Tamisiocaris
| Tamisiocaris | ||||||||||
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| Temporal occurrence | ||||||||||
| Lower Cambrian | ||||||||||
| 521 to 514 million years | ||||||||||
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Tamisiocaris | ||||||||||
| Daley & Peel , 2010 | ||||||||||
Tamisiocaris is an extinct arthropod that lived in the seas of the Lower Cambrian (2nd series, 3rd stage). Its fossil remains belong to the Sirius Passet fauna community in the far north of Greenland . To date,only one species of the genus is known, Tamisiocaris borealis .
features
From tamisiocaris only five isolated head appendages and two head appendages with head shield are known. The head extensions are about 12 cm long and thus about as long as those of Anomalocaris . The total length of Tamisiocaris is unknown. The head extensions are divided into 18 segments and slightly curved downwards. Each segment has a pair of V-shaped spaced apart, long and narrow spines on its underside, which are 26 to 27.5 mm long and 6 to 7 mm apart. The spines have a further 4.2 to 5 mm long, extremely thin spines on their front and rear edges, which are 0.3 to 0.85 mm apart, so that overall a comb-like structure results. Tamisiocaris was probably a nektonic filter feeders that extends from zooplankton medium size (mesozooplankton), comparable to most recent copepods , malnourished, which he filtered using his head appendages from the water.
etymology
The generic name is made up of the Latin word tamisium for sieve, based on the likely sieving function of the ventral spines, and the Greek word caris for shrimp. The Latin epithet borealis means coming from the north.
Location
So far, only incomplete specimens of this species have been found in the Lower Cambrian fossil deposit Sirius-Passet on the Pearyland peninsula in Greenland . The holotype (MGUH 29,154) is now in the Geological Museum in Copenhagen , part of the National Museum of Denmark .
Systematics
Tamisiocaris was placed together with Anomalocaris briggsi , the species also has delicate spines on its head extensions, in the family of the Cetiocaridae from the parent group of the Anomalocaridida (order Radiodonta ).
literature
- Allison C. Daley, John S. Peel: A possible anomalocaridid from the Cambrian Sirius Passet deposit, North Greenland . Journal of Paleontology 84, 2010: 352-355. HTML
- Allison C. Daley: The morphology and evolutionary significance of the anomalocaridids . Acta Universitatis Upsaliensis. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 714. 2010, 40 pp. PDF
- Jakob Vinther, Martin Stein, Nicholas R. Longrich & David AT Harper: A suspension-feeding anomalocarid from the Early Cambrian. Nature 501: 496-499. doi: 10.1038 / nature13010