Fossils were first described from the Bridger Formation by American paleontologist Othniel Charles Marsh in 1871.

[2] The known specimen of "Crocodylus" affinis is a skull found at Grizzly Buttes, Wyoming, measuring 13 inches in length on the upper surface.

Other Bridger species such as Crocodylus clavis and Brachyuranochampsa zangerli have been synonymized with "C." affinis.

[4][5] A 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data established the inter-relationships within Crocodilia,[6] which was expanded upon in 2021 by Hekkala et al. using paleogenomics by extracting DNA from the extinct Voay.

[7] The below cladogram shows the results of the latest studies, which placed "C." affinis outside of Crocodyloidea, as more basal than Longirostres (the combined group of crocodiles and gavialids).