|
''Chelodina'', collectively known as ''snake-necked turtles'', is a large and diverse genus of long-necked Chelid turtles with a complicated nomenclatural history.〔 Although in the past ''Macrochelodina'' and ''Macrodiremys'' have been considered separate genera and prior to that all the same, they are now considered subgenera of the ''Chelodina''.〔 ''Chelodina'' is an ancient group of Chelid turtles native to Australia, New Guinea, the Indonesian Rote Island, and East Timor. The turtles within this subgenus are small to medium-sized, with oval shaped carapace. They are side-necked turtles, meaning they tuck their head partially around the side of their body when threatened instead of directly backwards. ''Macrochelodina'' represents those species that have often been termed the ''Chelodina'' B group, or thick necked snake neck turtles. The subgenus was described in 1985 by Wells & Wellington (as a new genus) but was not recognized until recently when it was shown that the name was valid. As such they are a side-neck turtle of the family Chelidae with extremely long necks and long flattened heads. They are specialist fish eaters using a strike and gape mode of feeding. They are medium to large species with the largest ''Chelodina (M.) expansa'' reaching shell lengths of some .〔(Macrochelodina expansa (Grey, 1856) - Broad-Shelled Turtle )〕 The first fossils (''C. (M.) alanrixi'') are known from Queensland from the Eocene period (Lapparent de Broin, F. de, & Molnar, R. E., 2001).〔Lapparent de Broin, F. de, & Molnar, R. E., 2001: Eocene chelid turtles from Redbank Plains, Southeast Queensland, Australia. ''Geodiversitas'': Vol. 23, #1, pp. 41-79〕 ''Macrodiremys'' is a monotypic genus recently split off from the rest of the ''Chelodina''.〔 Its sole member is the enigmatic ''Chelodina (Macrodiremys) colliei'' from Western Australia. ==Taxonomy== Current taxonomy follows that of Georges & Thomson, 2010〔Georges, A. & Thomson, S. 2010. Diversity of Australasian freshwater turtles, with an annotated synonymy and keys to species. Zootaxa 2496: 1–37.〕 with updates from van Dijk et al. 2014.〔Turtle Taxonomy Working Group (Dijk, P.P., Iverson, J.B., Rhodin, A.G.J., Shaffer, H.B., and Bour, R. ). 2014. Turtles of the world, 7th edition: annotated checklist of taxonomy, synonymy, distribution with maps, and conservation status. In: Rhodin, A.G.J., Pritchard, P.C.H., van Dijk, P.P., Saumure, R.A., Buhlmann, K.A., Iverson, J.B., and Mittermeier, R.A. (Eds.). Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group. (Chelonian Research Monographs 5(7):000.329–479 ), doi:10.3854/ crm.5.000.checklist.v7.2014.〕 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「Chelodina」の詳細全文を読む スポンサード リンク
|