9.10: A Dead End - Genus Paranthropus
- Page ID
- 62349
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The australopiths had a relatively slender build and teeth that were suited for soft food. In the past several years, fossils of hominins of a different body type have been found and dated to approximately 2.5 million years ago. These hominins, of the genus Paranthropus, were muscular, stood 1.3-1.4 meters tall, and had large grinding teeth. Their molars showed heavy wear, suggesting that they had a coarse and fibrous vegetarian diet as opposed to the partially carnivorous diet of the australopiths. Paranthropus includes Paranthropus robustus of South Africa, and Paranthropus aethiopicus and Paranthropus boisei of East Africa. The hominins in this genus went extinct more than 1 million years ago and are not thought to be ancestral to modern humans, but rather members of an evolutionary branch on the hominin tree that left no descendants.
The Black Skull or KNM-WT (Kenya National Museum – West Turkana) 15000 was a magnificent find. The almost complete skull was stained from manganese. Features include: small brain (~410 cc), long molars, and the degree of prognathism in the lower face.
Because their faces were so broad and their brains so small, they exhibit a high degree of postorbital constriction, i.e., the area of the skull behind the eyes (forehead area) is narrow. Their muscles of mastication were incredibly strong, as evidenced by the sagittal crest running down the midline of their skull where the temporalis muscle originated. These are all adaptations to eating hard, low-quality foods.