Parvancorina minchami Glaessner, 1958
incertae sedis
Ediacaran
Ediacara Mbr, Rawnley Quartzite Fm
South Australia
Length: 1 cm
Parvancorina ("small anchor") is a common enigmatic fossil from the Ediacaran fauna. It was once thought to be a fixed animal attached to the seafloor but both a statistic study of fossil orientations with respect to current flow and fluid dynamic simulations indicate that it was most likely mobile. It was thought to be an ancestral form of the trilobites because of some similitude in morphology with primitive Cambrian forms such as Skania and Primicaris, but a trilobite affinity is now considered doubtful. Two species have been described, P. minchami from both South Australia and Russia, and the smaller P. sagitta from Russia.
References:
Glaessner, M. F. (1979). Parvancorina—an arthropod from the Late Precambrian (Ediacarian) of South Australia. Annalen des Naturhistorischen Museums in Wien, 83-90.
Paterson, J. R., Gehling, J. G., Droser, M. L., & Bicknell, R. D. (2017). Rheotaxis in the Ediacaran epibenthic organism Parvancorina from South Australia. Scientific Reports, 7, 45539.
Darroch, S. A., Rahman, I. A., Gibson, B., Racicot, R. A., & Laflamme, M. (2017). Inference of facultative mobility in the enigmatic Ediacaran organism Parvancorina. Biology Letters, 13(5), 20170033.
June 23, 2017
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