy of bones and teeth revealed that they were young sauropod dinosaurs, a class of long-necked quadrupedal plant-eaters. The embryos had tiny teeth about 1/10th of an inch (.25 cm) long. It is not certain whether or the not the eggs had been laid in nests.
The fossilized skin of the embryo reveals incredibly fine details of scales. Over 70 egg fragments contained fossilized bits of skin, but no complete embryonic skeletons were found. Finding fossilized embryos is a rarity (only 5 other fossilized embryo species have been found) because they are so delicate and are usually crushed and then decompose instead of being preserved by fossilization.
This amazing find dates from the late Cretaceous period, about 70 to 90 million years ago. A major catastrophe, like a flood or mud-flow must have struck a large dinosaur nesting ground. The sudden burial in silt kept the eggs well-preserved and led to their fossilization.
Finding all these eggs in a single nesting ground also reveals some information about this dinosaur's behavior. It congregated in herds, at least to lay eggs, and may have been a social animal.
The site was discovered last year near Auca Mahuida and covers about one square mile of badlands. It has been named "Auca Mahuevo" (huevos means eggs in Spanish). This find is reported in the November 19 issue of the magazine Nature.
More information on eggs and other trace fossils.
Information about Dinosaur reproduction and eggs
Information on sauropod dinosaurs.
How animals fossilize.
All about the Cretaceous period.
Other fossils found in South America.
Chart of geological time
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