Biarmosuchus would seem to represent one of the most primitive of the Biarmosuchia, and could be taken as a good generalized model for the other, mostly later, forms. This genus is abundantly represented, but most of the specimens remain inadequately prepared and have not been used for an anatomical and functional analysis. Such details as the configuration of the palatines are unknown, as well as numerous characteristics of the postcranial skeleton. It may be that several taxa are represented, but in the present state of our knowledge, it is not possible to define them.
Biarmosaurus antecessor is based on a larger (206 mm as opposed to 153 mm) skull than the holotype, representing a mature individual. This animal is similar in size to
Phthinosuchus, but opinions differ as to how distinct the two forms are. The large size of the orbit (eye socket) constitutes the most notable difference. Three monospecific genera,
Biarmosuchus,
Eotitanosuchus, and
Ivantosaurus, are known from the Ocher locality, differing dramatically in size. Ivakhnenko (1999) argues that these represent different growth stages of the same animal but it is now believed the three forms appear to be quite distinct. ==See also==