Michelinoceras

Michelinoceras
Michelinoceras
Temporal range: Early Ordovician - Devonian, possibly to Late Triassic
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: Orthocerida
Family: Michelinoceratidae
Genus: Michelinoceras
Foeste, 1932

Michelinoceras is the oldest known genus of the Michelinocerida, more commonly known as the Orthocerida, characterized by long, slender, nearly cylindrical orthocones with a circular cross section, long camerae, very long body chambers, and a central or near central tubular siphuncle free of organic deposits. Septal necks are straight; connecting rings cylindrical and thin. Cameral deposits are well developed. A radula has been found in one species,[1] with seven teeth per row.[2] It had ten arms, two of which formed longer tentacles.[2]

Contents

Range

Michelinoceras ranges from late in the Early Ordovician to the Devonian with more poorly known species from the Carboniferous to the Late Triassic included in the genus. The earliest known for sure is Michelinoceras primum found in Cassinian age strata near the top of the El Paso Group in southern New Mexico and west Texas. A less well known species of Michelinoceras, M. primum?, comes from further down in the same formation, near the beginning of the Cassinian.

Taxonomy and derivation

Michelinoceras named by Foeste in 1932 is the ancestral and characteristic genus of the Michelinoceratidae, established and described by Flower in 1946; derived from empty siphuncle Baltoceratidae.

See also

List of nautiloids

References

  1. ^ Gabbott, Sarah E. (1999). "Orthoconic cephalopods and associated fauna from the late Ordovician Soom Shale Lagerstatte, South Africa". Palaeontology 42: 123. doi:10.1111/1475-4983.00065.  edit
  2. ^ a b Mehl, J. (1984). "Radula und Fangarme bei Michelinoceras sp. aus dem Silur von Bolivien [Radula and arms of Michelinoceras sp. from the Silurian of Bolivia]" (in German). Paläontologische Zeitschrift 58 (3 / 4): 211–229. doi:10.1007/BF02986061. http://www.springerlink.com/content/006556ml2167235n/.  edit
  • Flower, R.H. 1976; Ordovician Cephalopod Faunas and Their Role in Correlation, pp 538-541; proceedings pub. Paleontological Association, Gr Br.
  • Hook, J.C. and Flower , R.H. 1976; Tajaroceras and the Origin fo the Troedsonnellidae. Jour Paleontology v 50, no 2, pp 293-300, March 1976
  • Sweet, W.C, 1964; Michelinoceras, pp 225-226 in Orthoceratidae, pp 224-231 in the Treatise on Invertebrate Paleontology Vol K. GSA and Univ Kansas Press.

Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Dinosaur Train — Title screen logo Also known as Jim Henson s Dinosaur Train Genre Children s CGI animated cartoon Created by Craig …   Wikipedia

  • Orthoceras — For the orchid genus, see Taxonomy of the orchid family. Orthoceras Temporal range: 488–199.6 Ma …   Wikipedia

  • Orthoceratidae — Temporal range: Ordovician Permian (possibly Triassic) Orthoceras Scientific classification Kingdom …   Wikipedia

  • Bactritida — Taxobox name = Bactritida regnum = Animalia phylum = Mollusca classis = Cephalopoda subclassis = Bactritoidea ordo = Bactritida ordo authority = Shimanskiy 1951 The Bactritida form a small order of more or less straight shelled (orthoconic)… …   Wikipedia

  • Ordovizium — Or|do|vi|zi|um 〈[ vi: ] n.; s; unz.; Geol.〉 Formation des Paläozoikums (zw. Kambrium u. Silur) vor 460 410 Mio. Jahren mit beginnender kaledonischer Gebirgsbildung u. erstem Auftreten von Kephalopoden [nach dem kelt. Volksstamm der Ordovizier… …   Universal-Lexikon

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”