Phragmoteuthida
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Phragmoteuthida is an order of extinct
coleoid Subclass (biology), Subclass Coleoidea, or Dibranchiata, is the grouping of cephalopods containing all the various taxa popularly thought of as "soft-bodied" or "shell-less" (i.e., octopuses, squid and cuttlefish). Unlike its extant sister group, ...
cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...
s characterized by a fan-like teuthoid pro-ostracum attached to a belemnoid-like phragmocone.


Diagnosis

Jeletzky 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 ''Phragmoteuthis'' is a genus of extinct coleoid cephalopod known from the late Triassic to the lower Jurassic. Its soft tissue has been preserved; some specimens contain intact ink sacs, and others, gills. It had an internal phragmocone and unk ...
'': 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 ''Permoteuthis'' is a genus of belemnite, an extinct group of cephalopods. See also * Belemnite * List of belemnites This list of belemnite genera is an attempt to create a comprehensive listing of all genera that have ever been included in ...
'' ***Genus †''
Phragmoteuthis ''Phragmoteuthis'' is a genus of extinct coleoid cephalopod known from the late Triassic to the lower Jurassic. Its soft tissue has been preserved; some specimens contain intact ink sacs, and others, gills. It had an internal phragmocone and unk ...
'' ***"unnamed form" **Family † Rhiphaeoteuthidae ***Genus †'' Rhiphaeoteuthis''


References

{{Taxonbar, from=Q7188058 Prehistoric cephalopod orders Belemnoidea Permian first appearances Jurassic extinctions