Skania

Skania is a Cambrian fossil arthropod. The type species, S. fragillis, is known from the Burgess Shale of British Columbia, Canada. A second possible species "S." sundbergi is known from the Kaili Formation of China,[1] but its placement within the genus has been questioned.[2]

For the Swedish province, see Scania.

Skania
Temporal range:
Illustration of Skania fragilis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: †Marrellomorpha
Order: †Acercostraca
Genus: †Skania
Walcott, 1931
Species
  • S. fragilis Walcott, 1931
  • S. sundbergi

Description

Specimens of S. fragillis range in length from 7.5 mm to 13.5 mm. The cordiform dorsal shield/carapace covers the entire body, with its midline having a raised keel. The shield curls around the front to form a doublure, with the posterior eddge of the doublure having a pair of lateral spines. A pair of spines is also present on the posterior of the dorsal shield. There are two sets of appendages, the first 5 pairs of appendages are elongate, somewhat curved and extend beyond the shield. In contrast, the trunk appendages are shorter and are less curved.[2]

Specimens of "S." sundbergi are on average 7.92 mm in length. The midline keel is more strongly pronounced in "S." sundbergi. The spines present in S. fragillis are either more weakly developed or absent.[1][2]

Taxonomy

While previously enigmatic, it is now thought to be a marrellomorph, with both species, regardless of generic placement, belonging to Acercostraca.[2] The resemblance with the Ediacaran organism Parvancorina, to which Skania had previously been suggested to be closely related as part of the proposed clade "Parvancorinomorpha",[1] is superficial and they are probably not related.[2]

References
  1. Lin, J. P.; Gon, S. M.; Gehling, J. G.; Babcock, L. E.; Zhao, Y. L.; Zhang, X. L.; Hu, S. X.; Yuan, J. L.; Yu, M. Y.; Peng, J. (2006). "A Parvancorina-like arthropod from the Cambrian of South China". Historical Biology. 18 (1): 33–45. doi:10.1080/08912960500508689.
  2. Legg, D.A. (2015-09-30). "The morphology and affinities of Skania fragilis (Arthropoda) from the middle Cambrian Burgess Shale". Bulletin of Geosciences: 509–518. doi:10.3140/bull.geosci.1532. ISSN 1802-8225.


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.