Nav: Home

Study: Infamous 'death roll' almost universal among crocodile species

April 18, 2019

The iconic "death roll" of alligators and crocodiles may be more common among species than previously believed, according to a new study published in Ethology, Ecology & Evolution and coauthored by a researcher at the University of Tennessee, Knoxville.

Contrary to popular belief, crocodiles can't chew, so they use a powerful bite coupled with a full-bodied twisting motion--a death roll--to disable, kill, and dismember prey into smaller pieces. The lethal movement is characteristic of both alligators and crocodiles and has been featured in numerous movies and nature documentaries.

Until now, the death roll had only been documented in a few of the 25 living crocodilian species, but how many actually do it?

"We conducted tests in all 25 species, and 24 of them exhibited the behavior," said lead author Stephanie Drumheller-Horton, a paleontologist and adjunct assistant professor in the Department of Earth and Planetary Sciences at UT.

For the research, Drumheller-Horton teamed up with Kent Vliet from the University of Florida and Jim Darlington, curator of reptiles at the St. Augustine Alligator Farm.

It was previously believed that slender-snouted species, like the Indian gharial, didn't roll because their diets consist of small prey like fish, eaten whole.

But it turns out that feeding isn't the only time the animals might roll.

"Aggression between individual crocodylians can become quite intense, often involving bites and death rolls in establishing dominance or competition for females," Vliet said.

Paleosuchus palpebrosus, commonly called Cuvier's dwarf caiman, is the only species that did not perform a death roll under experimental conditions. "Although, it's also possible that they were just being uncooperative," said Darlington.

And the fossil ancestors of modern crocodiles? If they share a similar body plan and lifestyle with their modern counterparts, it's likely that they could death roll, too.

"Crocodile relatives have played the role of semi-aquatic ambush predator since the Age of Dinosaurs," said Drumheller-Horton.

Whether in the Northern Territories of Australia, a lake in the Serengeti, or a watering hole in the late Cretaceous, chances are that a patient predator is waiting in the water to surprise its next meal with a burst of speed, a powerful bite, and a spinning finish.
-end-
CONTACT:

Andrea Schneibel (865-974-3993, andrea.schneibel@utk.edu)

University of Tennessee at Knoxville

Related Crocodiles Articles:

What did ancient crocodiles eat? Study says as much as a snout can grab
To study the diet of ancient crocodiles, two researchers--one from the University of Tennessee, Knoxville, and one from Stony Brook University--combined mathematical analyses of the animals' shapes, surveys of modern crocodiles' diet, modeling methods for reconstructing the diet of fossil groups, and forensic-style interpretations of damaged bones from the distant past.
New species of crocodile discovered in museum collections
By looking at 90-year-old crocodile skulls in museum collections and double-checking with live specimens at a zoological park in Florida, researchers have just discovered a new species of ten-foot-long croc.
T. rex used a stiff skull to eat its prey
A Tyrannosaurus rex could bite hard enough to shatter the bones of its prey.
Mysterious Jurassic crocodile identified 250 years after fossil find
A prehistoric crocodile that lived around 180 million years ago has been identified -- almost 250 years after the discovery of it fossil remains.
No teeth cleaning needed: Crocodiles shed old teeth, grow new ones
Having one of the most powerful bites in the animal kingdom, crocodiles must be able to bite hard to eat their food such as turtles, wildebeest and other large prey.
Holy crocodiles
Sebastian Brackhane of the University of Freiburg has researched the cultural status of the reptiles in East Timor.
Some crocs of the past were plant eaters
Based on careful study of tooth remains, researchers have found that ancient groups of crocodyliforms -- the group including living and extinct relatives of crocodiles and alligators -- were not the carnivores we know today, as reported in the journal Current Biology on June 27, 2019.
Some extinct crocs were vegetarians
Based on careful study of fossilized teeth, scientists Keegan Melstom and Randall Irmis at the Natural History Museum of Utah at the University of Utah have found that multiple ancient groups of crocodyliforms -- the group including living and extinct relatives of crocodiles and alligators -- were not the carnivores we know today.
Study: Infamous 'death roll' almost universal among crocodile species
The iconic 'death roll' of alligators and crocodiles may be more common among species than previously believed, according to a new study published in Ethology, Ecology & Evolution and coauthored by a researcher at the University of Tennessee, Knoxville.
Jurassic crocodile discovery sheds light on reptiles' family tree
A 150 million-year-old fossil has been identified as a previously unseen species of ancient crocodile that developed a tail fin and paddle-like limbs for life in the sea.
More Crocodiles News and Crocodiles Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab