Plesioturrilites brazoensis
Heteromorph

Late Cretaceous (Early Cenomanian)
Grayson Formation – Washita Group
Bryan County, Oklahoma, USA

55mm Heteromorph. Cephalopod.

Plesioturrilites is a genus of heteromorphic ammonite with a tighly-wound shell similar to Mariella.  It lived during the early part of the Late Cretaceous (roughly 94 to 100 million years ago) and is better known from localities in Texas and Mexico so this is kind of an oddball find.