''Jeletzkya douglassae'' is a fossil belemnoid from the early

Pennsylvanian Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the International Commission on Stratigraphy, ICS geologic timesc ...

Mazon Creek The Mazon Creek fossil beds are a conservation ' found near Morris, in Grundy County, Illinois. The fossils are preserved in ironstone concretions, formed approximately in the mid- Pennsylvanian epoch of the Carboniferous period. These concr ...

lagerstätten and represents the earliest known

crown-group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...

. Non-mineralized anatomy is preserved and comprises ten hooked

tentacles In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

and a

radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...

. It is too poorly understood for assignment to any particular cephalopod taxon. ''J. douglassae'' is 14 mm long.

References

Carboniferous cephalopods Cephalopod genera Carboniferous animals of North America {{paleo-cephalopod-stub