Orthaspidoceras

Orthaspidoceras is an extinct ammonoid cephalopod genus belonging to the family Aspidoceratidae. These nektonic carnivores lived during the Jurassic period, Kimmeridgian age.

Description
Shells of Orthaspidoceras are medium or large-sized, with a diameter reaching about 20 - 25 cm. 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.

Distribution
Jurassic deposites of Italy, Mexico, Switzerland and Yemen.