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Astreptoceras

From Wikipedia, the free encyclopedia

Astreptoceras
Temporal range: Campanian[1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Suborder: Ancyloceratina
Family: Diplomoceratidae
Genus: Astreptoceras
Henderson, 1970
Species:
A. zelandicum
Binomial name
Astreptoceras zelandicum
(Marshall, 1926)[2]
Synonyms
  • Ptychoceras zelandicum (Marshall, 1926)[2]

Astreptoceras is an extinct upper Cretaceous ammonoid cephalopod named by Henderson in 1970.[2] Fossils belonging to this genera have been found in Antarctica and New Zealand.

The only described species is Astreptoceras zelandicum (Marshall, 1926).[2] It is a small heteromorph ammonite with almost circular cross-section of the shell. Shell has probably only one straight shaft that is initially without ribs and constrictions. At diameter of about 2 mm there appears first constrictions and at late growth stages, these can be preceded by a collar and shallow secondary constriction. Weak ribs occurs at late growth stages.[3]

References

[edit]
  1. ^ Sepkoski, Jack (2002). "Sepkoski's Online Genus Database". Retrieved 2014-05-28.
  2. ^ a b c d "Astreptoceras zelandicum (Marshall, 1926)". Global Biodiversity Information Facility. Retrieved 24 October 2024.
  3. ^ Henderson, R.A. 1970 Ammonoidea from the Mata Series (Santonian-Maastrichtian) of New Zealand. Special papers in palaeontology, 6: 81 p.
  • Nomenclator Zoologicus [1]
  • Sepkoski's list of cephalopod genera [2]