Astreptoceras
| Astreptoceras Temporal range: | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | †Ammonoidea |
| Order: | †Ammonitida |
| Suborder: | †Ancyloceratina |
| Family: | †Diplomoceratidae |
| Genus: | † Henderson, 1970 |
| Species: | †A. zelandicum |
| Binomial name | |
| †Astreptoceras zelandicum (Marshall, 1926)[2] | |
| Synonyms | |
| |
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
- ^ Sepkoski, Jack (2002). "Sepkoski's Online Genus Database". Retrieved 2014-05-28.
- ^ a b c d "Astreptoceras zelandicum (Marshall, 1926)". Global Biodiversity Information Facility. Retrieved 24 October 2024.
- ^ Henderson, R.A. 1970 Ammonoidea from the Mata Series (Santonian-Maastrichtian) of New Zealand. Special papers in palaeontology, 6: 81 p.