Predicting the diet of extinct bovids using masseteric morphology

Five variables, approximating the size of the masseter muscles on the maxilla, were used for determining dietary adaptations of extinct bovids from the Miocene of Pikermi and Samos (Greece). Grazing extant ruminants were found to have larger masseter muscles; those of browsers are smaller, and mixed feeders show a size in between. The height of the bony protrusion serving as of the origin of masseter superficialis on the maxilla gave the best discrimination among browsers, mixed feeders, and grazers; the origin of the masseter profundus was less discriminatory. It was found that, while some microwear results were congruent with the masseter data, others were not. We evaluate several hypotheses to explain the dissociation of dietary nterpretation based on these variables and conclude that most of the extinct species were mixed feeders. The extinct species Tragoportax amalthea, Tragoportax rugosifrons (Boselaphini), and Gazella capricornis (Antilopini) were probably either mixed feeders or browsers. Pachytragus crassicornis and Pachytragus laticeps (Pseudotragini) were probably mixed feeders.