''Plesioteuthis'' is an extinct genus of squids, belonging to the family

Plesioteuthididae Plesioteuthididae is an extinct family of squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoide ...

. This genus was first described in 1859, and its fossils were found in the well-known Solnhofen field in Germany.

Species

Species within this genus include: *''Plesioteuthis prisca'' (the type species) (Rueppel, 1829) † *''Plesioteuthis subovata'' (G.G. Münster, 1846 ) † The ''Plesioteuthis arcuata'' is not considered a member of this genus. Together with its close relatives (including '' Rhomboteuthis'', ''

Dorateuthis ''Dorateuthis'' is a genus of cephalopod with a gladius and soft-part anatomy preserved. Fossils of ''D. syriaca'' are found in Upper Santonian-aged shale of Late Cretaceous Lebanon Lebanon ( , ar, لُبْنَان, translit=lubnān, ) ...

'' and '' Boreopeltis'') this animal has often been considered an archaic relative of the octopus (

Octopodiformes Octopodiformes is a superorder of the subclass Coleoidea, comprising the octopuses and the vampire squid. All living members of Octopodiformes have eight arms, either lacking the two tentacles of squid (as is the case in octopuses) or modifyin ...

) due to the fact that more than eight tentacles have never been found in fossils. However, the structure of the beak of Plesioteuthis resembles that of the

Decapodiformes Decapodiformes is a superorder of Cephalopoda comprising all cephalopod species with ten limbs, specifically eight short arms and two long tentacles. It is hypothesized that the ancestral coleoid had five identical pairs of limbs, and that one ...

Fossil record

Plesioteuthididae - Plesiotheuthis prisca

These squids lived in the Tithonian, Upper Jurassic (Age range from 155.7 to 150.8 million years ago) and their fossils were found in Germany.Sepkoski, Jac
Sepkoski's Online Genus Database
/ref>Paleobiology Database
/ref>

Description

These animals were very similar to the current cuttlefish, but they had a thinner stream-lined body of considerable size. The only "cuttlefish bone" or

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 ...

could reach a length of about . In fossils usually the gladius is crushed or flattened, so as to hide the small stabilizers present towards the back. Traces of the tentacles are often preserved. Next to them sometimes there are traces of the beak and mouth. Some phosphatizations of the soft parts preserve the strong striations on the gladius, on the back of the animal. Rhamphorhynchus eating Plesioteuthis

In the middle of the body there was an organ similar to a button, often preserved in a darker color than the rest of the fossil. This structure was the ink-sack.

Biology

They were fast-moving nektonic carnivores living in lagoons, in shallow subtidal water and reefs.

Bibliography

* Fuchs, D., Klinghammer, A., & Keupp, H. 2007. [file:///C:/Users/ebalo/AppData/Local/Packages/Microsoft.MicrosoftEdge_8wekyb3d8bbwe/TempState/Downloads/njgpa_Band_245_Heft_2_p239-252_Taxonomy_morphology_and_phylogeny_of_plesioteuthidid_coleoids_from_the_Upper_Jurassic_Tith%20(1).pdf Taxonomy, morphology and phylogeny of plesioteuthidid coleoids from the Upper Jurassic (Tithonian) Plattenkalks of Solnhofen.] Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 245(2): 239-252. *Klug, C; Schweigert, G; Dietl, G (2010). A new Plesioteuthis with beak from the Kimmeridgian of Nusplingen (Germany). Ferrantia, 59:73-77.

References

Note: This article has been expanded using material based on a translation of an article from the Italian Wikipedia.{{Taxonbar, from=Q20658226 prisca Cephalopod genera