Trucidocynodon is an extinct genus of ecteniniid cynodonts from the Upper Triassic (Carnian) of Brazil.

Fossils of Trucidocynodon were discovered in outcrops of the Upper Santa Maria Formation in Paleorrota Geopark, Agudo.

[1] T. riograndensis was a carnivorous cynodont closely related to Ecteninion lunensis and Diegocanis eleganus, from the Upper Triassic Ischigualasto Formation of Argentina.

[2] A biomechanical study has argued that Trucidocynodon not only had erect limbs, but that it also possibly had digitigrade forelimbs, being among the first synapsids to show adaptations for cursoriality.

However, it was likely not a specialized runner, unlike ungulates and some other modern cursorial mammals.