[4] Another specimen was discovered in 1971 in the Lower Triassic Fremouw Formation of the Transantarctic Mountains in Antarctica near the McGregor and Shackleton glaciers and described in 1981 by Edwin H. Colbert and James W.
[2][6][7] Ericiolacerta parva was described as a small, fossilized reptile preserved extremely well, despite the skull being partially crushed before it was buried, resulting in distortion of the occipital, otic, and mandibular bones, as well as the loss of part of the premaxillae and zygoma.
[1] The curled position of the skeleton is similar to that assumed by many small mammals when they die, and the displacement of the bones was determined to be as a result of the movement and rotting of still-attached skin.
[2] Both specimens demonstrate a slender dentary with a smooth, rounded ventral margin, which was determined by Huttenlocker & Sidor (2012) to be a compelling apomorphy in diagnosing the species.
Some evidence has suggested Therocephalia may represent a polyphyletic group with some species being more closely related to cynodonts than others, and a uniting clade called Eutheriodontia has been proposed.
Their small size similar to cynodonts may imply a burrowing lifestyle, and unlike other Therocephalians they possessed a secondary palate which may have aided in breathing while eating or in endothermy.
[9][10] The skull also possessed wide, slender zygomatic arches and postorbitals which failed to connect with the zygoma, all features also present in more derived cynodonts which likely aided in muscle attachment for chewing.
[9] Conversely, unlike other Theriodonts Ericiolacerta did not possess a free upstanding coronoid process on the dentary which would also have aided in connecting muscle fibers.
[1][11] The holotype fossil described by Watson had its sternum only partially exposed, making determining if Ericiolacerta had evolved the segmented sternebrae seen in some Gorgonopsians difficult.
[12] This, combined with the long length of its limbs relative to its size implies Ericiolacerta had a more sprawling stance and reptilian gait than more derived cynodonts.
[15][4] It was initially classified within the now-obsolete group Scaloposauria which is now considered to likely represent juvenile forms of various therocephalians, at which point Ericiolacerta was reclassified within Baurioidea.