Quasillites

Quasillites
Temporal range: Middle Devonian to Lower Carboniferous 388.1–342.8 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Ostracoda
Order: Platycopida
Family: †Quasillitidae
Genus: †Quasillites
Coryell & Malkin, 1936
Species
  • Quasillites angulatus
  • Quasillites fromelennensis
  • Quasillites lobatus (Schwartz & Oriel)
  • Quasillites obliquus (Coryell & Malkin, 1936)
  • Quasillites subobliquus

Quasillites is a fossil genus of ostracod from the Devonian and Carboniferous Periods.[1][2]

Description

Quasillites is distinguished from other ostracodes by the presence of a "medial spot" on each valve.[2] The surface of each valve is covered in longitudinal, bifurcating ridges, which curve and resemble a finger print.[2][3] The ribs and spines on the carapace are in front of the posterior margin, and are similar to those of other ostracods such as Bufina, Parabufina, and Healdia.[4] In fact, this comparison can also be drawn for all Quasillitids to other Healdiids.[4] The muscle scars on each valve is circular in shape, and some specimens have smaller secondary scars.[4]

Distribution

Devonian examples of Quasillites, such as Q. lobatus, Q. obliquus, Q. subobliquus, and Q. angulatus, are known from shales and claystones in northern New York, Eastern Ohio, central Pennsylvania.[2][3][5][6] Other species such as Q. fromelennensis and a second informal species can also be found in Limestones of northern France, near the city of Calais.[7] This genus has also been found in the Lower Carboniferous edge of the Illinois Basin; in central Indiana.[1]

References

  1. ^ a b J. J. Sepkoski Jr. 1998. Rates of speciation in the fossil record. Philosophical Transactions of the Royal Society Biological Sciences 353(1366):315-326
  2. ^ a b c d Moore, R., Lalicker, C., Fischer, A. 1952. Invertebrate Fossils.
  3. ^ a b Feldman, R. (ed.) 1996. Fossils of Ohio. Ohio Department of Natural Resources, Division of Geological Survey, Bulletin 70. pg. 115–121
  4. ^ a b c Moore, R. ed. Treatise on Invertebrate Paleontology. Volume Q. pp.88-94
  5. ^ L. E. Stover. 1956. Ostracoda from the Windom Shale (Hamilton) of Western New York. Journal of Paleontology. 30(5):1092-1142
  6. ^ R. L. Ellison. 1965. Stratigraphy and Paleontology of the Mahantango Formation in south-central Pennsylvania. Pennsylvania Geological Survey Bulletin.
  7. ^ P. Morzadec and D. Brice. 2000. The Devonian of France: a tentative tie with the GSSP of the Devonian stages. 225:115-129