A
fossil of
Thrissops formosus, a member of the extinct fish genus
Thrissops that lived during the
Jurassic and
Cretaceous periods.
Thrissops were fast predatory fish, about 24 inches (60 cm) long, that fed on other
bony fish. They had a streamlined body with a deeply cleft tail and only very small
pelvic fins.
Photo: H. Zell