Aspidoceras
Aspidoceras Temporal range: Oxfordian–Berriasian[1] | |
---|---|
Aspidoceras species | |
Scientific classification | |
Phylum: | Mollusca |
Class: | Cephalopoda |
Subclass: | Ammonoidea |
Order: | Ammonitida |
Superfamily: | Perisphinctaceae |
Family: | Aspidoceratidae |
Genus: | Aspidoceras Zidttel, 1868 |
Aspidoceras is an extinct ammonoid cephalopod genus that lived during the Late Jurassic (Kimmeridgian) with a fairly broad distribution. Aspidoceras, named by Zittel, 1868, is the type genus for the persphictacian family Aspidoceratidae and subfamily Aspidoceratinae in which it is included.
Aspidoceras has an evolute shell with quadrate-rounded or depressed whorls that have two rows of tubercles, the outer near the middle of the whorl sides. The outer row soon fades in many species. Some species are also ribbed. The venter, or outer rim, is generally wide and broadly arched.
Aspidoceras is predated by Euaspidoceras, possibly its ancestor, and is considered related to genera like Orthaspidoceras, Simaspidoceras, and Intranodites.
References
- ↑ Sepkoski, Jack (2002). "Sepkoski's Online Genus Database". Retrieved 2014-05-28.
- Arkell, et al.,1957. Mesozoic Ammonoidea; Treatise on Invertebrate Paleontology, Part L (Ammonoidea). Geol Soc of America and Univ Kansas Press. p. L338-339.
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