A newly discovered crocodilian ancestor may have filled one of North Americas top predator1 roles before dinosaurs2 arrived on the continent. Carnufex carolinensis, or the “Carolina Butcher,“ was a 9-foot long, land-dwelling crocodylomorph that walked on its hind3 legs and likely preyed4 upon smaller inhabitants of North Carolina ecosystems5 such as armored reptiles6 and early mammal relatives. Paleontologists from North Carolina State University and the North Carolina Museum of Natural Sciences recovered parts of Carnufexs skull7, spine8 and upper forelimb from the Pekin Formation in Chatham County, North Carolina. Because the skull of Carnufex was preserved in pieces, it was difficult to visualize9 what the complete skull would have looked like in life. To get a fuller picture of Carnufexs skull the researchers scanned the individual bones with the latest imaging technology - a high-resolution surface scanner. Then they created a three-dimensional model of the reconstructed skull, using the more complete skulls10 of close relatives to fill in the missing pieces.The Pekin Formation contains sediments11 deposited 231 million years ago in the beginning of the Late Triassic (the Carnian), when what is now North Carolina was a wet, warm equatorial region beginning 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,“ says Lindsay Zanno, assistant research professor at NC State, director of the Paleontology and Geology lab at the museum, and lead author of a paper describing the find. “The discovery of Carnufex, one of the worlds earliest and largest crocodylomorphs, adds new information to the push and pull of top terrestrial predators12 across Pangea.“Typical predators roaming Pangea included large-bodied rauisuchids and poposauroids, fearsome cousins of ancient crocodiles that went extinct in the Triassic Period. In the Southern Hemisphere, “these animals hunted alongside the earliest theropod dinosaurs, creating a predator pile-up,“ says Zanno. However, the discovery of Carnufex indicates that in the north, large-bodied crocodylomorphs, not dinosaurs, were adding to the diversity of top predator niches13. “We knew that there were too many top performers on the proverbial stage in the Late Triassic,“ Zanno adds. “Yet, until we deciphered the story behind Carnufex, it wasnt clear that early crocodile ancestors were among those vying14 for top predator roles prior to the reign15 of dinosaurs in North America.“词汇解析：1 predator n.捕食其它动物的动物；捕食者参考例句：The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。2 dinosaurs n.恐龙( dinosaur 的名词复数 )；守旧落伍的人，过时落后的东西参考例句：The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自简明英汉词典Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自简明英汉词典3 hind adj.后面的，后部的参考例句：The animal is able to stand up on its hind limbs.这种动物能够用后肢站立。Dont hind her in her studies.不要在学业上扯她后腿。4 preyed v.掠食( prey 的过去式和过去分词 )；掠食；折磨；（人）靠欺诈为生参考例句：Remorse preyed upon his mind. 悔恨使他内心痛苦。 来自现代英汉综合大词典He had been unwise and it preyed on his conscience. 他做得不太明智，这一直让他良心不安。 来自辞典例句5 ecosystems n.生态系统( ecosystem 的名词复数 )参考例句：There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自简明英汉词典Madagascars ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样，从雨林到半荒漠等不一而足。 来自辞典例句6 reptiles n.爬行动物，爬虫( reptile 的名词复数 )参考例句：Snakes and crocodiles are both reptiles. 蛇和鳄鱼都是爬行动物。 来自简明英汉词典Birds, reptiles and insects come from eggs. 鸟类、爬虫及昆虫是卵生的。 来自现代汉英综合大词典7 skull n.头骨；颅骨参考例句：The skull bones fuse between the ages of fifteen and twenty-five.头骨在 15 至 25 岁之间长合。He fell out of the window and cracked his skull.他从窗子摔了出去，跌裂了颅骨。8 spine n.脊柱，脊椎；(动植物的)刺；书脊参考例句：He broke his spine in a fall from a horse.他从马上跌下摔断了脊梁骨。His spine developed a slight curve.他的脊柱有点弯曲。9 visualize vt.使看得见，使具体化，想象，设想参考例句：I remember meeting the man before but I cant visualize him.我记得以前见过那个人，但他的样子我想不起来了。She couldnt visualize flying through space.她无法想像在太空中飞行的景象。10 skulls 颅骨( skull 的名词复数 )； 脑袋； 脑子； 脑瓜参考例句：One of the womens skulls found exceeds in capacity that of the average man of today. 现已发现的女性颅骨中，其中有一个的脑容量超过了今天的普通男子。We could make a whole plain white with skulls in the moonlight! 我们便能令月光下的平原变白，遍布白色的骷髅！11 sediments 沉淀物( sediment 的名词复数 )； 沉积物参考例句：When deposited, 70-80% of the volume of muddy sediments may be water. 泥质沉积物沉积后，体积的 70-80是水。Oligocene erosion had truncated the sediments draped over the dome. 覆盖于穹丘上的沉积岩为渐新世侵蚀所截削。12 predators n.食肉动物( predator 的名词复数 )；奴役他人者（尤指在财务或性关系方面）参考例句：birds and their earthbound