''Physogaleus'' is a small genus of prehistoric

shark Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimo ...

that lived from the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...

Description

''Physogaleus'' are only known from their fossil teeth and isolated vertebra. It has teeth similar to the modern tiger shark, but smaller. Species of ''Physogaleus'' were originally described as being teeth of extinct tiger shark species in the genus ''Galeocerdo''. Recognition of numerous differences in tooth anatomies of these species with other species of ''Galeocerdo'' lead researchers to erect the genus ''Physogaleus''.Hernandez, C. 2015. Paleobiology of the Mio-Pliocene sharks, with emphasis on the extinct apex predator ''Carcharocles megalodon''. University of Florida. Unpublished Ph.D. Dissertation ''Physogaleus'' teeth are smaller than those of true tiger sharks, lacking the heavy serrations typical of ''Galeocerdo'', are more slender and can be twisted toward the crown. This indicates individuals of ''Physogaleus'' probably had a diet of bony fish, similar to the living sand-tiger shark.

References

Eocene sharks Prehistoric fish of Africa {{Paleo-shark-stub