The functional diversity of marsupial limbs is influenced by both ecology and developmental constraint

Abstract Extant marsupials are less ecologically diverse than placentals, and this is reflected by placentals exhibiting a greater diversity of locomotor modes, including powered flight fully aquatic swimming. One proposed explanation for discrepancy that the development more disparate marsupial forelimbs prevented neonate’s crawl to pouch, which requires precocious forelimb climbing adaptations. To test predictions Developmental Constraint Hypothesis (DCH), we pursue comparative morphometric study on osteological traits mammalian limbs, with an emphasis functional differentiation limbs among modes. We apply multivariate analyses large dataset limb metrics sample mammals, placental limited taxa whose modes exhibited in marsupials. Overall, do not find consistent evidence support DCH. Diprotodontia serves as exception, comparisons their hind supporting Our results suggest developmental constraints may have some degree. Despite this, groups show unexpectedly high levels morphological relative same indicating ecological functions overcome macroevolutionary scale.