Barnesoceras

Barnesoceras is a genus of moderately large, Lower Ordovician ellesmoerceratids with a simple, but strongly cyctoconic shell that expands in the vertical dimension more rapidly than in the horizontal, resulting in its being laterally compressed. The aperture is simple, unconstricted, and straight sided from in front. Growth lines show a broad crest on either side that swings forward above the ventral hyponomic sinus. Septa are close spaced and have a shallow curvature. The body, or living, chamber takes up much of the shell. The siphuncle is ventral, close to the longitudinally concave side.

Barnesoceras
Temporal range: Early Ordovician
Scientific classification
Kingdom:
Phylum:
Class:
Subclass:
Superorder:
Order:
Family:
Genus:
Barnesoceras

Flower, 1964

All eight species named and described, including the type, Barnsoceras clavum Flower, 1964, were found in the Threadgill Limestone of the Lower Ordovician Tanyard Formation in Texas.

References

    • R.H. Flower, 1964. The Nautiloid Order Ellesmeroceratida (Cephalopoda). Memoir 12. New Mexico Bureau of Mines and Mineral Resources, Socorro NM.


    This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.