9-Foot Crocodile Ancestor Dominated Before Dinosaurs

Scientists have just discovered a new 9-foot-long crocodilian ancestor that was once one of North America's top predators, dominating the Earth before dinosaurs came on the scene, new research indicates.

Unlike modern-day crocodiles, which waddle around on all fours and spend most of their time in the water, Carnufex carolinensis, or more menacingly known as the "Carolina Butcher," was a land-dwelling crocodylomorph that stomped around on its hind legs. Based on new fossils of its skull, spine and upper forelimb, researchers were able to determine that this carnivore likely preyed on smaller species such as armored reptiles and early mammal relatives.

The fragmented fossils were uncovered in North Carolina's Pekin Formation, which contains sediment deposits dating back 231 million years ago during the beginning of the Late Triassic period. This gives researchers a glimpse into what life during that time was like for Carnufex and other animals, when North Carolina was a wet, warm equatorial region starting to break apart from the supercontinent Pangea.

"Fossils from this time period are extremely important to scientists because they record the earliest appearance of crocodylomorphs and theropod dinosaurs, two groups that first evolved in the Triassic period, yet managed to survive to the present day in the form of crocodiles and birds," lead study author Lindsay Zanno, from North Carolina State University, said in a press release.

"The discovery of Carnufex," she added, "one of the world's earliest and largest crocodylomorphs, adds new information to the push and pull of top terrestrial predators across Pangea."

In order to better connect the piece of the puzzle (literally), Zanno and her colleagues scanned the individual bones of Carnufex's skull using a high-resolution surface scanner. Then they created a 3-D model of the reconstructed skull, using the more complete skulls of close relatives to fill in the blanks. (Scroll to read on...)

Believe it or not, Carnufex isn't the first crocodilian ancestor discovered by researchers. Nature World News reported back in January of a large reptile predator that also predated the dinosaurs, called Nundasuchus songeaensis. And while it did help to shed light on the evolutionary relationship between dinos and reptiles, this latest find helps to paint an even clearer picture.

According to the research team, predators such as large-bodied rauisuchids and poposauroids - fearsome cousins of ancient crocodiles that went extinct in the Triassic Period - hunted alongside early theropod dinosaurs in the Southern Hemisphere of Pangea.

However, the discovery of Carnufex indicates that in the north at least, large-bodied crocodylomorphs, not dinosaurs, were adding to the diversity of top predator niches.

"We knew that there were too many top performers on the proverbial stage in the Late Triassic," Zanno explained. "Yet, until we deciphered the story behind Carnufex, it wasn't clear that early crocodile ancestors were among those vying for top predator roles prior to the reign of dinosaurs in North America."

But their reign could not last forever. When the Triassic Period ended, large species like Carnufex disappeared while small-bodied crocodylomorphs and theropods survived, and the age of the dinosaurs began.

The findings are described in the journal Scientific Reports.

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