Diet of Theropithecus from 4 to 1 Ma in Kenya

Abstract

Theropithecus was a common large-bodied primate that cooccurred with hominins in many Plio-Pleistocene deposits in East and South Africa. Stable isotope analyses of tooth enamel from T. brumpti (4.0-2.5 Ma) and T. oswaldi (2.0-1.0 Ma) in Kenya show that the earliest Theropithecus at 4 Ma had a diet dominated by C 4 resources. Progressively, this genus increased the proportion of C 4 -derived resources in its diet and by 1.0 Ma, had a diet that was nearly 100% C 4 -derived. It is likely that this diet was comprised of grasses or sedges; stable isotopes cannot, by themselves, give an indication of the relative importance of leaves, seeds, or underground storage organs to the diet of this primate. Theropithecus throughout the 4-to 1-Ma time range has a diet that is more C 4 -based than contemporaneous hominins of the genera Australopithecus, Kenyanthropus, and Homo; however, Theropithecus and Paranthropus have similar proportions of C 4 -based resources in their respective diets.

Stable isotope-based diet reconstructions of Turkana Basin hominins

“…Stable isotope measurements of tooth enamel show that Theropithecus was a heavy C 4 consumer by 4 Ma, with ca. 65% C 4 resources contributing to the diet (58). Throughout the period from 4 to 1 Ma, Theropithecus had a diet that was as much or more C 4 -based than any hominin.…”

Dietary change among hominins and cercopithecids in Ethiopia during the early Pliocene

“…3.8-3.6 Ma (10). The δ 13 C values for the earliest T. brumpti show that it incorporated a large component of C 4 resources in its diet (21). The δ…”

“…C values from T. oswaldi that are younger than 2.0 Ma in Turkana, from Olorgesailie in Kenya, and from Swartkrans, Makapansgat, and Sterkfontein in South Africa (18,(21)(22)(23)(24) (Fig. 2).…”

Paleobiology and Behavior

“…The carbon (C) and oxygen (O) isotopes in enamel are most commonly studied, with the ratio of 18 O to 16 O providing a complex environmental signal and 13 C/ 12 C ratio indicating the proportion of tropical grasses (C 4 ) versus non-tropical grasses, tree and shrub products (C 3 ), or the animals that ate such vegetation, in the diet. Carbon isotope analysis of T. oswaldi teeth from Pleistocene eastern Africa indicate that its diet was dominated (sometimes near-exclusively) by tropical grasses (Cerling et al 2013) although the diet of T. oswaldi from Sterkfontein in southern Africa contained around 30% C 3 plants (van der Merwe et al 2003).…”