Landeroceras
| Landeroceras Temporal range: M -?U Ordovician | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | Discosorida |
| Family: | Cyrtogomphoceratidae |
| Genus: | Landeroceras Foerste 1935 |
Landeroceras is a genus of straight shelled cyrtogomphoceratid from the Middle Ordovician Big Horn dolomite of Wyoming.
The shell of Landeroceras is a subcylindrical brevicone with the siphuncle on one side, determined as ventral. Siphuncle segments are short and well expanded into the chambers. Connecting rings are thick, septal necks cyrochoanitic to recumbent, bullettes markedly swollen.
Landeroceras is at the end of a small offshoot within the discosorid family Cyrtogomphoceratidae that also includes Cyrtogomphoceras, and not in the line which gave rise to the Phragmoceratidae.
References
- Flower, R H and Teichert, C., 1957. The Cephalopod Order Discosorida. University of Kansas Paleontological Contributions. Mollusca, Article 6, pp 1-144.
- Teichert C. 1964. Nautiloidea -Discosorida, Treatise on Invertebrate Paleontology, Part K. Teichert and Moore eds.
This article is issued from Wikipedia - version of the 10/8/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.