Clearing and staining techniques have been present since 1897, However, their use in anatomical studies of adult micromammals has been limited. When using such techniques in combination with allometric method, it is possible to study articulated skeletons of micromammals, instead of relying only on the skulls, which is important in morphologically complicated groups as the rodents. Research involving multivariate allometric analysis of postcranial skeleton of rodents has been limited and confined to specific items. In this study, we analyzed and compared the morphometry of the skeleton of Neotomodon alstoni with that of Meriones unguiculatus, Phodopus campbelli and Rattus norvegicus. We applied the double staining and clearing technique in order to determine the morphometric relation between these rodents using sixty skeletal characters. We found that three species share two common correlations and one isometric, with apparent similarities between the morphometry patterns of P campbelli with the ossification pattern described for the related species Mesocricetus auratus. The differences in allometric growth could represent differences in the development stages according to the type of life history for each species. In this analysis we confirmed that both the preparation technique and morphometric analysis method, are simple yet verifiable tools for anatomical and morphological studies. Our results reflect the conditions of ontogenetic development derived from the heterochrony pattern for each species, representing the evolutionary history for this group. Therefore, as this approach continues to be discussed, ongoing research is warranted.

KEY WORDS: Neotomodon; Rodents; Morphology; Staining and clearing technique; Allometry.