Comparing the Evolution of the Extinct, Endemic Carnivorous Mammals of South America and Africa (Sparassodonts and Hyaenodonts)

Sparassodonts[aut]Sparrasodonta (sparassodonts) in South AmericaSouth America and hyaenodonts in Africa present an interesting test case for comparing the evolutionary trajectories of ecologically similar clades on once isolated continents. Despite being distantly related within Mammalia (sparassodonts[aut]Sparrasodonta (sparassodonts) are metatherians[aut]Metatheria (metatherians) and hyaenodonts are eutherians[aut]Eutheria (eutherians)), they share many adaptationsDiet/dietaryadaptations for a carnivorous dietCarnivore/carnivorousdiet, including an entire molar row modified into carnassials. Using data from the NOW database, we find that both groups became increasingly carnivorous during the Cenozoic, though only hyaenodonts showed a corresponding increase in body sizeBody mass/sizeincrease. This difference may be due to different reproductive strategiesReproductive strategy in theReproductive strategyLife-history strategy two groups. Further comparisons between these groups and comparisons with modern carnivorans[aut]Carnivora (carnivorans) are necessary to determine the degree to which parallels and differences in the evolutionary trajectories of all three are related to the number of pairs of carnassialized teethCarnassialcarnassialized teeth (i.e., several versus only one) and the adaptability of the distal tooth row.