研究人员发现猛龙新品种迅
A new species of dinosaur, a relative of the famous Velociraptor(迅猛龙) , has been discovered in Inner Mongolia by two PhD students. The exceptionally well preserved(保藏的,腌制的) dinosaur, named Linheraptor exquisitus, is the first near complete skeleton of its kind to be found in the Gobi desert since 1972, and will help scientists work out the appearance of other closely related dinosaur species.
Linheraptor is in the Dromaeosauridae family of the carnivorous(食肉的) theropod(兽脚亚目的) dinosaurs and lived during the Late Cretaceous(白垩纪) period. In addition to Linheraptor and Velociraptor, theropod dinosaurs include charismatic(神赐能力的,超凡魅力的) meat-eaters like Tyrannosaurus rex(雷克斯霸王龙) and modern birds.
The two PhD students, Michael Pittman from UCL (University College London) and Jonah Choiniere from George Washington University (GWU), found the dinosaur sticking out of a cliff face during a field project in Inner Mongolia, China. Their research is published online today in the journal Zootaxa.
"Jonah saw a claw protruding(伸出,突出) from the cliff face. He carefully removed it and handed it to me. We went through its features silently but he wanted my identification first. I told him it was from a carnivorous dinosaur and when he agreed I'm surprised nobody in London heard us shouting," said Michael Pittman, a PhD student in the UCL Department of Earth Sciences who was the co-discoverer of the dinosaur.
"I've always wanted to discover a dinosaur since I was a kid, and I've never given up on the idea. It was amazing that my first discovery was from a Velociraptor relative. My thesis is on the evolution and biomechanics of dinosaur tails but the carnivorous dinosaurs are my favourite and my specialty," he added.
At approximately 2.5 metres long and 25 kilograms, the researchers believe Linheraptor would have been a fast, agile(敏捷的,灵活的) predator that preyed on small horned dinosaurs(三角龙) related to Triceratops(三角龙) . Like other dromaeosaurids(奔龙) , it possessed a large "killing claw" on the foot, which may have been used to capture prey. Within the Dromaeosauridae family, Linheraptor is most closely related to another recently discovered species Tsaagan mangas.
Linheraptor differs from all other dromaeosaurs(驰龙科) because of a triangular hole in front of the eye socket(眼窝,眼眶) called the antorbital fenestra(眶前孔) , which is a space in the skull that sinuses(鼻窦) would have occupied. In Linheraptor this triangular hole is divided into two cavities – one of which is particularly big.
"This is a really beautiful fossil and it documents a transitional(过渡期的) stage in dromaeosaurid evolution," said Dr. Xu Xing, Professor of Palaeontology at the Institute of Vertebrate Paleontology & Paleoanthropology (IVPP).
Linheraptor was found in rocks of the Wulansuhai Formation, part of a group of red sandstone rocks found in Inner Mongolia, China during a field expedition by the researchers in 2008. It is the fifth dromaeosaurid discovered in these rocks, which are famous for their preservation of uncrushed, complete skeletons.
The research was done as part of the Inner Mongolia Research project, led by Dr. Xu, which aims to better understand the Late Cretaceous ecosystem of Inner Mongolia, China which is analogous(类似的) but less well-studied than the well known Late Cretaceous ecosytem of Outer Mongolia. The research was funded by the Geological Society of London, the US National Science Foundation, the Chinese National Science Foundation, and George Washington University.