Prionomyrmex is an extinct genus of bulldog ants in the subfamily Myrmeciinae of the family Formicidae. It was first described by Gustav Mayr in 1868, after he collected a holotype worker of P. longiceps in Baltic amber. Three species are currently described, characterised by their long mandibles, slender bodies and large size. These ants are known from the Eocene and Late Oligocene, with fossil specimens only found around Europe. It is suggested that these ants preferred to live in jungles, with one species assumed to be an arboreal nesting species. These ants had a powerful stinger that was used to subdue prey. In 2000, it was suggested by Cesare Baroni Urbani that the living species Nothomyrmecia macrops and a species he described both belonged to Prionomyrmex, but this proposal has not