[3] Another specimen named UFAC 1272, consisting of a premaxilla and maxilla, was discovered in the nearby Sena Madureia locality of the late Miocene Solimões Formation,[2] in and referred to the species in 1997.

[8] Fragmentary material of Gryposuchus from the Fitzcarrald Arch in the Peruvian Amazon dating back to the late middle Miocene bear a close resemblance to G. colombianus, but differ in rostrum proportions.

Measuring the entire length of the skull from the end of the rostrum to the supraoccipital would result in a much larger size estimate, up to three times as great.

[12] Some skull material also recovered from Peruvian Amazon (Iquitos) in the Pebas Formation of the Middle Miocene,[2] was named as Gryposuchus pachakamue in 2016 by Rodolfo Salas-Gismondi et al.

This dominance was likely due to the fact that Gryposuchus was one of only two freshwater adapted gryposuchines (other than Hesperogavialis),[19] whereas the others (such as Siquisiquesuchus and Piscogavialis) were either primarily estuarine, coastal or marine based predators.

However, at the Miocene/Pliocene boundary, all Gavialoidea and Crocodyloidea (another superfamily colonising in the Miocene) were likely extirpated from South America, with the endemic Caimaninae undergoing a severe reduction in size and diversity as well.

The co-current aridification of the continental interior, and filling of peripheral wetland basins, further restricted the space and food resources of these large, food-intensive specialist crocodilians, and was probably the primary cause of their extinction.