Biology:Annuloceras

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Short description: Genus of molluscs (fossil)


Annuloceras
Temporal range: Barremian[1]
Annuloceras summersi.JPG
Annuloceras summersi
Scientific classification
Kingdom:
Phylum:
Class:
Order:
Suborder:
Superfamily:
Protancyloceratoidea
Family:
Aegocrioceratidae
Genus:
Annuloceras

Murphy et al, 1995
Species
  • A. summersi

Annuloceras ("Ringed Horns") is an extinct genus of ammonite cephalopod. Its fossils are found in Lower Barremian sediments from California . The genus is currently placed in the family Aegocrioceratidae.[2]

Annuloceras is a heteromorph ammonite similar in form to other heteroceratids except that the early helix is more loosely wound. Macroscaphites differs in that the early portion is planispiral and tightly wound. Contemporary Shastoceras, found the same strata in California, differs in lacking a coiled juvenile section.

References

  1. Sepkoski, Jack (2002). "Sepkoski's Online Genus Database". http://strata.geology.wisc.edu/jack/showgenera.php?taxon=231&rank=class. 
  2. Klein, J. (2007). "Lower Cretaceous Ammonites III Bochianitoidea, Protancyloceratoidea, Ancyloceratoidea, Ptychoceratoidea.". Fossilium Catalogus I: Animalia 144: 1–381. 
  • A New Heteromorph Ammonite from the Barremian (Cretaceous) of California Michael A. Murphy, Peter U. Rodda, Patrick Embree Journal of Paleontology, Vol. 69, No. 6 (Nov., 1995), pp. 1179–1182 abstract

Wikidata ☰ Q3726678 entry