Gymnites

This article is about a genus of cephalopods. For the form of antigorite, see Gymnite.

Gymnites
Temporal range: Triassic, 247.2–235.0 Ma [1]
Gymnites incultus from Bosnia, on display at Galerie de paléontologie et d'anatomie comparée in Paris
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: †Ammonoidea
Order: †Ceratitida
Family: †Gymnitidae
Genus: †Gymnites
Mojsisovics, 1882

Gymnites is a genus of ammonoid cephalopod from the Middle Triassic belonging to the ceratitid family Gymnitidae. These nektonic carnivores lived during the Triassic period, the Anisian age.[2]

Species

[1]

  • Gymnites aghdarbandensis Krystyn and Tatzreiter 1991
  • Gymnites asseretoi Tozer 1972
  • Gymnites billingsi Bucher 1989
  • Gymnites calli Smith 1914
  • Gymnites compressus Tozer 1994
  • Gymnites evolutus Shevyrev 1995
  • Gymnites humboldti Mojsisovics 1882
  • Gymnites incultus Beyrich 1867
  • Gymnites machangpingensis Zhao and Wang 1974
  • Gymnites perplanus Meek 1877
  • Gymnites petilus Wang and Chen 1979
  • Gymnites procerus Tozer 1994
  • Gymnites robinsoni Shevyrev 1995
  • Gymnites toulai Arthaber 1914
  • Gymnites tozeri Bucher 1992
  • Gymnites tregorum Silberling and Nichols 1982
  • Gymnites vastesellatus Welter 1915

Description

The shell of Gymnites is evolute, generally smooth, with a wide umbilicus. Whorls are moderately embracing, whorl section oval and somewhat compressed. The outer whorl may be costate have rows of nodes, or both. The suture is ammonitic with a wide bifurcated ventral lobe and two lateral lobes on either side.

Taxonomic relation

Hyatt and Smith (1905, p. 115)included Gymnites in the Gymnitidae along with Ophiceras, Flemingites, and Xenaspis, genera since assigned elsewhere, and included the Gymnitidae in the suborder Ceratitoidea (now the superfamily Ceratitaceae). Smith (1932, p. 30) shows Gymenites derived from Xenaspis and giving rise to the Pinacoceratidae.

The American Treatise (Part L, 1957) also includes Gymnites in the Gymnitidae, along with mainly descendant forms such as Buddhaites, Japonites, and variations on Gymnites itself, but instead included the Gymnitidae in the Pinacocerataceae which is consistent with Smith's derivation of the Pinacoceratidae from Gymnites.

Distribution

Fossils of species within this genus have been found in the Triassic of Afghanistan, Canada, China, Hungary, Iran, Russia, Switzerland, Turkey, United States.[1]

References

  1. ^ a b c The Paleobiology Database
  2. ^ Sepkoski, Jack Sepkoski's Online Genus Database – Cephalopoda
  • Alpheus Hyatt and James Perrin Smith, 1905. The Triassic Cephalopod General of America. United States Geological Survey Professional Paper no. 40.
  • James Perrin Smith, 1932. Lower Triassic Ammonoids of North America. U.S. Geological Survey PP 167.
  • Treatise on Invertebrate Paleontology, Part L, Ammonoidea. Geol Soc. of America and Univ. Kansas Press, 1957. p. L184.