Cotyledion

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Cotyledion
Temporal range: Cambrian Stage 3
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Stem group: Entoprocta
Genus: Cotyledion
Luo et Hu, 1999
Species:
C. tylodes
Binomial name
Cotyledion tylodes
Luo et Hu, 1999

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]

See also

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References

  1. 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.
  2. McMenamin, M. A. S. (2013). "Breakthrough on the Cambrian Explosion". BioScience. 63 (10): 834–835. doi: 10.1525/bio.2013.63.10.14 .
  3. 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.
  4. McMenamin, M. A. S. (2013). "Breakthrough on the Cambrian Explosion". BioScience. 63 (10): 834–835. doi: 10.1525/bio.2013.63.10.14 .