Wikipedia
Xenocretosuchus
Xenocretosuchus is a genus of probable tritylodont therapsids from the Aptian ( Early Cretaceous) of Siberia, in the Russian Federation. The type species, X. sibiricus, is known only from dental elements, as is X. kolossovi, described in 2008.
The placement of this animal is controversial, but if it is a tritylodont, then it, alongside the contemporary Montirictus, is the latest known non- mammalian synapsid (excepting the perhaps also not-mammalian haramiyidan Avashishta), extending their range to the Early Cretaceous.