Dental micro wear patterns of the sauropod dinosaurscamarasaurusanddiplodocus: Evidence for resource partitioning in the late Jurassic of North America

Resource partitioning can be demonstrated for the two most common sympatric sauropod dinosaurs, Camarasaurus and Diplodocus, from the Upper Jurassic Morrison Formation. The patterns of occurrence of pits, coarse scratches, and fine scratches on the surfaces of teeth of these taxa show that, in general, Camarasaurus ate coarser foodstuffs than did Diplodocus. In contrast with the majority of Camarasaurus teeth belonging to adults, which show evidence of ingestion of coarser foodstuffs, the teeth of juveniles show a pattern of wear similar to that observed on Diplodocus. This suggests that there was dietary overlap between the young of Camarasaurus and adults of Diplodocus, and that dietary divergence occurred when individuals of Camarasaurus achieved adult size.