Youngina? SAM K7710 is the oldest and most primitive specimen of Youngina. Originally considered a den of juveniles (without phylogenetic analysis), this specimen is small because it is primitive, derived from a sister to Spinoaequalis and basal to Prolacerta (and all protorosaurs) and basal to the rest of the Youngina and Youngoides specimens.

Smith, RMH and Evans SE 1996. New material of Youngina: evidence of juvenile aggregation in Permian diapsid reptiles. Palaeontology, 39 (2):289–303.

wiki/Youngina