Meeting Abstract
The effects exerted by predatory mammals have long been recognized for their role in shaping community structure, but what factors drive the evolution of carnivore guilds? Most analyses addressing this question have focused on Northern Hemisphere carnivorans, but Australian marsupial predators (dasyuromorphs, hypsiprymnodontids, and extinct thylacoleonids) represent a guild with a separate evolutionary history that may prove valuable in teasing apart phylogentic and ecological effects. Previous comparisons of Australian and Laurasian predators have focused on craniodental data from large-bodied, extant taxa. These analyses support the hypothesis that the two guilds are convergent, possibly indicating the importance of environmental factors in driving carnivore evolution. This analysis was expanded to include small-bodied taxa and postcranial functional indices. These data were used to reconstruct the morphospace occupied by Australian and North American predator guilds, both Recent and Pleistocene, in order to test the hypothesis that the two are convergent and shaped primarily by abiotic factors. While some overlap exists among modern taxa, large areas of morphospace were occupied by one guild and not the other. Small mesocarnivores comprise a large portion of the Australian guild, while large hypocarnivores are absent; the opposite is true for North America, possibly indicating that either phylogenetic effects or biotic interactions play an important role in driving predator evolution. The fossil data allow a more direct test of the influence of changing climate on predator guild structure. These data suggest a large degree of change between the Pleistocene and Recent, the implications of which will become clearer with increased sampling and by incorporating paleoenvironmental data.
