Английская Википедия:Ancyloceras
Шаблон:Short description Шаблон:Automatic taxobox
Ancyloceras is an extinct genus of heteromorph ammonites found throughout the world during the Lower Cretaceous, from the Lower Barremian epoch until the genus extinction during the Lower Aptian.[1][2][3]
Selected species
- Ancyloceras audouli Astier, 1851
- Ancyloceras fallauxi Uhlig, 1883
- Ancyloceras mantelli Casey, 1960
- Ancyloceras matheronianum d'Orbigny, 1842
- Ancyloceras vandenheckii Astier, 1851[1]
Description
Ancyloceras ammonites have a shell reaching a length of about Шаблон:Convert and a width of about Шаблон:Convert. They are known as heteromorph shaped, with a partly uncoiled shell and the aperture directed toward the coiled part.
Most ammonites are homomorph, as they maintain the same shape throughout the growth, while the ammonites in this genus have uncoiled shells (heteromorph or different-shaped ammonites), that would have precluded fast swimming.[1]
Distribution
Fossils of Ancyloceras species are found in the Cretaceous Barremian Stage (117-113 million year old) marine strata of Europe, Colombia and Morocco.
References
External links
- ↑ 1,0 1,1 1,2 Шаблон:Cite web
- ↑ Sepkoski, Jack Sepkoski's Online Genus Database – Cephalopoda
- ↑ Fossil Museum
