Lewisuchus is a
genus of
archosaur that lived during the
Middle Triassic (
Ladinian); it was a
silesaurid dinosauriform, a member of the group of reptiles which led to the dinosaurs.
Lewisuchus was about one meter long. Fossils have been found in
Argentina. Some of the fossils originally assigned to
Lewisuchus have since been moved to other genera, and the remaining portions closely resemble those of
Pseudolagosuchus. A 2010 study in the Journal
Nature indicated that the two may be
synonymous. They were approximately the same size and came from the same locality and strata, but the fossil material is fragmentary and there is very little overlapping material. Since
Lewisuchus was described 15 years before
Pseudolagosuchus, if it is shown the two are synonymous (through the discovery of additional fossils) the name
Lewisuchus would have priority.