Yunnanozoon
| Yunnanozoon Temporal range: Early Cambrian |
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| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata? |
| Genus: | Yunnanozoon |
| Binomial name | |
| Yunnanozoon lividum Chen et al., 1995 |
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Yunnanozoon lividum ("Livid Animal of Yunnan") is a suspected a hemichordate[1] or chordate[2] from the Lower Cambrian, Chengjiang biota of Yunnan province, China.
Yunnanozoon is similar to the form Haikouella[3] which is almost certainly a chordate. Still, there are anatomical differences from Haikouella, including a smaller stomach and much larger (1 mm) pharyngeal teeth. Yunannozoon is not known for sure to possess many features like heart, gills, etc. that are known from 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 phylum Vetulicolia has also been proposed.
[edit] See also
[edit] References
- ^ Shu, D., Zhang, X. and Chen, L. 1996. Reinterpretation of Yunnanozoon as the earliest known hemichordate, Nature. 380:428-430 (4 April 1996). [1] - accessed December 3, 2005
- ^ J. J. Sepkoski. 2002. A compendium of fossil marine animal genera. Bulletins of American Paleontology 363:1-560
- ^ Chen (2009). "The sudden appearance of diverse animal body plansduring the Cambrian explosion". The International journal of developmental biology 53 (5–6): 733–751. doi:10.1387/ijdb.072513cj. PMID 19557680.
[edit] External links
- A picture can be found at http://www.gs-rc.org/repo/repoe.htm
