Izumonauta

Taxobox
name = "Izumonauta"
status = fossil
fossil_range = Miocene


image_caption =
regnum = Animalia
phylum = Mollusca
classis = Cephalopoda
ordo = Octopoda
superfamilia = Argonautoida
familia = Argonautidae
genus = "Izumonauta"
genus_authority = Kobayashi, 1954
subdivision_ranks = Species
subdivision =
*"Izumonauta lata"
Kobayashi, 1954
*"Izumonauta kagana"
Kaseno, 1955
*"Izumonauta kasataniensis"
Kaseno, 1955

"Izumonauta" is an extinct genus of shelled octopods from the Mid to Late Miocene of Japan and New Zealand. [Kobayashi, T. (1954). "Izumonauta", a new genus of the Argonautinae, with a note on their rare but gregarious fossil occurrence. "Japanese Journal of Geology and Geography" 25: 21-34.]

The keels of "Izumonauta" eggcases lack tubercules and are intermediate in morphology between those of the earlier "Obinautilus" and later "Argonauta". [cite journal | author = Saul, L. & C. Stadum | year = 2005 | title = Fossil Argonauts (Mollusca: Cephalopoda: Octopodida) From Late Miocene Siltstones Of The Los Angeles Basin, California | journal = Journal of Paleontology | volume = 79 | issue = 3 | pages = 520–531 | url = http://apt.allenpress.com/aptonline/?request=get-abstract&issn=0022-3360&volume=079&issue=03&page=0520 | doi = 10.1666/0022-3360(2005)079<0520:FAMCOF>2.0.CO;2 | doilabel = 10.1666/0022-3360(2005)0790520:FAMCOF2.0.CO;2]

The New Zealand fossil material was described from the Kapitean Stage (uppermost Miocene). [Marshall, B.A. (1971). "Izumonauta" (Argonautidae, Cephalopoda, Coleoida) from the Kapitean Stage (Uppermost Miocene) of New Zealand. "New Zealand Journal of Geology and Geophysics" 14: 288-292.]

References

Further reading

*Yanagisawa, Y. 1990. PDFlink| [http://www.gsj.jp/Pub/Bull/vol_41/41-03_02.pdf Age of fossil Argonautidae (Cephalopoda) from Hokuriku Province (central Honshu, Japan) based on diatom biostratigraphy.] |1.90 MiB "Bull. Geol. Surv. Japan" 41 (3): 115-127.