Thadeosaurus

Thadeosaurus is an extinct genus of diapsid reptile belonging to the family Younginidae. Fossils have been found in the Lower Sakamena Formation (Sakamena Group) of the Morondava Basin, Madagascar in 1981, and date to the late Permian to the early Triassic period.
Description.
"Thadeosaurus" was a lizard-like animal, with a remarkably long tail that comprised about two thirds of the animal's total length of . It also had long toes, especially on the hind legs, which would have given it a powerful stride, since the toes would still touch the ground while the foot was being raised. Combined with a strong breast bone to increase the strength in the forelimbs, this means that "Thadeosaurus" was probably a good runner.
Below is a cladogram from Reisz "et al." (2011) showing the phylogenetic position of "Thadeosaurus" among other early diapsids: