The Teudopseina is a clade of stem- octopods that first evolved in the

Toarcian The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian ...

,Fuchs, Dirk & Weis, Robert. (2010). Taxonomy, morphology and phylogeny of Lower Jurassic teudopseid coleoids (Cephalopoda). Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen. 257. 351-366. 10.1127/0077-7749/2010/0083. considered the largest clade of

gladius ''Gladius'' () is a Latin word meaning "sword" (of any type), but in its narrow sense it refers to the sword of ancient Roman foot soldiers. Early ancient Roman swords were similar to those of the Greeks, called '' xiphe'' (plural; singular ''xi ...

-bearing coleoids in the Mesozoic. Up to five families are known, among which the Trachyteuthidae, ''

Trachyteuthis ''Trachyteuthis'' is a genus of fossil cephalopod, comprising five species: ''T. hastiformis'', ''T. latipinnis'', ''T. nusplingensis'', ''T. teudopsiformis'', ''T. covacevichi'' and ''T. chilensis''. Taxonomy The taxonomic placement of ''Trac ...

'' in particular, were the most abundant.Tree of Life Project: Teudopseina
''Tree of Life Web Project''. Retrieved 2022-01-15.

Description

The Teudopseina can be united by five primary traits. These are the presence of a

, a reduced, spoon-shaped conus, a median field that is distinctly rounded or pointed anteriorly, weakly curved hyperbolar zones, and lateral fields shorter than the hyperbolar zones. Members of the superfamily

Muensterelloidea Muensterelloidea is a superfamily (or clade) of stem-octopod cephalopods from the Early Jurassic to Late Cretaceous. Two families are currently identified, Muensterellidae, and Patelloctopodidae. The clade is the ancestral group from which moder ...

are characterized by a spoon-shaped section of the gladius, known as the patella. This is believed to be ancestral to the condition present in modern

octopuses An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish ...

.Fuchs, D.; Schweigert, G. (2018). "First Middle–Late Jurassic gladius vestiges provide new evidence on the detailed origin of incirrate and cirrate octopuses (Coleoidea)". PalZ. 92 (2): 203–217. doi:10.1007/s12542-017-0399-8. S2CID 135245479.

Taxonomy

The current consensus is that the Teudopseina forms a stem-group of the Octopoda.Haas, W. 2002. The evolutionary history of the eight-armed Coleoidea. Abhandlungen der Geologischen Bundesanstalt 57: 341-351."Fuchs, D. 2009. Octobrachia - a diphyletic origin? Berliner Paläobiologische Abhandlungen 10: 182-192." Certain taxa, such as '' Enchoteuthis'', have sometimes been classified as either relatives of giant squids or vampire squids.

References

Cephalopods {{Paleo-cephalopod-stub