Phragmoteuthida
Phragmoteuthida | |
---|---|
Phragmoteuthis conocauda | |
Scientific 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 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
- Family Phragmoteuthididae
- Genus Permoteuthis
- Genus Phragmoteuthis
- "unnamed form"
- Family Rhiphaeoteuthidae
- Genus Rhiphaeoteuthis
- Family Phragmoteuthididae
References
- ^ 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.
- D.T. Donovan 2006. Phragmoteuthida (Cephalopoda: coleoidea) from the Jurassic of Dorset, England. Palaeontology Vp; 49 Issue 3 pp 673 -684 May 2006. [1]