24 research outputs found
New infant cranium from the African Miocene sheds light on ape evolution
The evolutionary history of extant hominoids (humans and apes) remains poorly understood. The African fossil record during the crucial time period, the Miocene epoch, largely comprises isolated jaws and teeth, and little is known about ape cranial evolution. Here we report on the, to our knowledge, most complete fossil ape cranium yet described, recovered from the 13 million-year-old Middle Miocene site of Napudet, Kenya. The infant specimen, KNM-NP 59050, is assigned to a new species of Nyanzapithecus on the basis of its unerupted permanent teeth, visualized by synchrotron imaging. Its ear canal has a fully ossified tubular ectotympanic, a derived feature linking the species with crown catarrhines. Although it resembles some hylobatids in aspects of its morphology and dental development, it possesses no definitive hylobatid synapomorphies. The combined evidence suggests that nyanzapithecines were stem hominoids close to the origin of extant apes, and that hylobatid-like facial features evolved multiple times during catarrhine evolution
Systematics and paleobiology of Carnivora and Hyaenodonta from the lower Miocene of Buluk, Kenya
Early Miocene carnivorous mammals from Buluk, Kenya, are described and discussed. Four taxa belonging to Hyaenodonta
and four belonging to Carnivora are identified. Members of Hyaenodonta include Hyainailouros sulzeri, Hyainailouros
cf. napakensis, a third taxon about the size of Leakitherium, represented only by postcranial material, and a fourth
taxon represented by an edentulous jaw, in the size range of Sectisodon. Members of Carnivora include a new species of
Cynelos jitu, which represents the largest species of Cynelos known. The first m2 of Cynelos macrodon is described, and
the differentiation of this species from Cynelos ginsburgi and Cynelos peignei is confirmed. A third carnivoran species is
represented by a mandibular fragment attributed to a viverrid similar to Mioprionodon, and a fourth taxon is represented
by a feliform distal humerus, the size of that of a small cat. An ecomorphological guild structure analysis reveals that
the Buluk carnivore have estimated body sizes spanning from 100 kg. Three very large species (>100 kg), and
another two in the 30–100 kg range are present, while only two taxa are present in the 3–10 kg category. Carnivores in
the 1–3 kg and the 10–30 kg categories are absent. Locomotor pattern could be obtained for only four taxa, and all are
characterized by terrestrial locomotion. A minimum of three dietary classes (insectivorous, carnivorous, scavenging)
are represented. The co-occurrence of multiple very large carnivores is not uncommon in early Miocene faunas, but the
taphonomy of Buluk may also contribute to the favored preservation of larger and terrestrially adapted animals
Middle Miocene Kenyapotamus (Cetartiodactyla, Hippopotamidae) from Napudet, Turkana Basin, Kenya
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