They had teeth the size of bananas, were as long as buses and limousines, and hunted dinosaurs that ate near their waterways.
These are some of the results of a new study announced this week on a giant old animal called a “terrifying crocodile” or Deinosuchus.
The study published in the Journal of Vertebrate Paleontology found that the Deinosuchus, a line of giant crocodiles from North America, grew up to 30 meters long and was “the largest carnivore in its ecosystem” by 75 years in the Late Cretaceous Period, 82 million years ago.
Dr. Cossette of the New York Institute of Technology College of Osteopathic Medicine at Arkansas State University said large specimens were 30 to 35 feet long and weighed about 8,000 pounds. For comparison, he said that a large American alligator today is about 12 to 13 feet long, weighs about 700 to 800 pounds, and has teeth about three inches long at the tip of its snout.
He also said that the ancient reptiles had heads that were big enough and strong enough to hunt down dinosaurs that lived among them.
“Deinosuchus was a giant who must have terrorized dinosaurs who came to the water’s edge to drink, ”he said in a statement. “The entire animal was previously unknown. These new specimens we’ve examined reveal a bizarre, monstrous predator. “
In addition to killing dinosaurs, because of their size, the animals likely hunted almost anything that got in their way. The researchers found multiple bite marks on turtle shells and dinosaur bones.
They also found that at least three species of Deinosuchus roamed what is now the United States and Mexico. Two species lived in the west, from Montana to northern Mexico, and another species lived along the Atlantic coastal plain, from New Jersey to Mississippi.
The study said that despite the genus’ name, which means “terror crocodile,” the creatures were more closely related to alligators. But because of a “huge skull” they didn’t look like crocodiles or alligators.
The muzzle was long and wide, “but puffed up around the front of the nose in a way that no other living or extinct crocodile does,” the researchers said, using an alternate spelling for crocodile.
The reason for the enlarged nose is unknown, the researchers said. Nor do they know why the animal had two large holes at the tip of its snout in front of its nose.
“These holes are unique to Deinosuchus,” said Dr. Cossette. “Further research down the line will hopefully help us solve this mystery.”
His colleague on the study, Christopher Brochu, a vertebrate paleontologist at the University of Iowa, said the fossils showed that crocodiles “are not” living fossils “that have not changed since the age of the dinosaurs.”
“They have developed just as dynamically as any other group,” he said in the statement.
“The earliest ancestors of the American alligator like Deinosuchus were bizarre and unlike anything we see in modern crocodile species today,” said Dr. Cossette in the email. “The evolutionary history of Crocodylia is much more fascinating than you think.”
Mark A. Norell, curator and chairman of the paleontology division of the American Museum of Natural History, said the study had gained a lot of new knowledge, particularly about the strange inflation at the end of the skull, the weight and size of the animal, and the shape of its be Skull.
And Dr. Norell said there was much more to learn as the animal fossils remained rare, under-gathered, and under-discussed. “Usually their collection and investigation is an afterthought,” he said, “since most of the work on these formations and deposits is dominated by dinosaurs.”