Genus: Erpetonyx MODESTO, SCOTT, MacDOUGALL, SUES, EVANS, REISZ, 2015
Etymology: Greek, erpeton, "crawler" and Greek, onyx, "claw."

Species: arsenaultorum MODESTO, SCOTT, MacDOUGALL, SUES, EVANS, REISZ, 2015
Etymology: In honor of the Arsenault family of Prince County, Prince Edward Island, Canada, who discovered and collected the specimen.

Holotype: ROM 55402

Locality: Cape Egmont, southwestern Prince Edward Island, Nova Scotia Province, Canada.

Horizon: Egmont Bay Formation.

Biostratigraphy:

Age: Stephanian, Kasimovian/Gzelian, Upper Pennsylvanian Subperiods, Upper Carboniferous.

Material: A nearly complete skeleton.