A fearsome nine-foot-long crocodile that hunted by running on its hind legs was one of the world's top predators before the arrival of the dinosaurs. Carnufex carolinensis, which means 'Carolina Butcher' due to its ferocious appearance, was an early ancestor of modern crocodiles. Paleontologists believe it roamed the warm, wet rainforests of what is now North Carolina around 231 million years ago, preying upon small armoured reptiles and early mammals with its powerful jaws. Carnufex carolinensis, shown in the artists impression above, would have chased down prey on its hind legs and probably crunched its way though small armoured reptiles and early mammals with its long powerful jaws . Researchers discovered fossilised parts of the ferocious crocodilian's skull, spine and forelimbs in a rock formation in Chatham County, close to Sanford, North Carolina. Dr Lindsay Zanno, assistant research professor at North Carolina State University and director of the palaeontology lab at the North Carolina Museum of Natural Sciences, said the fossil could help provide new clues about the evolution of crocodiles. Name: Carnufex carolinensis . Meaning: Carolina Butcher. Carnufex is Latin for Butcher while Carolina refers to the state of North Carolina where the fossil was found. Age: The reptile lived 231 million years ago . Distinctive features: It had a long slender skull with a bony boss running from side to side. Its fore limbs were short and it probably ran on its larger hind limbs. Skeleton location: It was found in Chatham County, North Carolina. Importance: The fossil will help scientists unravel the evolution of early crocodiles. Running on its hind legs, Carnufex would have been the top predator in the area during the Triassic period. She said: '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. '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.' The scientists, whose work is published in the journal Scientific Reports, used high-resolution scanning techniques to reconstruct Carnufex's skull from the fossil fragments. They found that the skull was unexepectedly slender, at least 50cm in length, with an ornamented boss running across the top of the skull. They said that Carnufex is one of the world's earliest and largest early crocodile ancestors. Scientists reconstructed the skull of Carnufex carolinensis, shown above, using 3D scanning technology . At the time it was alive North Carolina was part of a super-continent called Pangea and was in the warm, wet equatorial region. Other large predators like rauisuchids and popsauroids, cousins of the ancient crocodiles, roamed much of the southern Hemisphere. They would have hunted alongside many of the early theropod dinosaurs that began to emerge at the same time. Carnufex was a large early crocodile and is marked in red above alongside other early crocodile species . Prehistoric crocodiles were able to run around like dogs to escape the jaws of predatory dinosaurs. This is according to a study published last year that showed, for the first time, how the reptiles evolved in a dinosaur dominated world. Today, most modern crocodiles live in freshwater habitats and feed on mammals and fish, but their ancestors ran around on land like dogs while others adapted to life in the open ocean, imitating the behaviour of whales. The study, by Bristol University, revealed how the jaws of the ancient crocodiles evolved to enable the fierce animals to survive in vastly different environments. The team examined variation in the shape and biomechanics function of the lower jaws in over 100 ancient crocodiles during the Mesozoic - a period which began 251 million years ago and covered over 170 million years. The study revealed that ancient crocodiles invaded the Jurassic seas and evolved jaws built primarily for water efficiency to capture agile prey, such as fish. Sample of jaws from the Mesozoic crocodile record . The research also found that variation peaked again in the Cretaceous period- 142 million years ago - where ancient crocodiles evolved a great variety of lower jaw shapes as they adapted to a diverse range of food. The research also found that variation peaked again in the Cretaceous period- 142 million years ago - where ancient crocodiles evolved a great variety of lower jaw shapes as they adapted to a diverse range of food. After the devastating end-Triassic extinction event, crocodile ancestors invaded the seas and evolved jaws primarily built to efficiently swim in the water to catch agile prey such as fish. They also evolved a great variety of lower jaw shapes during the Cretaceous Period - about 145 million to 65 million years ago - as they adapted to a diverse range of niches and environments alongside the dinosaurs, including eating plants. Surprisingly, the lower jaws of Cretaceous crocodiles did not have a huge amount of variation. Instead, the fossil record points towards novel adaptations in other areas of their anatomy, such as armadillo-like body armour. However, the dinosaurs did not come to dominate until 135 million years later when many of these large crocodylomorphs died out. The smaller ancestors of modern crocodiles, which looked more like modern day foxes but without fur, managed to survive. Dr Zanno said: 'The discovery of Carnufex, one of the world’s earliest and largest crocodylomorphs, adds new information to the push and pull of top terrestrial predators across Pangea. 'These animals hunted alongside the earliest theropod dinosaurs, creating a predator pile-up. Modern crocodiles like the Nile Crocodile pictured above are the descendants of the smaller and lighter crocodylomorphs that survived the extinctions at the end of the Triassic period and the rise of the dinosaurs . 'Theropods were ready understudies for vacant top predator niches when large-bodied crocs and their relatives bowed out. 'Predatory dinosaurs went on to fill these roles exclusively for the next 135 million years.' Susan Drymala, a palaeontologist at North Carolina State University who was also involved in the research, added: 'As theropod dinosaurs started to make it big, the ancestors of modern crocs initially took on a role similar to foxes or jackals, with small, sleek bodies and long limbs. 'If you want to picture these animals, just think of a modern day fox, but with alligator skin instead of fur.'
Carnufex carolinesis pursued reptiles and early mammals on its hind legs . Fragments of fossil skull, spine and forelimb were found in North Carolina . Scientists used 3D scanning to reconstruct the prehistoric predator's skull . Its name means Carolina Butcher due to the animal's fearsome appearance . Palaeontologists say it was probably the top predator in the Triassic Period . It lived around 231 million years ago, long before the dinosaurs dominated .