Orthaspidoceras is an extinct ammonoid cephalopod genus belonging to the family Aspidoceratidae. These nektonic carnivores lived during the Jurassic period, Kimmeridgian age.
Shells of Orthaspidoceras are medium or large-sized, with a diameter reaching about . These shells are relatively involute and thick, with a quadrate-rounded or depressed whorls. The ornamentation consists of a row of coarse tubercles and fine streaks.
Jurassic deposites of Italy, Mexico, Switzerland and Yemen.