It was another time. At the end of the Cretaceous period, North America split in two by a giant inland sea. Dinosaurs, near the end of their reign, were still numerous in this hot and humid place. But they had to watch their step, especially from the water’s edge.
In the shallow drowsiness Deinosuchus: ‘crocodile of terror’. This extinct giant crocodile was the largest carnivore in its semi-aquatic environment – a powerful roof predator, which would also be celebrated with dinosaurs if they moved too close.
Deinosuchus fossils were first found in the US in the 1850s and have been studied for more than a century, but classifications of species within the genus have long been debated.
In a new study, researchers from the University of Iowa reviewed existing fossil evidence, and also looked at newly collected fossil specimens.
The results of their phylogenetic reassessment suggest three distinct types of Deinosuchus can be distinguished in the fossil record: species of the suggested type D. riograndensis, D. hatcheri, and a newly identified species, D. schwimmeri.
“Deinosuchus “It’s a giant that must have terrorized the dinosaurs that came to the water’s edge to drink,” said lead researcher and paleontologist Adam Cossette, now with the New York Institute of Technology.
“Until now, the whole animal was unknown. These young specimens we examined reveal a strange, monstrous, toothed banana-sized predator.”
While the oldest known Deinosuchus the specimen so far is roughly 82 million years old, researchers say a common ancestral population for all the different species is likely, and would have existed in North America before rising seas led to the Inland Sea Western cutting the continent in half.
When this happened, the researcher speculates that different environments on the east and west coasts led to evolutionary adaptations that resulted in slightly different morphologies and body sizes of D. riograndensis, D. hatcheri, and D. schwimmeri.
“It was a strange animal,” says paleonologist Christopher Brochu. “This shows that crocodiles are not ‘living fossils’ that have not changed since the age of the dinosaurs. They have evolved just as dynamically as any other group.”
Based on fossil evidence, D. riograndensis and D. hatcheri spent their dinosaur hunting days in western North America, from Montana to northern Mexico. D. schwimmeri, meanwhile, lived along the Atlantic coast, between New Jersey and Mississippi.
Despite their coastal affiliation, however, these giant creatures – which ranged up to 10 meters (33 ft) in length – were some of the largest and most fearsome crocodiles ever, and were closer in appearance to alligators. today than crocodiles.
“At the time he was living here in the eastern US, there was nothing bigger,” Columbus State University geologist and paleontologist David Schwimmer told Ledger-Enquirer.
Schwimmer was not involved with the new study, but was the inspiration for the appointment of D. schwimmeri, given his contributions to the field.
“We actually have bite marks from these people on dinosaur bones. Now, the only question you can ask: Were they predators or predators?” Tha Schwimmer.
“My guess is predatory … This creature was big enough to exterminate most dinosaurs. Also, quite interestingly, most of the bites we see are on the bones of the legs and tailbones. If you’re going to grab a dinosaur, this is it.” the place where you are “you will catch them”.
Findings are reported in Journal of Paleontology Vertebrate.