Phylogenetic analysis suggests it either being a sister species to the extant, widespread Eurasian vulture genus Gyps or as a more basal member of the subfamily.

The identification of Cryptogyps as a vulture solves a longstanding mystery about the lack of specialized lineages of large scavenging birds in Australia despite being present on every other continent aside from Antarctica.

It was initially described as “Taphaetus” lacertosus by Charles Walter De Vis in 1905 based on the lower part of a humerus and a quadrate bone of Middle-Late Pleistocene age, found around Kalamurina in South Australia.

In 1974 Gerard Frederick van Tets suggested that "T." lacertosus was a member of the genus Icthyophaga (now synonymous with Haliaeetus) and designated the humerus as the lectotype before later placing the species in the subfamily Gypaetinae, which at the time contained all old-world vultures.

Aside from the type material, fossils of indeterminate Pleistocene age were discovered in the Wellington Caves (New South Wales) and Nullarbor Plain (Western Australia).

[2] Multiple different approaches were taken to determine the mass of Cryptogyps, with values derived from the humeral articular facet length of the coracoid and the shaft width resulting in an estimated weight of 11–12 kg (24–26 lb).

[7] The phylogenetic analysis conducted following the description of the second species of Dynatoaetus mirror the results of Mather's prior work, finding Cryptogyps as nesting just outside the modern aegypiine vultures while also strengthening this conclusion through the new material.

It is thus likely that Cryptogyps were primarily scavengers, feeding upon dead or dying Australian megafauna and at times traveled great distances while searching for carrion.

[4] Assuming that the size of this vulture correlates with its general feeding preference, as observed in its modern relatives, Cryptogyps may have been a "gulper" or "ripper" type scavenger.

While nothing conclusive can be said about the specifics of its behavior, the hypothesis that Cryptogyps is related to extant griffon vultures could mean that they at times gathered in large numbers.

In addition to the native marsupials like thylacines and Sarcophilus as well as monitor lizards,[4] the contemporary Dynatoaetus was a notably larger bird and, assuming that it behaved in a similar fashion to the extant wedge-tailed eagle, may have not been above scavenging when the opportunity presented itself.

The extinction of Cryptogyps is thought to have allowed the wedge-tailed eagle to more easily exploit this resource and become Australia's primary scavenging bird species given the lack of specialised competition.