New insights on feeding habits of Kolpochoerus from the Shungura Formation (Lower Omo Valley, Ethiopia) using dental microwear textures
Résumé
During the Neogene and the Quaternary, African suids show dental morphological changes considered to reflect adaptations to increasing specialization on graminivorous diets, notably in the genus Kolpochoerus. They tend to exhibit elongated third molars and some degree of hypsodonty, suggesting increasing consumption of abrasive grasses. However, the most significant morphological changes are not synchronous with the increased consumption of C4 plants, such as graminoids. To date, only a few studies have applied dental microwear texture analysis (DMTA), which provides information on the mechanical properties of the diet, to specimens of Kolpochoerus. In addition, none has yet focused on specimens from the Shungura Formation (Lower Omo Valley, Ethiopia), which is the most complete Late Pliocene to Early Pleistocene record in eastern Africa.We studied dental microwear textures (DMT) in four genera of extant suids with contrasting diets: the herbivores Phacochoerus and Hylochoerus, and the omnivores Potamochoerus and Sus. Our results show that their DMT reflect their different feeding habits. We then studied the DMT of 68 Kolpochoerus specimens from the Shungura Formation and dating from about 2.9 Ma to 1.0 Ma. Their DMT differ from extant suids, but some similarities with Phacochoerus are observed. In line with previous studies, we propose that their DMT reflect a high consumption of herbaceous plants (graminoids and non-graminoids), with preferences for young, low-abrasive grasses.