The fossil remains from La Barda locality are part of the Paso del Sapo fauna (Chubut, Argentina), the main early Eocene mammal assemblage from west-central Patagonia. Until now, mammals from La Barda had only been recognized by isolated teeth and osteoderms. In this study, postcranial Litopterna remains were identified and segregated into morphological groups, or morphotypes, and their sizes were correlated with litoptern teeth. Morphotype 1 is represented by one astragalus similar to those of post-Deseadan litopterns. Morphotype 2 groups more generalized tibiae, astragali and calcanei which are similar to basal Protolipternidae (e.g., Miguelsoria). The regression model was derived from a known sample of 62 extant and fossil mammals. A 99.7% confidence interval was used to accept or reject a possible relationship between postcranial and dental remains. Dental remains from La Barda have been referred to two species of Asmithwoodwardia (Protolipternidae?). The dental size of both species correlates well with morphotype 2. However, the largest, more derived morphotype 1 astragalus does not appear to be represented in the fauna by any dental remains. This brings to the table the importance of postcranial remains to the comprehension of the diversity of ancient faunas.