Parvancorina
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Parvancorina is a shield shaped Ediacaran fossil. It has a raised ridge down the central axis of symmetry. This ridge can be high in unflattened fossils. At the 'head' end of the ridge there are two quarter circle shaped raised arcs attached. In front of this are two nested semicircular lines. Teeth seem to come from the raised parts pointing into the centre spaces. These may show as raised lines. The fossils are normally about 1 cm in each of width, length and height, but can be up to 2 cm.
Parvancorina is compared with the Burgess Shale organism Burgessia, and also to Skania fragilis, and is similar in shape to a trilobite. Similar fossils are found in the middle Cambrian beds in the middle Kaili Formation near Balang, Guizhou, China. Parvancorina also resembles the meraspid larval form of trilobites.[1]
Parvancorina was originally described by Martin Glaessner in 1958. One species is P. minchami. It is found in Ediacara Hills in South Australia. These are dated around 555 mya.
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[edit] References
- ^ Trilobite ancestry - URL retrieved 9 February 2007
- Glaessner, M.F. 1958: New Fossils from the Base of the Cambrian in South Australia. Transactions Royal Society of South Australia 81: 185-188.
- Lin Jih-Pai, Gon, S. M., III, Gehling, J. G., Babcock, L. E., Zhao Yuan-Long, Zhang Xing-Liang, Hu Shi-Xue, Yuan Jin-Liang, Yu Mei-Yi & Peng Jin. 2006. A Parvancorina-like arthropod from the Cambrian of South China. Historical Biology 18: 33-45. Abstract - URL retrieved November 30 2006
- Glaessner, M.F. 1980: Parvancorina - an arthropod from the Late Precambrian fauna of the Ediacara Fossil Reserve. Records of the South Australia Museum 13:83-90
