Elachistosuchus is an extinct genus of neodiapsid reptile, most likely basal archosauromorph, known from the Late Triassic Arnstadt Formation of Saxony-Anhalt, central Germany. It contains a single species, Elachistosuchus huenei, known from a single individual.
Elachistosuchus is an extinct reptile that lived during the Late Triassic period and is believed to be one of the earliest members of the archosaur group.  It's only known from a single individual found in Germany.