Perspicaris (from the Latin perspicax, meaning “sharp-sighted,” and caris, “crab/shrimp”) an extinct genus of bivalved arthropod from the Cambrian period. Fossils have been found in North America, primarily the Burgess Shale of British Columbia, Canada but also possibly the Wheeler Shale, Marjum Formation, Pioche Shale and Bloomington Formation. Two named species are known from the Burgess Shale Perspicaris dictynna and Perspicaris recondita, which differ in maximum size (66 millimetres (2.6 in) in P. recondita vs 29 millimetres (1.1 in) in P. dictynna), as well as proportions of the tail. Both species have a pair of stalked eyes, as well as a pair of large segmented antennae. The tail is forked and spiny. They are thought to have been active swimmers (nektonic).[2]

Perspicaris
Temporal range: Miaolingian
Perspicaris dictynna (top) and Perspicaris. recondita (bottom) to scale. Scale bar = 5mm
Scientific classification
Kingdom:
Phylum:
Genus:
Perspicaris

Briggs 1977
Species
  • P. recondita Briggs 1977
  • P. dictynna (type species, =Canadaspis dictynna Simonetta & Delle Cave 1975)[1]

Perspicaris has been identified as a member of a clade Hymenocarina close to the crown-group of Euarthropoda, which includes myriapods, chelicerates, insects and crustaceans.[3][4]

References

edit
  1. ^ Briggs, D.E.G. (1977). "Archived copy" (PDF). Palaeontology. Archived from the original (PDF) on 24 August 2011. Retrieved 11 May 2010.{{cite journal}}: CS1 maint: archived copy as title (link)
  2. ^ "Perspicaris dictynna". The Burgess Shale. Royal Ontario Museum. Retrieved 27 October 2022.
  3. ^ Budd, G. (2002). "A palaeontological solution to the arthropod head problem". Nature. 417 (6886): 271–275. Bibcode:2002Natur.417..271B. doi:10.1038/417271a. PMID 12015599. S2CID 4310080.
  4. ^ Izquierdo‐López, Alejandro; Caron, Jean‐Bernard (November 2021). Zhang, Xi‐Guang (ed.). "A Burgess Shale mandibulate arthropod with a pygidium: a case of convergent evolution". Papers in Palaeontology. 7 (4): 1877–1894. doi:10.1002/spp2.1366. ISSN 2056-2799. S2CID 236284813.