| 翻訳と辞書 |
| Bharattherium ： ウィキペディア英語版 |
Bharattherium
''Bharattherium'' is a mammal that lived in India during the Maastrichtian (latest Cretaceous). The genus has a single species, ''Bharattherium bonapartei''. It is part of the gondwanathere family Sudamericidae, which is also found in Madagascar and South America during the latest Cretaceous. The first fossil of ''Bharattherium'' was discovered in 1989 and published in 1997, but the animal was not named until 2007, when two teams independently named the animal ''Bharattherium bonapartei'' and ''Dakshina jederi''. The latter name is now a synonym. ''Bharattherium'' is known from a total of eight isolated fossil teeth, including one incisor and seven molariforms (molar-like teeth, either premolars or true molars).
''Bharattherium'' molariforms are high, curved teeth, with a height of . In a number of teeth tentatively identified as fourth lower molariforms (mf4), there is a large furrow on one side and a deep cavity (infundibulum) in the middle of the tooth. Another tooth, perhaps a third lower molariform, has two furrows on one side and three infundibula on the other. The tooth enamel has traits that have been interpreted as protecting against cracks in the teeth. The hypsodont (high-crowned) teeth of sudamericids like ''Bharattherium'' are reminiscent of later grazing mammals, and the discovery of grass in Indian fossil sites contemporaneous with those yielding ''Bharattherium'' suggest that sudamericids were indeed grazers.
==Taxonomy==
A gondwanathere tooth, catalogued as VPL/JU/NKIM/25, was first discovered in the Maastrichtian (latest Cretaceous, about 70–66 million years ago) Intertrappean Beds of Naskal, India, in 1989, but it was not identified as such until another gondwanathere, ''Lavanify'', was found on Madagascar in the middle 1990s. The discoveries of ''Lavanify'' and VPL/JU/NKIM/25 were announced in ''Nature'' in 1997. Gondwanatheres were previously known only from Argentina; these discoveries extended the range of the gondwanathere family Sudamericidae across the continents of the ancient supercontinent of Gondwana.
In 2007, two teams of scientists independently named the Indian gondwanathere on the basis of new material; both teams included VPL/JU/NKIM/25 in their newly named species. Guntupalli Prasad and colleagues named the animal ''Bharattherium bonapartei'' on the basis of an additional tooth, VPL/JU/IM/33, from another Intertrappean locality, Kisalpuri. The generic name, ''Bharattherium'', combines ''Bharat'', Sanskrit for "India", with the Ancient Greek ''therion'', meaning "beast", and the specific name, ''bonapartei'', honors Argentine paleontologist José Bonaparte, who was the first to describe a gondwanathere fossil. G.P. Wilson and colleagues named ''Dakshina jederi'' on the basis of six teeth (in addition to VPL/JU/NKIM 25), and identified some additional material as indeterminate gondwanatheres. Of these teeth, three (GSI/SR/PAL-G059, G070, and G074) are from a third Intertrappean site at Gokak and three (GSI/SR/PAL-N071, N210, and N212) are from Naskal. ''Dakshina'', the generic name, derives from Sanskrit ''daakshinaatya'' "of the south", and refers both to the animal's occurrence in southern India and to the distribution of gondwanatheres in the southern continents. The specific name, ''jederi'', honors University of Michigan paleontologist Jeffrey A. Wilson, nicknamed "Jeder", who played an important role in the project that led to the discovery of ''Dakshina''. Wilson and colleagues also described three other gondwanathere teeth from Gokak (GSI/SR/PAL-G111, G112, and G211), which they tentatively identified as a different species of gondwanathere on their small size. In 2008, Prasad commented that ''Bharattherium bonapartei'' and ''Dakshina jederi'' represented the same species and that ''Bharattherium'', which was published first, was the correct name.
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「Bharattherium」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|