Apatosaurus
genus of apatosaurs / From Wikipedia, the free encyclopedia
APATOSAURUS is a sauropod dinosaur which lived in the Upper Jurassic period. It is in the same family as Diplodocus. Brontosaurus was once thought a later name for Apatosaurus, but is now proved to be a separate genus.
Apatosaurus Temporal range: Upper Jurassic
152–150 mya | |
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A. louisae skeleton, Carnegie Museum | |
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Genus: | Apatosaurus Marsh, 1877 |
Apatosaurus grew as big as 21 meters long, 4.5 meters tall at the hip, and weighed up to 23 metric tons. It ate plants. Its bones have been found in Wyoming, Colorado, Oklahoma, and Utah.
When it was first found, scientists thought that Apatosaurus lived partly under water, as if it could not hold its own weight on dry land. Now they think it lived on dry land, probably in herds.
The cervical vertebrae were less elongated and more solid than those of Diplodocus. The bones of the leg were much stockier (despite being longer), implying a more robust animal. The tail was held above the ground during normal locomotion. Like most sauropods, Apatosaurus had only a single large claw on each forelimb, with the first three toes on the hind limb possessing claws.
There are at least two species of Apatosaurus:
- A. ajax was discovered by Othniel Charles Marsh in 1877.
- A. louisae was discovered by William Holland in 1915.
- Another dinosaur species discovered in 1994 was at first named A. yahnahpin, but in 1998, it was renamed Eobrontosaurus yahnahpin.