Allonautilus scrobiculatus

Allonautilus scrobiculatus
Allonautilus scrobiculatus shell with periostracum removed
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Nautilida
Family: Nautilidae
Genus: Allonautilus
Species: A. scrobiculatus
Binomial name
Allonautilus scrobiculatus
(Lightfoot, 1786)
Synonyms
  • Nautilus scrobiculatus
    Lightfoot, 1786
  • ?Nautilus umbilicatus
    Linne, 1758

Allonautilus scrobiculatus, also known as the Crusty Nautilus, is a species of nautilus native to the waters around New Guinea, specifically New Britain and Milne Bay, and the Solomon Islands. A. scrobiculatus is instantly recognisable by the large open umbilicus, which is around 20% of the shell diameter at its widest point. This species, along with the closely related A. perforatus, were originally placed in the genus Nautilus, but have recently been given their own genus on account of significant morphological differences.[1] The most obvious are features of the shell, including crease and an encrusting layer (periostracum) that covers most of the shell. Gills and reproductive structures also differ significantly from members of the genus Nautilus. The shell is usually up to around 18 cm in diameter, although the largest specimen ever recorded measured 215 mm.[2]

References

  1. ^ Ward, P.D. & W.B. Saunders 1997. Allonautilus: a new genus of living nautiloid cephalopod and its bearing on phylogeny of the Nautilida. Journal of Paleontology 71(6): 1054–1064.
  2. ^ Pisor, D. L. (2005). Registry of World Record Size Shells (4th edition ed.). Snail's Pace Productions and ConchBooks. p. 93. 

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