''Trachyteuthis'' is a genus of fossil

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, a ...

, comprising five species: ''T. hastiformis'', ''T. latipinnis'', ''T. nusplingensis'', ''T. teudopsiformis'', ''T. covacevichi'' and ''T. chilensis''.

Taxonomy

The

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. A ...

placement of ''Trachyteuthis'' is uncertain. Though often assigned to the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

Vampyromorphida Vampyromorphida is an order of cephalopods comprising one known extant species ('' Vampyroteuthis infernalis'') and many extinct taxa. Physically, they somewhat resemble octopus An octopus ( : octopuses or octopodes, see below for var ...

, the discovery of fossilised ''Trachyteuthis'' beaks in the

Upper Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the na ...

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when ...

of Germany suggests a close

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

relation to the Octopoda. It is clear that it does at least belong in the

Coleoidea 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, Nautiloidea, whose ...

. It is thought to be very closely related to ''

Teudopsis ''Teudopsis'' is a genus of the coleoid cephalopod family Teudopsidae, known only from Lower Jurassic gladii. It has been reported from Alberta, Canada and Europe. The life appearance of Teudopsis is probably best inferred by its close relativ ...

''.

Distribution

Fossils are scarce but have been reported from the

Kimmeridge clay The Kimmeridge Clay is a sedimentary deposit of fossiliferous marine clay which is of Late Jurassic to lowermost Cretaceous age and occurs in southern and eastern England and in the North Sea. This rock formation is the major source rock for Nort ...

of the UK; the

Solnhofen Solnhofen is a municipality in the district of Weißenburg-Gunzenhausen in the region of Middle Franconia in the ' of Bavaria in Germany. It is in the Altmühl valley. The local area is famous in geology and palaeontology for Solnhofen lim ...

limestone of Germany, Jurassic deposits in Antarctica, and Oxfordian deposits in Chile.

History

First described in 1773 as the remnants of a fish, ''Trachyteuthis'' was considered comparable to a '' Sepia'' cuttlebone by Rüppell in 1829. A separate genus was erected for the material in 1846 by Meyer. English material discovered in 1855 was termed ''Coccoteuthis latipinnis''; this was later synonymised with the identical Solnhofen deposits. A 2007 survey of museum collection established that there were ground for the erection of three species within the genus.

References

External links

Fischerverlag Jena aus Adolf Naef "Die Fossilen Tintenfische" 1922The Taxonomicon: Order Vampyromorphida
{{Taxonbar, from=Q4119964 Coleoidea Prehistoric cephalopod genera Jurassic cephalopods Solnhofen fauna Fossil taxa described in 1846