Hominins, sedges, and termites: new carbon isotope data from the Sterkfontein
valley and Kruger National Park  • ARTICLE

Journal of Human Evolution, In Press, Corrected Proof, Available online 18
January 2005,

Matt Sponheimer, Julia Lee-Thorp, Darryl de Ruiter, Daryl Codron, Jacqui
Codron, Alexander T. Baugh and Francis Thackeray

http://www.sciencedirect.com/science?_ob=ArticleURL&_aset=B-WA-A-W-DU-MsSAYZW-UUW-AAUYEBYDVU-AAUZCAECVU-YDAUWYDAZ-DU-U&_rdoc=1&_fmt=summary&_udi=B6WJS-4F8TVVT-2&_coverDate=01%2F18%2F2005&_cdi=6886&_orig=search&_st=13&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=8ddbed7bd0c6e1ef05017efcd997f59d

Abstract

Stable carbon isotope analyses have shown that South African australopiths did
not have exclusively frugivorous diets, but also consumed significant
quantities of C4 foods such as grasses, sedges, or animals that ate these
foods. Yet, these studies have had significant limitations. For example,
hominin sample sizes were relatively small, leading some to question the
veracity of the claim for australopith C4 consumption. In addition, it has been
difficult to determine which C4 resources were actually utilized, which is at
least partially due to a lack of stable isotope data on some
purported australopith foods. Here we begin to address these lacunae by
presenting carbon isotope data for 14 new hominin specimens, as well as for two
potential C4 foods (termites and sedges). The new data confirm that non-C3
foods were heavily utilized by australopiths, making up about 40% and 35% of
Australopithecus and Paranthropus diets respectively. Most termites in the
savanna-woodland biome of the Kruger National Park, South Africa, have
intermediate carbon isotope compositions indicating mixed C3/C4 diets. Only 28%
of the sedges in Kruger were C4, and few if any had well-developed rhizomes and
tubers that make some sedges attractive foods. We conclude that although
termites and sedges might have contributed to the C4 signal in South African
australopiths, other C4 foods were also important. Lastly, we suggest that the
consumption of C4 foods is a fundamental hominin trait that, along with
bipedalism, allowed australopiths to pioneer increasingly open and seasonal
environments.

Tom Billings