Jaxtasuchus is an extinct genus of armored doswelliid archosauriform reptile known from the Middle Triassic (Ladinian stage) of the Erfurt Formation in Germany.
Like other doswelliids, members of the genus were heavily armored, with four longitudinal rows of bony plates called osteoderms covering the body.
Jaxtasuchus is the first doswelliid known from Europe and is most closely related to Doswellia from the Late Triassic of the eastern United States.
[1] Fossils of Jaxtasuchus have been found in the Lower Keuper of southern Germany, which dates back to the end of the Middle Triassic.
The osteoderms of Jaxtasuchus were originally interpreted as the dermal bones of temnospondyl amphibians and later as the plates of aetosaur reptiles.
The only other archosauriforms currently known from the Lower Keuper are Zanclodon laevis, which is known from a jaw fragment and several teeth, and Batrachotomus kupferzellensis, a large pseudosuchian archosaur that is known from several skeletons.
[1] The holotype specimen, SMNS 91352, is a mostly complete skeleton missing the head and neck, which was found at the Schumann quarry of Eschenau (part of Vellberg).
The type species J. salomoni is named after Hans Michael Salomon, who discovered the holotype specimen and donated it to the Staatliches Museum für Naturkunde Stuttgart where it is now housed.
They were oval shaped in cross-section, and uniquely lacked serrations while also having pronounced longitudinal ridges along their labial and lingual (cheek- and tongue-facing) sides.
This contrasts with Doswellia, which has a smaller and stouter postorbital bone and a lower temporal fenestra which has been completely closed up, giving it a euryapsid skull.
Most of the osteoderms were roughly textured by a radiating web of ridges and pits, although they also had a flat, smooth front edge which was thinner than the rest of the plate.
[1] Despite the heavy armor of the torso, the limb bones of Jaxtasuchus were fairly small and slender, with the hindlimbs longer than the forelimbs.