Allonautilus: a new genus of living nautiloid cephalopod and its bearing on phylogeny of the Nautilida

  title={Allonautilus: a new genus of living nautiloid cephalopod and its bearing on phylogeny of the Nautilida},
  author={Peter D. Ward and W Bruce Saunders},
  journal={Journal of Paleontology},
  pages={1054 - 1064}
  • P. Ward, W. Saunders
  • Published 1 November 1997
  • Biology, Environmental Science
  • Journal of Paleontology
Living ectocochliate cephalopods have long been thought to be restricted to a single genus, Nautilus Linnaeus, 1758, comprising five or six extant species. The shells of two species, N. scrobiculatus Lightfoot, 1786, and N. perforatus Conrad, 1847, are quite distinct, but no soft-parts were known until 1984, when N. scrobiculatus was seen alive for the first time. Dissections show that significant anatomical differences exist between N. scrobiculatus and other Nautilus species, including… 

Evolutionary Radiation of Present-Day Nautilus and Allonautilus

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A revisited phylogeography of Nautilus pompilius

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Systematics of Cephalopods

Cephalopoda is an extremely diverse class of mollusks that has been evolving since the Cambrian and diverged into Nautiloidea and Coleoidea in the mid-Palaeozoic; the relationships among orders of Decapodiformes are not well understood, and molecular systematics has failed to provide much resolution.

Descriptions of Nautilus pompilius Linnaeus, 1758 from the Type Area, Ambon, Molucca Islands, and from Sumbawa - Lombok Islands, Indonesia

Live-caught animals from 150–400 m depth off Ambon provide the first morphologic and genetic details on Nautilus pompilius from the type region, including a recently proposed neotype for the type species.

The erroneous distinction between tetrabranchiate and dibranchiate cephalopods

  • Z. Lewy
  • Environmental Science, Geography
  • 2000
The two pairs of gills, which occur in extant nautilids only, are suggested to reflect a minor anatomical modification to improve respiration in low oxygen settings by the duplication of the cephalopod initial single pair of gill structure, and are thus of no taxonomic significance.

Occurrence of a specific dual symbiosis in the excretory organ of geographically distant Nautiloids populations.

This study confirms the specificity of this dual symbiosis involving the presence of betaproteobacteria and spirochaete symbionts on a very wide geographical area and sheds further light on Nautiloids excretory organ as an innovative system of interaction between bacteria and cephalopods.

The Mitochondrial Genome of Allonautilus (Mollusca: Cephalopoda): Base Composition, Noncoding-Region Variation, and Phylogenetic Divergence

A phylogeny of 24 extant cephalopods indicates that there is less molecular divergence between Allonautilus and Nautilus than there is among congeneric species of Octopus and Sepia.

Late Cretaceous Octobrachiate Coleoid Lower Jaws from the North Pacific Regions

Abstract Eight well-preserved cephalopod jaw fossils were discovered from the Upper Cretaceous (Santonian and Campanian) deposits of Vancouver Island, Canada, and Hokkaido, Japan. They occur


  • Biology
olluscs include some of the best-known invertebrates; almost everyone is familiar with snails, clams, slugs, squids, and octopuses. Molluscan shells have been popular since ancient times, and some



Genetic divergence and geographic diversification in Nautilus

DNA sequence analysis indicates that there are three geographically distinct clades consisting of western Pacific, eastern Australian/Papua-New Guinean, and western Australian/Indonesian forms, and morphologically and genetically distinct species Nautilus scrobiculatus falls outside the three geographically recognized assemblages.

Nautilus : the biology and paleobiology of a living fossil

Nautilus Studies—The First Twenty-Two Centuries -- Nautilus Studies—The First Twenty-Two Centuries -- The Ancestry of the Genus Nautilus -- The Ancestry of the Genus Nautilus -- Nautilus and Its

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Is Nautilus a Living Fossil

  • P. Ward
  • Environmental Science, Geography
  • 1984
The two quotes above are representative of the controversy concerning the age of Nautilus, the last externally shelled cephalopod. If we accept the first age estimate, we would have to include

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Rates of Evolution and the Notion of "Living Fossils"

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Geometric analysis of shell coiling; general problems

Among the shells of invertebrates that exhibit spiral growth, differences in form can be expressed by differences in geometric parameters. If three parameters are considered at a time, the spectrum