Liwia

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Liwia
Temporal range: Early Cambrian 520–516  Ma
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Liwia reconstruction.png
Reconstruction
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Order: Nektaspida
Family: Liwiidae
Genus: Liwia
Dzik and Lendzion, 1988
Species
  • Liwia plana Lendzion, 1975
  • Liwia convexa Lendzion 1975

Liwia is a genus of liwiid nektaspid. [1] It includes the species Liwia plana and Liwia convexa, both known from borehole samples several kilometers in depth from the Zawiszyn Formation in Poland, which has also yielded Peytoia infercambriensis.

Contents

Discovery and naming

The holotype of fossil of Liwia was found from the Zawiszyn Formation of Poland, and described in 1975. [2]

The original generic name Livia is derived from the name of the Liwiec River, near to where the fossils were found, [2] although as this generic name was already preoccupied, it was changed in 1988 to Liwia. [3]

The specific name for L. convexa derives directly from the Latin word convexa, to mean "rounded", relating to the curved appearance of the pygidium; whilst the specific name for L. plana derives directly from the Latin word plana, to mean "flat", relating the overall flatness of this species. [2]

Description

Liwia is a genus of nektaspida, and the namesake of the Liwiidae family, growing to around 20–30 mm (0.8–1.2 in) in length, with the longer, incomplete species being L. convexa; and the shorter, more complete species being L. plana. [2]

They have a oval shaped cephalon, with four thoracic segments, and a distinctive spiked pygidium, of which there are six pairs of rear-facing spines, with the three anterior spines being shorter, whilst the three posterior spines are longer. [2]

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References

  1. Budd, G. E. (1999). "A nektaspid arthropod from the Early Cambrian Sirius Passet fauna, with a description of retrodeformation based on functional morphology". Palaeontology. 42: 99–122. Bibcode:1999Palgy..42...99B. doi: 10.1111/1475-4983.00064 . S2CID   128566745.
  2. 1 2 3 4 5 Lendzion, Kazimiera (1975). "Fauna of the Mobergella zone in the Polish Lower Cambrian". Geological Quarterly. 19 (2): 237–242. ISSN   1641-7291.
  3. Dzik, Jerzy; Lendzion, Kazimiera (January 1988). "The oldest arthropods of the East European Platform". Lethaia. 21 (1): 29–38. doi:10.1111/j.1502-3931.1988.tb01749.x.