Asthenoceras

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Asthenoceras
Temporal range: Bajocian [1]
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Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Family: Sonniniidae
Subfamily: Witchelliinae
Genus: Asthenoceras
Buckman, 1899
Species [2]

See text

Asthenoceras is a genus of ammonoid from the Middle Jurassic (Lower Bajocian) with dwarfish, evolute, smooth, compressed, discoidal, strongly keeled shell. Asthenoceras belongs to the Sonniniidae and may be a subgenus of the Lower Jurassic (Upper Toarcian) Grammoceras .

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<i>Berriasella</i>

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Hildoceras is a genus of ammonite from the Jurassic period in the family Hildoceratidae. The shells are characterized by a narrow discoidal evolute shape, keeled venter, concave ribs along the outer flanks, and a shallow spiral groove running along smooth inner flanks. Whorls slightly overlap, cross sections are compressed. The ventral keel is bordered on either side by a shallow groove. The genus was named by Alpheus Hyatt after Saint Hilda in 1876.

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<i>Euaspidoceras</i>

Euaspidoceras is an extinct ammonoid cephalopod genus that lived during the Middle Jurassic.

Ochetoceras is a genus of ammonites, belonging to the Oppeliidae, that lived during the Late Jurassic from the early Oxfordian to the early Tithonian, and type for the subfamily Ochetoceratinae.

References

  1. Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Cephalopoda entry)". Bulletins of American Paleontology. 363: 1–560. Archived from the original on 2016-02-25. Retrieved 2017-10-18.CS1 maint: discouraged parameter (link)
  2. "Paleobiology Database - Asthenoceras" . Retrieved 2017-10-19.CS1 maint: discouraged parameter (link)