The shape of its limbs suggests that it may have been an agile, scansorial climber, and could have hunted relatively large prey thanks to its elongate, flattened upper canines.

However, due to its more primitive morphology as evidenced by Salesa et al. in 2002 with an in-depth description of its anatomy, Promegantereon ogygia is believed to be its own genus and species and therefore should remain separate from Paramachairodus.

[4] Promegantereon seemed to prefer open woodland habitat, as evidenced by finds at Cerro de los Batallones, which is a fossil deposit of Vallesian age.

Such herbivores that it could hunt would have included horses like Hipparion, young of the hornless rhinoceros Aceratherium and the proboscidean Tetralophodon, the suid Microstonyx, and possibly the calves of silvatherid giraffes and boselaphine antelopes.

Promegantereon would have competed for such prey with the amphicyonid Magericyon, fellow machairodonts Machairodus and Paramachairodus, the bear Indarctos, and the small hyenid Protictitherium.