sentences:  There seems to be a significant degree of variation between specimens of "M. amarali".Some of this is related to ontogenetic variation, but some may also suggest sexual dimorphism, or even that some of the specimens assigned to this species belong to a different animal.Ontogenetic studies done by Vasconcellos and Carvalho (2005) concluded that during its growth, the skull of "M. amarali" individuals becomes shorter and the skull more resistant, while being laterally compressed.