Fall 2013: Highway Interchange Bridge Work
Painted Desert Traffic Interchange (I-40 Exit 311) may be closed for construction. Check here for updates from Arizona Department of Transportation (ADOT): More »
Nov. 2012-July 2013, due to bank error credit cards may not have been charged for your entrance fee
...due to a bank error credit cards may not have been charged for your entrance fee, even if you received a receipt from the entrance station. The error was corrected on Sept. 26th, 2013. We apologize for any inconvenience this may have caused.
Reptiles of the Late Triassic
Archosaurian reptiles were the predominant faunal element in the Late Triassic of Northern Arizona representing the majority of terrestrial carnivores and herbivores. The archosaurs or "ruling reptiles," consist of the dinosaurs, crocodiles, birds, and Triassic crocodile-like forms such as aetosaurs, phytosaurs, rauisuchians, and crocodylomorphs. Except for modern birds and crocodiles, all of these forms are now extinct. However, because of recent findings of dinosaurs with feathers in China and other similarities between the two groups, many paleontologists now consider birds a modern form of dinosaur.
The crocodylomorphs are distant ancestors of today's crocodiles. Interestingly these were very small, gracile carnivores that were completely terrestrial in nature. The most common crocodylomorph found in the park is the "sphenosuchian" Hesperosuchus.
Petrified Forest National Park Triassic Reptiles Taxa List
Acaenosuchus geoffreyi (Stagonolepididae)
Did You Know?
Petrified Forest National Park is the only national park unit to protect a section of Historic Route 66!