Petalilium

Petalilium latus
Temporal range: Cambrian Stage 3
A reconstruction of the closely related species Nectocaris pteryx. Petalilium was larger in size, but otherwise comparable to Nectocaris.
Scientific classification
Kingdom: Animalia
Phylum: Mollusca (?)
Stem-group: Cephalopoda (?)
Family: †Nectocarididae
Genus: †Petalilium
Species: † P. latus
Binomial name
Petalilium latus
Luo & Hu 1999[1]
Synonyms

Petalilium (sometimes misspelled Petalium)[3] is an enigmatic genus of Cambrian organism of probable cephalopod affinity known from the Haikou area,[4] from the Maoshoiatan mudstone member of the Chengjiang biota.[5] The taxon is a junior synonym of Nectocaris pteryx.[6]

Morphology

Fossils of Petalilium[note 1] show a dorsoventrally flattened body, usually 5 to 6 centimetres, but ranging from 1.5 to 10 cm. It has an ovate trunk region and a large muscular foot, and a head with stalked eyes and a pair of long tentacles. The trunk region possesses about 50 soft, flexible, transverse bars, lateral serialised structures of unknown function. The upper part of the body, interpreted as a mantle, is covered with a random array of spines on the back, while gills project underneath. A complete, tubular gut runs the length of the body.

Classification

Whilst it was originally described as a phyllocarid,[1] and a ctenophore affinity has been suggested,[7] neither interpretation is supported by any compelling evidence.[8]

Some of the characters observed in Chen et al.'s 2005 study suggested that Petalilium may be related to mollusks, a view supported by its similarity to the putative early cephalopod Nectocaris.[2]

See also

Notes

  1. ↑ (originally described as Vetustovermis by Chen et al. 2005, but recognised as Petalilium by Smith & Caron 2010)

References

  1. ↑ 1.0 1.1 H. Luo, S. Hu, L. Chen, S. Zhang and Y. Tao, (1999). Early Cambrian Chengjiang fauna from Kunming region, China, Yunnan Science and Technology Press, Kunming, China (in Chinese with an English abstract)). p. 129.
  2. ↑ 2.0 2.1 Smith, M. R.; Caron, J. B. (2010). "Primitive soft-bodied cephalopods from the Cambrian". Nature 465 (7297): 469–472. Bibcode:2010Natur.465..469S. doi:10.1038/nature09068. PMID 20505727.
  3. ↑ Chen, J. Y.; Huang, D. Y.; Bottjer, D. J. (2005). "An Early Cambrian problematic fossil: Vetustovermis and its possible affinities.". Proceedings of the Royal Society, Part B 272 (1576): 2003–2007. doi:10.1098/rspb.2005.3159. PMC 1559895. PMID 16191609.
  4. ↑ Steiner, M.; Zhu, M.; Zhao, Y.; Erdtmann, B. (2005). "Lower Cambrian Burgess Shale-type fossil associations of South China". Palaeogeography, Palaeoclimatology, Palaeoecology 220: 129. doi:10.1016/j.palaeo.2003.06.001.
  5. ↑ Han, J.; Shu, D.; Zhang, Z.; Liu, J.; Zhang, X.; Yao, Y. (2006). "Preliminary notes on soft-bodied fossil concentrations from the Early Cambrian Chengjiang deposits". Chinese Science Bulletin 51 (20): 2482. doi:10.1007/s11434-005-2151-0.
  6. ↑ Smith, M. R. (2013). "Nectocaridid ecology, diversity and affinity: early origin of a cephalopod-like body plan". Paleobiology 39 (2): 291–321. doi:10.1666/12029.
  7. ↑ L.Z. Chen, H.L. Luo, S.X. Hu, J.Y. Yin, Z.W. Jiang, Z.L. Wu, F. Li and A.L. Chen (2002). Early Cambrian Chengjiang Fauna in Eastern Yunnan, China, Yunnan Science and Technology Press, Kunming (in Chinese and with English abstract)). p. 199.
  8. ↑ Hu, S.; Steiner, M.; Zhu, M.; Erdtmann, B. D.; Luo, H.; Chen, L.; Weber, B. (2007). "Diverse pelagic predators from the Chengjiang Lagerstätte and the establishment of modern-style pelagic ecosystems in the early Cambrian". Palaeogeography, Palaeoclimatology, Palaeoecology 254: 307. doi:10.1016/j.palaeo.2007.03.044.