Outline: a typical ornithopod
Acristavus
"crestless grandfather"
- Lived
- 84 to 72 million years ago, Late Cretaceous
- Diet
- Herbivore
- Group
- Ornithopods, Hadrosauridae
- Found in
- United States
- Named by
- Gates et al. 2011
Where its fossils were found
The evidence
Today
80 million years ago
Field notes
About Acristavus
What it was like
Acristavus was a duck-billed plant eater with no crest at all, unlike most of its relatives. It was related to Maiasaura and Brachylophosaurus, and it suggests that the early members of this group had plain heads.
Its world
It lived in the Late Cretaceous in what is now Montana and Utah. Its bones come from the Two Medicine and Wahweap formations. In Montana it shared the land with the tyrannosaur Daspletosaurus, and in Utah with the tyrannosaur Lythronax.
How it was found
Gates and colleagues named Acristavus in 2011. There are two recorded finds.
Lived alongside
Found in the same rock formations
Close relatives
Other members of Hadrosauridae
Sources: WikidataNamed in: T. A. Gates, J. R. Horner, and R. R. Hanna, C. R. Nelson. 2011. New unadorned hadrosaurine hadrosaurid (Dinosauria, Ornithopoda) from the Campanian of North America. Journal of Vertebrate Paleontology 31(4):798-811