ammonites
Anteridocus bicostatus Cooper and Grant 1976 (lamp shell)

Rhynchonellata - Rhynchonellida - Pontisiidae

Full reference: G. A. Cooper and R. E. Grant. 1976. Permian Brachiopods from West Texas, IV. Smithsonian Contributions to Paleobiology 21:1923-2607

Belongs to Anteridocus according to G. A. Cooper and R. E. Grant 1976

Sister taxa: Anteridocus erugatus, Anteridocus eximius, Anteridocus gongylus, Anteridocus paucicostatus, Anteridocus seminudus, Anteridocus subcarinatus, Anteridocus swallovianus, Anteridocus triangulatus

Type specimen: USNM 152842a, a shell (Articulated shell)

Ecology: stationary epifaunal suspension feeder

Average measurements (in mm): shell 8.03 x 9.73