Deinosuchus lived during the late Cretaceous period, from 82 million years to 73 million years ago. This monster croc, whose habitat consisted of areas in North America from Montana to northern Mexico and New Jersey to Mississippi, would have seen a world that looked much different than it does today. 

At the time, the continent was much warmer, with a coastal, tropical, and subtropical climate similar to Florida or Georgia. And although Deinosuchus lived in freshwater, it could also be found in brackish waters. At the time, the continent was cut into two by the Western Interior Seaway, also known as the Cretaceous Seaway, that stretched from the Hudson Bay down to the Gulf of Mexico. 

An Apex Predator Amongst Apex Predators

Nicknamed Hell’s Aquarium for the number of carnivorous sea monsters that inhabited this swath of sea, Deinosuchus lived along with a number of toothy beasts. It would have been among the larger of the apex predators living in North America at the time, at around 36 feet or about the length of a school bus. However, it’s worth noting that the East Coast species were a little smaller, and the females were smaller than the males. 

Its teeth rival those of a Tyrannosaurus rex (though it did not exist at the same time), says Scott Persons, an assistant professor of paleontology at the College of Charleston. The teeth aren’t as long as T. rex, but they were thick and coupled with a killer bite force, a frightening combination.

“A big gator (even today) can crush the shell of a turtle,” says Persons.

Depending on where it called home, it lived among a variety of duck-billed dinosaurs, Ceratopsian (horned) dinosaurs, Ankylosaurus, and various theropods, says Christopher Brochu, a vertebrate paleontologist and expert in crocodyliformes at The University of Iowa. 

Read More: 5 Of The Biggest Animals To Ever Live On Earth

A Large Fossil Record

Most crocodilians, Deinosuchus included, are not diet-restrictive, which means they eat whatever they can fit down their gullet. Deinosuchus would have killed and also scavenged any number of beasts, but like crocodiles today, they would be unlikely to attempt to take down an animal that was a whole lot bigger than them because it would be hard to swallow.

Additionally, the neat thing about Deinosuchus is that we can learn about what it ate from its coprolite — fossilized poop — that shows it largely ate its prey whole.

“They left behind a great fossil record and preservation potential because their poop had a lot of bone incorporated into it,” says Persons.

Not to mention that they shed teeth throughout their lives, and each tooth was sturdy and coated with enamel, which meant it would preserve well. Persons says that we also have a lot of its osteoderms, the armor that lines its back and protects it from predators, similar to the osteoderms found on alligators and crocodiles today. 

From these fossils, we know that Deinosuchus would have taken a long time to reach adulthood, up to 35 years, and at that time, it could have been vulnerable to other carnivorous species like the T. rex.

“Anything bigger than them would have been a threat,” says Brochu.

It’s unclear why Deinosuchus eventually went extinct. But it was not around at the beginning of the end-Cretaceous extinction event, which means an asteroid didn’t cause its end. Today, Brochu says there’s no modern analog to the species, though both Brochu and Persons agree that it’s more closely related to a modern alligator than a crocodile. Either way, it was a killer beast in its day.

Read More: These Extinct Giant Crocs May Have Hunted Our Ancient Ancestors

Article Sources

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Sara Novak is a science journalist based in South Carolina. In addition to writing for Discover, her work appears in Scientific American, Popular Science, New Scientist, Sierra Magazine, Astronomy Magazine, and many more. She graduated with a bachelor’s degree in Journalism from the Grady School of Journalism at the University of Georgia. She’s also a candidate for a master’s degree in science writing from Johns Hopkins University, (expected graduation 2023).