Skull mechanics and functional morphology of Brasliodontidae, the sister clade to mammaliaforms.

SALCIDO, CHARLES; RAYFIELD, EMILY; GILL, PAMELA; AGUSTIN MARTINELLI

Simposio; Progressive Palaeontology 2018 in Manchester; 2018

The Late Triassic vertebrate assemblages of the Santa Maria Supersequence in Brazil have yieldedmany specimens of cynodont therapsids including members of the clade Brasilodontidae. Recentphylogenetic analyses have placed this clade as the sister clade to Mammmaliaformes. While thecranial anatomy of brasilodontids has been described in some detail, we understand little of the skullmechanics of their members, and how this contributes to the functional evolution ofmammals. Here, the skulls of three putative species referred to brasilodontids Brasilodonquadrangularis, Brasilitherium riograndensis, and Minicynodon maieri are studied in order to (i) comparetheir functional morphology and biomechanics; and (ii) to determine similarities and differences tothe Early Jurassic mammaliaforms Morganucodon watsoni and Kuehneotherium praecursoris and (iii)to infer any additional information on the proposed ontogenetic relationship of each taxon, whichwere inferred as representing a single taxonomic unit. At this stage, we compare the results ofsecond moment of area and finite element analysis of the mandibles of Brasilodon and Minicynodon toeach other and those of Morganucodon and Kuehneotherium from a previous study.