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Phragmoteuthida

From Wikipedia, the free encyclopedia

Phragmoteuthida
Temporal range: Permian - Jurassic
Comparation of hard parts of Phragmoteuthida, Belemnitida and Diplobelida
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Superorder: Belemnoidea
Order: Phragmoteuthida
Jeletzky in Sweet, 1964
Families

See text.

Phragmoteuthida is an order of extinct coleoid cephalopods[1] characterized by a fan-like teuthoid pro-ostracum attached to a belemnoid-like phragmocone.

Diagnosis

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Jeletzky[1] characterized phragmoteuthids as having a large tripartite, fanlike pro-ostracum forming the longest portion of the shell, attached to about three-quarters of the circumference of a comparatively small breviconic phragmocone with short camerae and superficially belemnitid-like siphuncle, an absent or much reduced rostrum at the apical part of the phragmocone, belemnite-like arm hooks, an ink sack, beaks resembling those of Recent teuthids, and a muscular mantle.

Donovan (2006), gives a similar description for Phragmoteuthis: Phragmocones as having an apical angle of between 20 and 30 degrees, and relatively few chambers compared with belemnoids; a multi-layered conotheca, thick-walled siphuncle, and a long, three-lobed pro-ostracum as in the Triassic species. Arms are short and bear pairs of slightly curved hooks.[2]

Classification

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References

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  1. ^ a b Doguzhaeva, L. (2002). "Adolescent bactritoid, orthoceroid, ammonoid and coleoid shells from the Upper Carboniferous and Lower Permian of the South Urals" (PDF). Abhandlungen der Geologischen Bundesanstalt. 57: 9–55.
  2. ^ Donovan, D.T. (May 2006). "Phragmoteuthida (Cephalopoda: coleoidea) from the Jurassic of Dorset, England". Palaeontology. 49 (3): 673–684. doi:10.1111/j.1475-4983.2006.00552.x. S2CID 128893474.{{cite journal}}: CS1 maint: date and year (link)