The two Geronticus species differ from other ibises in that they have unfeathered faces and heads, breed on cliffs rather than in trees, and prefer arid habitats to the wetlands used by their relatives.

Their food contains fewer aquatic animals and more terrestrial ones; they are known to gather together and feed on locust swarms, killing many of these notorious pests.

It is known only from a piece of distal right humerus, found at Sansan, France, in Middle Miocene rocks of the Serravallian faunal stage MN 6 (about 12-14 million years ago).

Its remains were found in Early Pliocene deposits near Langebaanweg, South Africa, which date back about five million years.

Contemporaneous with these during the early MN18 faunal stage – about two mya – birds entirely indistinguishable from the modern northern bald ibis inhabited at least Spain, if not the whole western Mediterranean region already.