When it came time to name the previously unknown prehistoric crocodile whose bones were found in Chatham County several years ago, paleontologist Lindsay Zanno went with something decidedly unsubtle.
She chose Carnufex carolinesis, Latin for “Carolina butcher.”
“I thought it had a nice ring,” said Zanno, a research professor at N.C. State University who also runs the paleontology and geology lab at the N.C. Museum of Natural Sciences. “When I saw this animal, and when we reconstructed its skull, it was clearly an animal built for slicing flesh.”
The discovery of the Carolina butcher was announced Thursday in a paper in the journal Scientific Reports and with a public presentation at the science museum in downtown Raleigh starting at 11 a.m.
The presentation includes an artist’s rendering of what the creature might have looked like, based on the few bones that were found and what’s known about its closest relatives.
This specimen was about 9 feet long and was probably a top predator, feasting on armored reptiles and early mammals found at the time, about 231 million years ago. This is the beginning of what’s known as the late Triassic Period, when what is now Chatham County was near the equator in a warm, humid environment of ferns and conifers.
Scientists know the age of the creature not from its bones but from the age of the rocks in which it was found, in a quarry more than a decade ago.
‘Bits and pieces’
Museum curator Vincent Schneider found the bones mostly encased in rock and brought them back to the museum, where they remained a mystery for years.
“You could only see bits and pieces of the bones,” Zanno said. “Researchers had come to look at it, but nobody had really been sure what this animal was.”
That changed after Zanno came to the museum in 2012 and after one of her graduate students who was studying Triassic animals, Susan Drymala, got interested in the bones.
When they took the rock apart, they found parts of a skull, spine and upper forelimb of what’s known as a crocodylomorph, the ancestors of today’s crocodiles. The anatomy was different from known crocodylomorphs from the time and it was three to four times larger, Zanno said.
Zanno said Carnufex appears to be a missing link between creatures that stood on their hind legs and had skulls that resembled a Tyrannosaurus rex and later ones that moved around on all fours, like present-day crocs and alligators.
‘Walking on 2 legs’
Scientists won’t know for sure until someone finds Carnufex’s hind limbs, but the animal’s small forelimbs suggest that it walked on its hind legs, Zanno said.
“We decided to learn toward walking on two legs, instead of walking on both front and back,” she said. “But we don’t have enough of the skeleton to say for sure either way.”
The Carolina butcher is the second new ancient crocodile ancestor found near Raleigh and identified at the science museum in as many months. Last month, Appalachian State University geology professor Andrew B. Heckert announced the discovery of a new kind of aetosaur from the late Triassic Period with a distinctive ring of armor plates around its neck.
The fossilized bones had been encapsulated in Triassic rock removed from one of the region’s clay mines which, Heckert said, provide a steady supply of new fossils to discover.
The Triassic Period took place 248 million to about 200 million years ago. It followed a mysterious mass extinction that left the Earth relatively open to new creatures and is a time when early mammals, dinosaurs, turtles, birds, crocodiles and lizards began to appear. The period ended with another mass extinction and the emergence of better-adapted dinosaurs which dominated the Jurassic Period.