Hypacrosaur Toe Fossil 
Age: 80 - 74 Million Years Old
Cretaceous Era
Species: Hypacrosaur
Specimen: Phalanges
Discovered: Montana, Two River Formation
 
- Hypacrosaur
Hypacrosaurus was a genus of duckbill dinosaur similar in appearance to Corythosaurus. Like Corythosaurus, it had a tall, hollow rounded crest, although not as large and straight. It is known from the remains of two species that spanned 75 to 67 million years ago, in the Late Cretaceous of Alberta, Canada, and Montana, United States, and is the latest hollow-crested duckbill known from good remains in North America. It was an obscure genus until the discovery in the 1990s of nests, eggs, and hatchlings belonging to H. stebingeri.