Campyloprion Eastman, 1902 is a chondrichthyan having an arched symphyseal tooth whorl similar to that of

Helicoprion Karpinsky, 1899, but less tightly coiled. The holotype of Campyloprion annectans Eastman, 1902,

the type species of Campyloprion, is of unknown provenance, but is presumed to be from the Pennsylvanian

of North America. Campyloprion ivanovi (Karpinsky, 1922) has been described from the Gzhelian of Russia.

A partial symphyseal tooth whorl, designated as Campyloprion cf. C. ivanovi, is reported from the Missourian

Tinajas Member of the Atrasado Formation of Socorro County, New Mexico, USA. Partial tooth whorls from

the Virgilian Finis Shale and Jacksboro Limestone Members of the Graham Formation of northern Texas, USA,

are designated as Campyloprion sp. Two partial tooth whorls from the Gzhelian of Russia that were previously

referred to C. ivanovi are designated as Campyloprion cf. C. annectans. The age of Toxoprion lecontei (Dean,

1898), from Nevada, USA, is corrected from the Carboniferous to the early Permian. An alternative interpretation

of the holotype of T. lecontei is presented, resulting in a reversal of its anterior-to-posterior orientation. The

genera Helicoprion, Campyloprion, and Shaktauites Tchuvashov, 2001 can be distinguished by their different

spiral angles.