ammonites
Chonetinetes varians Cooper and Grant 1975 (lamp shell)

Strophomenata - Productida - Rugosochonetidae

Full reference: G. A. Cooper and R. E. Grant. 1975. Permian Brachiopods of West Texas, III. Smithsonian Contributions to Paleobiology 19:795-1921

Belongs to Chonetinetes according to P.R. Hoover 1981

Sister taxa: Chonetinetes angustisulcatus, Chonetinetes reversus

Type specimen: USNM 153677a, a shell (Articulated shell)

Ecology: stationary low-level epifaunal suspension feeder

Average measurements (in mm): shell 5.77 x 7.51, valve 6.04 x 10.04