Trachyplax arctica, a new multiplated probelematic fossil from the lower Cambrian of North Greenland
2009 (English)In: Acta Palaeontologica Polonica, ISSN 0567-7920, Vol. 54, no 3, 513-523 p.Article in journal (Refereed) Published
A new scleritome-bearing organism with eight sclerite types, Trachyplax arctica gen. et sp. nov., is described from the lower Cambrian Paralledal Formation of North Greenland. The originally calcareous sclerites are now silicified; no microstructures are preserved. The dominant sclerite type (A; maximum dimension 19.3 mm) is bilaterally symmetrical, strongly arched, with an oval shield showing co-marginal growth lines and a projecting rostrum with prominent radial ornamentation. A similar sclerite morphology can be identified in Silurian-Carboniferous multiplacophoran molluscs but the remaining sclerite types, which also display a combination of concentric and radial ornamentation, find no clear equivalents. Two models for scleritome reconstruction are presented, based on the relative abundance of the sclerites, but neither promotes a satisfactory assignment to a higher taxon. Despite the morphological dissimilarities, possibly reflecting the age discrepancy, reference to the Multiplacophora is most attractive and entails a substantial extension of the known geological range of that group.
Place, publisher, year, edition, pages
2009. Vol. 54, no 3, 513-523 p.
Trachyplax, Problematica, sclerites, scleritome, Multiplacophora, Cambrian, Greenland
Earth and Related Environmental Sciences
Research subject Historical Geology and Paleontology
IdentifiersURN: urn:nbn:se:uu:diva-108294DOI: 10.4202/app2009.0026ISI: 000270574400014OAI: oai:DiVA.org:uu-108294DiVA: diva2:235161