| 翻訳と辞書 |
Yunnanozoon
''Yunnanozoon lividum'' ("Livid Animal of Yunnan") is an extinct deuterostome suspected of being either a hemichordate〔Shu, D., Zhang, X. and Chen, L. 1996. Reinterpretation of Yunnanozoon as the earliest known hemichordate, ''Nature''. 380:428–430 (4 April 1996). () – accessed 3 December 2005〕 or chordate,〔 J. J. Sepkoski. 2002. A compendium of fossil marine animal genera. ''Bulletins of American Paleontology'' 363:1–560〕 from the Lower Cambrian, Chengjiang biota of Yunnan province, China.
''Yunnanozoon'' is similar to the form ''Haikouella'' which is almost certainly a chordate. Still, there are anatomical differences from ''Haikouella'', including a smaller stomach and much larger (1 mm) pharyngeal teeth. It is by no means certain whether Yunannozoon possessed features such as a heart, gills, etc., which are seen in well-preserved specimens of ''Haikouella''. ''Yunnanozoon'' somewhat resembles the Middle Cambrian ''Pikaia'' from the Burgess shale of British Columbia in Canada. Thirteen pairs of symmetrically arranged gonads have been identified, as have possible gill slits. However, some authors think that ''Yunnanozoon'' is closely related to the chordate ''Haikouella'' and that ''Yunnanozoon'' is probably a chordate rather than a hemichordate. A close relationship between ''Yunnanozoon'' and the taxon Vetulicolia has also been proposed.
==See also==
* Cristozoa
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「Yunnanozoon」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.
|
|