Monophyllites

Monophyllites
Temporal range: Anisian–Ladinian[1]
Fossil of M. sphaerophyllus fossil from Bosnia
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Suborder: Phylloceratina
Family: Ussuritidae
Genus: Monophyllites
Mojsisovics 1879
Species

See text.

Monophyllites is an extinct cephalopod genus belonging to the family Ussuritidae that lived during the Triassic period, from Anisian to Ladinian age.[1]

Description

"Form evolute laterally compressed. Whorl low and increasing slowly in height, little embracing and not deeply indented by the inner volution. Sides somewhat flattened, venter rounded with indistinct abdominal shoulders. Umbilicus wide and shallow exposing the greater part of the inner volutions. Umbilical shoulders abruptly rounded. The height of the whorl is more than one third of the total diameter of the shell and the breadth is about three fourths of the height of the whorl The width of the umbilicus is about one third of the total diameter of the shell. The surface is nearly smooth being ornamented only with the fiexuous striae of growth. The septa are monophyllic, the saddles rounded entire, contracted at the base and the lobes are digitate. The external lobe is divided by a narrow siphonal saddle into two bifid divisions the first lateral is distinctly and symmetrically trifid the second lateral unsymmetrically trifid. The auxiliary consists of three small secondary divisions of the umbilical lobe. Internal septa unknown"

(Original description by Hyatt and Smith, 1905).[2]

Species

The following species are recognized in the genus Monophylites[3]

Distribution

Fossils of species within this genus have been found in the Triassic of Afghanistan, Albania, Canada, Hungary, Italy, Japan, New Zealand, Oman, Pakistan, Russia, Switzerland, Turkey, United States.[3]

References

  1. 1 2 Sepkoski, Jack (2002). "Sepkoski's Online Genus Database". Retrieved 2014-05-28.
  2. J- Perrin Smith. THE MIDDLE TRIASSIC MARINE INVERTEBRATE FAUNAS OF NORTH AMERICA, pg. 48
  3. 1 2 Paleobiology Database - Monophyllites 28 May 2014
  4. Discover Yale Digital content
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