Obinautilus

Obinautilus
Temporal range: Oligocene – Pliocene
Obinautilus awaensis
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Superfamily: Argonautoida
Family: Argonautidae
Genus: Obinautilus
Kobayashi, 1954
Species

Obinautilus is an extinct genus of shelled octopods from the Late Oligocene to Late Miocene of Japan.[1] The shell is discoidal and very involute, with rapidly expanding and compressed whorls, fine radial ribs, a rounded venter with a shallow furrow, and almost closed umbilicus.

Based on the examination of O. pulcher fossils from the Oligocene, the Tremoctopus-Argonauta divergence has been calculated to have occurred at least 29 million years ago.[2]

References

  1. ^ Saul, L. & C. Stadum (2005). "Fossil Argonauts (Mollusca: Cephalopoda: Octopodida) From Late Miocene Siltstones Of The Los Angeles Basin, California". Journal of Paleontology 79 (3): 520–531. doi:10.1666/0022-3360(2005)079<0520:FAMCOF>2.0.CO;2. http://apt.allenpress.com/aptonline/?request=get-abstract&issn=0022-3360&volume=079&issue=03&page=0520. 
  2. ^ Strugnell, J., J. Jackson, A.J. Drummond & A. Cooper (2006). Divergence time estimates for major cephalopod groups: evidence from multiple genes. Cladistics 22 (1): 89-96.

Further reading