The feature that traditionally united these species under the genus Asiatosuchus is a broad connection or symphysis between the two halves of the lower jaw.

Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of fossil specimens suggest that only the first named species of Asiatosuchus, A. grangeri from the Eocene of Mongolia, belongs in the genus.

depressifrons are still considered valid species, but they do not form an evolutionary grouping with A. grangeri that would warrant them being placed together in the genus Asiatosuchus.

An overbite is a primitive feature among crocodyloids because modern crocodiles have teeth in the upper and lower jaws that interlock with each other with little overlap.

Asiatosuchus can be distinguished from other early crocodyloids by its extended mandibular symphysis, the region where the two halves of the lower jaws connect.

It was named on the basis of a lower jaw and pieces of a skull from the Irdin Manha Formation of Inner Mongolia, China, which dates back to the Middle Eocene.

Mook named Asiatosuchus grangeri after Walter W. Granger, a vertebrate paleontologist with the American Museum of Natural History and a member of the expedition.

[4] Mook thought that Asiatosuchus grangeri was closely related to species of Crocodylus (modern crocodiles) but different in having 17 teeth in each half of the lower jaw and a splenial bone that does not form part of the mandibular symphysis.

[2] The German remains came from the Messel Pit quarry, a fossil site that has preserved many forms of life that inhabited a series of anoxic lakes and surrounding subtropical forests during the Eocene.

The naming of this new species was based on a skull found in the Sables du Castrais Formation, France that dates back to the Early Eocene.

A. volgensis and A. zajsanicus were regarded as nomina dubia by Angielczyk and Gingerich (1998) because they are based on fossil specimens that preserve very little anatomical detail.

[2] The crocodyloid species "Crocodylus" monsvialensis was named from Early Oligocene deposits in Monteviale, Italy in 1914 and reassigned to Asiatosuchus in 1993, although subsequent authors questioned this referral and considered it synonymous with Diplocynodon ratelii.

The fossil was found in the Middle Eocene Drazinda Formation, a marine deposit which has also preserved the remains of archaeocete whales.

The presence of a possible specimen of Asiatosuchus in marine deposits suggests that these crocodilians could have tolerated prolonged periods of time in the ocean, an ability that would have aided in the dispersal of early crocodyloids across Europe and Asia.

Recent phylogenetic analyses place Asiatosuchus as a basal ("primitive") member of this clade, close to the split between Crocodyloidea and Alligatoroidea, the group that includes living alligators, caimans, and their extinct relatives.

Some phylogenetic analyses have placed "Asiatosuchus" germanicus as the sister taxon or closest relative of a group called Mekosuchinae.

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