Cotyledion tylodes is an extinct, stalked filter-feeder known from the Chengjiang lagerstatten. The living animal reached a couple of centimetres in height, and bore a loose scleritome of ovoid sclerites. Its interpretation has been controversial, and it has been previously identified as a carpoid echinoderm,[1] or as a stem group echinoderm.[2] C. tylodes is now classified as a stem group entoprocta based on new fossils that clearly show a U-shaped gut and a crown of tentacles.[3] This entoproct interpretation of Cotyledion, however, has been questioned by Mark McMenamin, who considers it best interpreted as a stem group echinoderm based on the morphology of its stem sclerites.[4]
| Cotyledion Temporal range:
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|---|---|
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Stem group: | Entoprocta |
| Genus: | †Cotyledion Luo et Hu, 1999 |
| Species: | †C. tylodes
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| Binomial name | |
| †Cotyledion tylodes Luo et Hu, 1999
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See also
editReferences
edit- ^ Clausen, S. B.; Hou, X. G.; Bergström, J.; Franzén, C. (2010). "The absence of echinoderms from the Lower Cambrian Chengjiang fauna of China: Palaeoecological and palaeogeographical implications". Palaeogeography, Palaeoclimatology, Palaeoecology. 294 (3–4): 133–141. Bibcode:2010PPP...294..133C. doi:10.1016/j.palaeo.2010.01.001.
- ^ McMenamin, M. A. S. (2013). "Breakthrough on the Cambrian Explosion". BioScience. 63 (10): 834–835. doi:10.1525/bio.2013.63.10.14.
- ^ Zhang, Z.; Holmer, L. E.; Skovsted, C. B.; Brock, G. A.; Budd, G. E.; Fu, D.; Zhang, X.; Shu, D.; Han, J.; Liu, J.; Wang, H.; Butler, A. N.; Li, G. (2013). "A sclerite-bearing stem group entoproct from the early Cambrian and its implications". Scientific Reports. 3: 1066. Bibcode:2013NatSR...3E1066Z. doi:10.1038/srep01066. PMC 3548229. PMID 23336066.
- ^ McMenamin, M. A. S. (2013). "Breakthrough on the Cambrian Explosion". BioScience. 63 (10): 834–835. doi:10.1525/bio.2013.63.10.14.
