Allodesmus is an extinct genus of pinniped from the Miocene and related to the genus Desmatophoca. It measured about 8 feet (2.4 m) long and weighed 800 pounds (360 kg). Allodesmus had the specific anatomical features found in modern polygynous pinnipeds: sexual dimorphism, strong canines for fights between bulls and teeth with well-defined growth zones, a result from periodic fasting (in order to defend their harem, males would not take to the sea to feed during the breeding season).