 Like many other early archosauromorphs, "Macrocnemus" had a small and low head on the end of a thin neck containing vertebrae with low neural spines and long cervical ribs.Many archosauromorphs with these features have been grouped within the order Protorosauria, although it is debatable whether this order is valid.Features that are common to most "protorosaurs" like "Macrocnemus" include the ankle having a hooked fifth metatarsal attached to elongated limb elements, with tarsal elements with well-ossified proximal and distal ends.