The short tusks found in all known heterodontosaurids strongly resemble tusks found in modern musk deer, peccaries and pigs. In many of these animals (as well as the longer-tusked walrus and Asian elephants), this is a sexually dimorphic trait, with tusks only found in males. The type specimen of "Abrictosaurus" lacks tusks and was originally described as a female. While this remains possible, the unfused sacral vertebrae and short face indicate that this specimen represents a juvenile animal. A second, larger specimen originally proposed to belong to "Abrictosaurus" clearly possesses tusks, which was used to support the idea that tusks are found only in adults, rather than being a secondary sexual characteristic of males. These tusks could have been used for combat or display with members of the same species or with other species. The absence of tusks in juvenile "Abrictosaurus" could also be another characteristic separating it from other heterodontosaurids as well, as tusks are known in juvenile "Heterodontosaurus". Other proposed functions for the tusks include defense and use in an occasionally omnivorous diet. However, this specimen was alternatively reassigned to "Lycorhinus" by Sereno in 2012, which is already known to have possessed tusks and therefore their absence in "Abrictosaurus" may not have been a result of age.