Shankouclavais an extinct genus oftunicates.It represents the oldest candidate member of this group, dating to518million years ago.It has been found in theLower CambrianMaotianshan Shaleat Shankou village,Anning,nearKunming(South China). Each of the eight specimens found and used for description were isolated, suggesting that the genus wassolitaryand notcolonial.[2]
| Shankouclava Temporal range:Cambrian Stage 3,
| |
|---|---|
| |
| Restoration ofS. anningense. | |
Scientific classification
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Subphylum: | Tunicata |
| Genus: | †Shankouclava Chen et al., 2003 |
| Type species | |
| †Shankouclava anningense Chen et al., 2003
| |
| Species | |
| |
Morphology
editShankouclavahad a soft, sac-like body that was elongated and pointed proximally. The body lengths of individuals vary from 2 cm (0.8 in) to 4 cm (1.6 in).[2]
Degan Shu asserts that some fossil specimens exhibit tentacles, which would make the genus similar to thedeuterostomePhlogites.[3]Expanding on this idea, Shu and colleagues argue against atunicateaffinity forShankouclava.[4]
Etymology
editThe generic name is composed of the fossil locality, Shankou, and theLatinwordclava(club-shaped).[2]
Classification
editA stem group tunicate affinity forShankouclavahas been broadly accepted, though some authors have expressed reservations that the evidence in favour of this affinity is not conclusive.[5]
Another Cambrian tunicate,Megasiphon,known from a single specimen, resembles more closely the morphology of surviving tunicates.[6]
References
edit- ^Yang, C.; Li, X.-H.; Zhu, M.; Condon, D. J.; Chen, J. (2018)."Geochronological constraint on the Cambrian Cheng gian g biota, South China"(PDF).Journal of the Geological Society.175(4): 659–666.Bibcode:2018JGSoc.175..659Y.doi:10.1144/jgs2017-103.ISSN0016-7649.S2CID135091168.
- ^abcChen, Jun-Yuan; Huang, Di-Ying; Peng, Qing-Qing; Chi, Hui-Mei; Wang, Xiu-Qiang; Feng, Man (2003)."The first tunicate from the Early Cambrian of South China".Proceedings of the National Academy of Sciences.100(14): 8314–8318.Bibcode:2003PNAS..100.8314C.doi:10.1073/pnas.1431177100.PMC166226.PMID12835415.
- ^Shu (2008)."Cambrian explosion: Birth of tree of animals".Gondwana Research.14(1–2): 219–240.Bibcode:2008GondR..14..219S.doi:10.1016/j.gr.2007.08.004.
- ^Shu, D.-G.; Conway Morris, S.; Zhang, Z.-F.; Han, J. (2010)."The earliest history of the deuterostomes: The importance of the Cheng gian g Fossil-Lagerstätte".Proceedings of the Royal Society B: Biological Sciences.277(1679): 165–174.doi:10.1098/rspb.2009.0646.PMC2842668.PMID19439437.
- ^Conway Morris (29 June 2006)."Darwin's dilemma: the realities of the Cambrian 'explosion'".Philos Trans R Soc Lond B Biol Sci.361(1470): 1069–1083.doi:10.1098/rstb.2006.1846.PMC1578734.PMID16754615.
- ^Nanglu, Karma; Lerosey-Aubril, Rudy; Weaver, James C.; Ortega-Hernández, Javier (2023)."A mid-Cambrian tunicate and the deep origin of the ascidiacean body plan".Nature Communications.14(1): 3832.doi:10.1038/s41467-023-39012-4.PMC10325964.PMID37414759.
 | This tunicate-related article is astub.You can help Wikipedia byexpanding it. |
 | Thisprehistoric animalarticle is astub.You can help Wikipedia byexpanding it. |