Fossils of euzaphlegids are found from Paleocene to Late Miocene-aged marine strata of Europe, the Caucasus Mountains,[2] India, Iran, Turkmenistan, Italy,[1] and Southern California.

[4] The sharp teeth and mackerel-like forms strongly suggest that the euzaphlegids were predators, verified by the remains of numerous extinct deep sea smelt, Bathylagus, and herring, Xyne grex, found within the stomachs of several specimens of Thyrsocles and Euzaphleges.

Later, the genus Palimphyes, whose 10 species are found in Paleogene Tethys and Paratethys strata from the Swiss Alps, the Carpathians, Caucasus, Iran, India and Turkmenistan,[1] was placed within Euzaphlegidae as the subfamily Dipterichthyinae (named after a junior synonym, Dipterichthys).

Euzaphlegids would survive in deep water habitats of what is now Southern California, where they became mesopelagic predators ecologically similar to their relatives, the snake mackerels and escolars.

[3] This cooling event, coupled with the survival of the scombrids in southern Californian marine ecosystems, also helped prevent gempylids from replacing the Euzaphlegidae during the Pliocene or Pleistocene.