Arctocephalites is an extinct ammonitic cephalopod genus from the Middle Jurassic with a wide northern distribution belonging to the stephanoceratacean family, Cardioceratidae. The inner whorls of the Arctocephalites shell are sharply ribbed but change abruptly to smooth. The such, as characteristic of the family, is complex with large first lateral lobe and well-developed umbilical lobe.