ammonites
Anteridocus swallovianus Shumard 1859 (lamp shell)

Rhynchonellata - Rhynchonellida - Pontisiidae

Alternative combinations: Camerophoria swalloviana, Pugnax swallowiana

Full reference: B. F. Shumard. 1859. Notice of fossils from the Permian strata of Texas and New Mexico obtained by the United States expedition under Capt. John Pope, for boring artesian wells along the 32nd parallel, with descriptions of new species from these strata and the Coal Measures of that region. Transactions of the Academy of Science of St. Louis 1:387-402

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

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

Ecology: stationary epifaunal suspension feeder

Average measurements (in mm): shell 8.06 x 8.65, valve 12.7 x 14.8