Phragmoteuthida

Phragmoteuthida
Temporal range: Permian - Jurassic
Phragmoteuthis conocauda
Scientific classification
Kingdom:Animalia
Phylum:Mollusca
Class:Cephalopoda
Clade:†Belemnoidea
Order:†Phragmoteuthida
Jeletzky in Sweet, 1964
Families

See text.

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

Diagnosis

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 from the Jurassic of Dorset, England. Notes 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.

Classification

  • Order Phragmoteuthida

References

  1. 1 2 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.
  • D.T. Donovan 2006. Phragmoteuthida (Cephalopoda: coleoidea) from the Jurassic of Dorset, England. Palaeontology Vp; 49 Issue 3 pp 673 -684 May 2006.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.