Biology:Grammoceras
From HandWiki
Short description: Genus of ammonite
| Grammoceras | |
|---|---|
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | †Ammonoidea |
| Order: | †Ammonitida |
| Family: | †Hildoceratidae |
| Subfamily: | †Grammoceratinae |
| Genus: | †Grammoceras Hyatt, 1867 |
| Species | |
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Grammoceras is an extinct genus of ammonite found in Yorks Ravenscar, England, from Jurassic period sediments. Its overall distribution is fairly worldwide.
Grammoceras has a thin, discoidally evolute shell with simple, gently sigmoid ribbing and a low ventral keel. Dumortiera and Catulloceras from the same age are similar except that Dumortiera has a more rounded venter and Catulloceras has a subquadrate whorl section. Asthenoceras from the slightly younger lower Bajocian may be a subgenus.
References
- ↑ Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Cephalopoda entry)". Bulletins of American Paleontology 363: 1–560. Archived from the original on 2008-05-07. https://web.archive.org/web/20080507014300/http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=231&rank=class. Retrieved 2017-10-18.
- Arkell, W.J.; Kummel, B.; Wright, C.W. (1957). Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Lawrence, Kansas: Geological Society of America and University of Kansas Press.
Wikidata ☰ Q5593715 entry
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