Trucidocynodon

Trucidocynodon; Temporal range: Late Triassic, 220 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
	Skull
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Clade:	Therapsida
Clade:	Cynodontia
Family:	†Ecteniniidae
Genus:	†Trucidocynodon; Oliveira et al. 2010
Species:	†T. riograndensis
Binomial name
	†Trucidocynodon riograndensis; Oliveira et al. 2010

Life restoration

Trucidocynodon is an extinct genus of ecteniniid cynodonts from Upper Triassic of Brazil.^[1] It contains a single species, Trucidocynodon riograndensis. Fossils of Trucidocynodon were discovered in Santa Maria Formation outcrops in Paleorrota geopark Agudo. T. riograndensis was similar to Ecteninion lunensis from the Upper Triassic Ischigualasto formation of Argentina, but differed in several respects, including its larger size. It is known from a nearly complete holotype skeleton as well as a referred skull. The holotype skeleton had an estimated length of 1.2 meters (4 feet), while the referred skull was 17% larger than that of the holotype. Trucidocynodon is considered one of the largest known carnivorous cynodonts from the Triassic, as well as one of the largest probainognathians in the entire Mesozoic.^[1]^[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.^[3]