| Abydosaurus | |
|---|---|
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Clade: | †Sauropoda |
| Clade: | †Macronaria |
| Family: | †Brachiosauridae |
| Genus: | †Abydosaurus Chure et al., 2010 |
| Type species | |
| †Abydosaurus mcintoshi Chure et al.,2010 | |
Abydosaurus (meaning "Abydos lizard") is agenus ofbrachiosauridsauropoddinosaur known from skull andpostcranial material found in upperLower Cretaceous rocks of northeasternUtah, United States.
Abydosaurus is one of the few sauropods known from skull material, with the first described complete skull for a Cretaceous sauropod from the Americas.[1] It is also notable for its narrow teeth, as earlier brachiosaurids had broader teeth.[1]
Abydosaurus is based on theholotypeDINO 16488, a nearly complete skull and lower jaws with the first four neckvertebrae. Abundant skull and postcranial bones were found at the same site, including partial skulls from three additional individuals, a partialhip and associated tail vertebrae, ashoulder blade, anupper arm bone, andhand bones. These fossils were found in asandstone bed at the base of theMussentuchit Member of theCedar Mountain Formation, near the old visitor center ofDinosaur National Monument.Zircons from mudstones beneath the bone-bearing sandstone indicate the age of the sandstone and its contained bones is less than 104.46 ± 0.95 million years, in theAlbian stage of theEarly Cretaceous.[1]
Abydosaurus was named in 2010 by Daniel Chure and colleagues. The genus name is a reference toEgyptian mythology:Abydos is theGreek name for a city on theNile where the head and neck ofOsiris were buried, while the holotype ofAbydosaurus consists of a head and neck found in rocks overlooking theGreen River. Thetype species isA. mcintoshi in honor ofJohn S. ("Jack") McIntosh,[1] Professor of Physics, Emeritus,Wesleyan University, and his contributions to Dinosaur National Monument and the study of sauropod dinosaurs.[1][2][3]
AlthoughAbydosaurus lived some 50 million years afterGiraffatitan, the skulls of these two genera are similar except for the narrower, sharper teeth and smaller nose ofAbydosaurus.Abydosaurus can be differentiated from all other sauropods, includingGiraffatitan, by subtle features of thenasal andmaxillary bones, its relatively small external nares (nostrils), and some features of the teeth.[1] In 2012Thomas Holtz gave a length of 18.3 metres (60 ft).[4]
