Fearsome croc called the Carolina Butcher once ruled the north

Fossil find pegs giant, bipedal reptile as a top predator 230 million years ago

croc fossil

WHAT A CROC  Carnufex carolinensis, shown in this artist’s illustration, looked a lot like living crocodiles, but it walked on two legs, not four.

© Jorge Gonzales

Before dinosaurs ruled what is now North America, the Carolina Butcher topped the predator charts. 

A reconstruction of this newly identified species suggests that Carnufex carolinensis was 3 meters long and looked a lot like living crocodiles — except it walked on two legs, not four. Researchers led by North Carolina Museum of Natural Sciences paleontologist Lindsay Zanno found its fossilized skull, spine and arm bones in 231-million-year-old rock deposits in central North Carolina.

C. carolinensis is one of the oldest and largest crocodile ancestors identified to date. Its size and stature also suggest that for a time, it was one of the top predators in the part of the supercontinent Pangaea that became North America, Zanno and colleagues write March 19 in Scientific Reports.

SLEEK AND SLENDER Reconstructing Carnufex carolinensis based on its bones suggests that its skull was longer than 50 centimeters and its body was roughly 3 meters from head to tail. L. Zanno/NCMNS

Past fossil finds show that cousins of ancient crocodiles were vying with the earliest bipedal dinosaurs, called theropods, for the title of top predator in the southern regions of Pangaea.

C. carolinensis and others like it may have dominated the northern regions of Pangaea without competition from early dinosaurs, the researchers write.

The researchers note that its reign probably ended 201 million years ago. That’s when a mass extinction event wiped out most large, land-based predators, clearing the way for dinosaurs to fully dominate during the Jurassic period.

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

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