Calymene

Calymene
Temporal range: Tremadocian to Pragian488.300–409.100Ma
Calymene clavicula 32mm, Henryhouse Formation, Oklahoma, Cayugan
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Trilobita
Order: Phacopida
Family: Calymenidae
Genus: Calymene
Münster, 1840
Type species
Calymene blumenbachii
Brongniart in Desmarest, 1817 [1]

Calymene (meaning beautiful crescent as a reference to the glabella) is a genus of trilobites in the order Phacopida that are found throughout North America, North Africa, and Europe in primarily Silurian outcrops.[2] Calymene is closely related to Flexicalymene, and both genera are frequently found inrolled.[3] Calymene trilobites are small, typically 2cm in length. Their cephalon is the widest part of the animal, and the thorax is usually in 13 segments.[4]

Known species and locations

Reassigned species

Since the genus Calymene was established early on in paleontology, a number of species previously assigned to it have since been transferred to other genera:[7]

References

  1. 1.0 1.1 Derek J. Siveter (1985). "The type species of Calymene (Trilobita) from the Silurian of Dudley, England" (PDF). Palaeontology 28 (4): 783–792.
  2. "†Calymene Muenster 1840 (trilobite)". The Paleontology Database. Retrieved April 29, 2012.
  3. John P. Rafferty, ed. (2010). The Paleozoic Era: Diversification of Plant and Animal Life. Geologic History of Earth. Britannica Educational Publishing. ISBN 978-1-61530-196-6.
  4. Milson, C. and Rigby, S. (2004). Fossils at a Glance. Oxford: Blackwell Science Ltd.
  5. "Calymene celebra Raymond 1916 (trilobite)". Paleobiology Database. Retrieved 20 August 2011.
  6. Alex J. Chestnut. "Using morphometrics, phylogenetic systematics and parsimony analysis to gain insight into the evolutionary affinities of the Calymenidae Trilobita". OhioLINK ETD Center. Retrieved August 21, 2011.
  7. Moore, R.C. (1959). Arthropoda I - Arthropoda General Features, Proarthropoda, Euarthropoda General Features, Trilobitomorpha. Treatise on Invertebrate Paleontology. Part O. Boulder, Colorado/Lawrence, Kansas: Geological Society of America/University of Kansas Press. pp. 1–560. ISBN 0-8137-3015-5.
  8. Ramskjöld, L.; Werdelin, L. (1991). "The phylogeny and evolution of some phacopid trilobites". Cladistics 7: 29–74. doi:10.1111/j.1096-0031.1991.tb00021.x.

External links