Teudopseina Explained

The Teudopseina is a clade of stem-octopods that first evolved in the Toarcian,[1] considered the largest clade of gladius-bearing coleoids in the Mesozoic. Up to five families are known, among which the Trachyteuthidae, Trachyteuthis in particular, were the most abundant.[2]

Description

The Teudopseina can be united by five primary traits. These are the presence of a gladius, 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.[2] Members of the superfamily Muensterelloidea 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.[3]

Taxonomy

The current consensus is that the Teudopseina forms a stem-group of the Octopoda.[4] [5] Certain taxa, such as Enchoteuthis, have sometimes been classified as either relatives of giant squids or vampire squids.

Notes and References

  1. 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.
  2. http://tolweb.org/Teudopseina/140241 Tree of Life Project: Teudopseina
  3. 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.
  4. Haas, W. 2002. The evolutionary history of the eight-armed Coleoidea. Abhandlungen der Geologischen Bundesanstalt 57: 341-351.
  5. "Fuchs, D. 2009. Octobrachia - a diphyletic origin? Berliner Paläobiologische Abhandlungen 10: 182-192."