|
''Rajasaurus'' (meaning "king" or "king of lizards") is a genus of carnivorous abelisaurian theropod dinosaur with an unusual head crest. Between 1982 and 1984, its fossilized bones were discovered by Suresh Srivastava of the Geological Survey of India (GSI). Excavated from the Narmada River valley in Rahioli in the Kheda district of Gujarat, India, the find was announced as a new genus of dinosaur by American and Indian scientists on August 13, 2003. Paleontologists Paul Sereno of the University of Chicago, Jeff Wilson of the University of Michigan, and Srivastava worked together as an Indo–American group to study the Narmada River fossils.〔 The fossils represented the partial skeleton of the new species ''Rajasaurus narmadensis'', which means "princely lizard from the Narmada Valley."〔Wilson, J.A., Sereno, P.C., Srivastava, S., Bhatt, D.K., Khosla, A. and Sahni, A. (2003). ("A new abelisaurid (Dinosauria, Theropoda) from the Lameta Formation (Cretaceous, Maastrichtian) of India." ) (PDF) ''Contributions from the Museum of Paleontology (of Michigan )'', 31(1): 1-42.〕 The fossilized bones of ''Rajasaurus'' have also been found in the upriver region of the Narmada, at Jabalpur, in the state of Madhya Pradesh. ==Description== ''Rajasaurus'' was an abelisaurid, a member of a group of theropod predators known to have lived only on landmasses that were part of the supercontinent Gondwana, such as Africa, India, Madagascar, and South America. ''Rajasaurus'' closely resembles ''Majungasaurus'', a contemporary abelisaur from Madagascar, an island that had separated from the Indian landmass about 20 million years earlier. It was found to be an abelisaurid through a phylogenetic analysis of anatomical characteristics, and was described as a carnotaurine abelisaurid (the subfamily including ''Carnotaurus'') because of the configuration of its nasal bones and its possession of a growth ("excrescence") on its frontal bone. ''Rajasaurus'' is distinguished from other genera by its single nasal-frontal horn, the elongated proportions of its supratemporal fenestrae (holes in the upper rear of the skull), and the form of the ilia (principle bones of the hip) which feature a transverse ridge separating the brevis shelf from the hip joint.〔 ''Rajasaurus'' was identified from a partial skeleton including a part of the skull (braincase), backbone, hip bones, parts of the hind legs and tail. This specimen, GSI 21141/1–33, serves as the type specimen of the genus and species.〔 ''Rajasaurus'' measured about long and what is preserved of the skull shows it bore a distinctive low rounded horn,〔 made up of outgrowths from the nasal and frontal bones.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Rajasaurus」の詳細全文を読む スポンサード リンク
|