Revis？o diagnóstica para a icnoespécie de tetrápode Mesozóico Brasilichnium elusivum (Leonardi, 1981) (Mammalia) da Forma？？o Botucatu, Bacia do Paraná, Brasil

the brasilichnium elusivum ichnospecies was described for the first time in brazil by leonardi, in eocretaceous (neocomian) continental aeolian deposits from botucatu formation, paraná basin, and it corresponds to trackways of a small sized mammal. the tetrapod ichnofossils studied at the present work were identified and collected at the s？o bento quarry, located in the city of araraquara, s？o paulo state. the purpose of this study is to report some new data diagnosis to b. elusivum, due the occurrence of well preserved samples that could serve as base of comparison with the holotype and first paratype, and allowed to determine the ectaxonic character and the tetradactyly (digits ii-iii-iv-v) in semi-plantigrade condition of the hind footprints. the tetradactyly was also observed in the fore autopodia. the heteropody or the homopody, in the occurrence of mammal ichnofossils, was interpreted as the result of preservational conditions associated to distinctive locomotor responses of the same animal during its dislocation across the sand dunes of the botucatu paleodesert.