Ancyloceras

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]

Ancyloceras
Temporal range: Lower Barremian to Lower Aptian
Ancyloceras
Scientific classification
Kingdom:
Animalia
Phylum:
Mollusca
Class:
Cephalopoda
Subclass:
Ammonoidea
Order:
Ammonitida
Family:
Ancyloceratidae
Genus:
Ancyloceras

d'Orbigny, 1842
  • See text

Selected species
  • A. audouli Astier, 1851
  • A. fallauxi Uhlig, 1883
  • A. mantelli Casey, 1960
  • A. matheronianum d'Orbigny, 1842
  • A. vandenheckii Astier, 1851[1]

Description

Ancyloceras ammonites have a shell reaching a length of about 10 centimetres (3.9 in) and a width of about 7 centimetres (2.8 in). 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 and Morocco.

gollark: Technically I could make potatOS preempt the thing force-rebooting it so that the user takes their fingers off the keys, but it doesn't do that.
gollark: However, the actual `reboot` command in the sandbox does *not* reboot it fully.
gollark: I can't get around that.
gollark: No, it does.
gollark: - PotatOS uses a single global process manager instance for nested potatOS instances. The ID is incremented by 1 each time a new process starts.- But each nested instance runs its own set of processes, because I never made them not do that and because without *some* of them things would break.- PotatOS has a "fast reboot" feature where, if you reboot in the sandbox, instead of *actually* rebooting the computer it just reinitializes the sandbox a bit.- For various reasons (resource exhaustion I think, mostly), if you nest it, stuff crashes a lot. This might end up causing some of the nested instances to reboot.- When they reboot, some of their processes many stay online because I never added sufficient protections against that because it never really came up.- The slowness is because each event goes to about 200 processes which then maybe do things.

References
  1. Paleobiology Database
  2. Sepkoski, Jack Sepkoski's Online Genus Database – Cephalopoda
  3. Fossil Museum


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