DOI: 10.5061/dryad.vt4b8gv1f
title: Dataset for: Australopithecus at Sterkfontein did not consume substantial mammalian meat

description: Incorporation of animal-based foods into early hominin diets has been
 hypothesized as a major catalyst of important evolutionary events,
 including brain expansion. However, direct evidence of the onset and
 evolution of animal resource consumption in hominins remains elusive. The
 nitrogen-15-to-nitrogen-14 ratio of collagen provides trophic information
 about individuals in modern and geologically recent (&lt;200,000 year)
 ecosystems, but diagenetic loss of this organic matter precludes studies
 of greater age. In contrast, nitrogen within tooth enamel is preserved for
 millions of years. Here, we report enamel-bound organic nitrogen and
 carbonate carbon isotope measurements of Sterkfontein Member 4 mammalian
 fauna, including seven Australopithecus specimens. Our results suggest a
 variable but plant-based diet (largely C3) for these hominins. Therefore,
 we argue that Australopithecus at Sterkfontein did not engage in regular
 mammalian meat consumption.
description: All data are available in the main text or the supplementary
 materials. Data was analyzed using the Stable Isotopes Bayesian Ellipses
 (SIBER) package (version 2.1.) and the Turner et al. (2010) statistical
 code. The R code is included in the Supplementary Materials. All specimens
 are housed at the Evolutionary Study Institute (ESI) at the University of
 Witwatersrand (Johannesburg, South Africa) under the curatorship of Dr.
 Zipfel. All specimens are accessible to researchers following a fossil
 access application process, which is also managed by Dr. Zipfel.
 Tooth enamel from 43 specimens from Pliocene Sterkfontein Member
 4 mammalian fauna was analyzed for stable carbon
 (δ<sup>13</sup>C<sub>enamel</sub>) and nitrogen
 (δ<sup>15</sup>N<sub>enamel</sub>) isotopes (Table
 S1). Analyzed taxa include <em>Australopithecus</em> sp. (n =
 7), two non-hominin primates Papionini (n = 8) and Cercopithecoides (n =
 1), bovids (n = 12; including browsing (n = 11) and grazing (n = 1) taxa),
 felids (n = 4), canids (n = 5) and hyenids (n = 6). For information on
 location (square and depth within the Sterkfontein deposits), excavation
 details, and authentication see Table S1, for discussion of ages see
 SM. Tooth enamel was drilled on site at the ESI using a
 handheld Dremel with a 0.7 or 0.9 mm diamond ball head (&lt;3,000
 RPM). Sampling was conducted carefully to minimize damage to diagnostic
 morphological features. <em>Australopithecus </em>sp. molars
 from the 1966 to 1996 excavations were sampled and specimens which were
 incomplete or already damaged (e.g., cut in half for previous studies)
 were preferentially chosen. Bulk enamel samples (5 to
 15 mg) were taken longitudinally, between the cervix and cusp of the
 tooth, avoiding the underlying dentin. The surficial enamel was discarded
 to avoid contamination with any adherent sediment and the remaining enamel
 was homogenized. In general, bulk enamel samples integrate approximately
 three months to one year of dietary signal, depending on taxon, tooth type
 and size, and enamel thickness. Images of the seven
 <em>Australopithecus </em>specimens after sampling are shown
 in Fig. S7. The last forming tooth was targeted for analysis whenever
 possible, usually representing adult, post-weaning diet, see section
 “Tooth Formation” in the SM.
 δ<sup>15</sup>N<sub>enamel</sub> of
 mineral-bound nitrogen in tooth enamel was analyzed with the
 “oxidation-denitrification method”, following the protocol published in
 Leichliter et al. (2021) and Moretti et al. (2023). An aliquot of the same
 sample powder was analyzed for stable carbon isotope analyses with the
 “cold trap method” after Vonhof et al. (2020). All measurements were
 performed at the Max Planck Institute for Chemistry (MPIC) in Mainz,
 Germany. For details see SM. Isotope ratios are
 reported on the international scales of Vienna Pee Dee Belemnite (VPDB;
 δ<sup>13</sup>C) or AIR (δ<sup>15</sup>N), where
 δ<sup>13</sup>C or δ<sup>15</sup>N (in ‰) =
 (R<sub>sample</sub>/R<sub>standard</sub>-1) x
 1,000, and R<sub>sample</sub> and
 R<sub>standard</sub> are ratios of heavy to light isotopes of
 the sample and the standard, respectively.
 <strong>References: </strong> J.
 N. Leichliter<em> et al.</em>, Nitrogen isotopes in tooth
 enamel record diet and trophic level enrichment: results from a controlled
 feeding experiment. <em>Chemical Geology</em>
 <strong>563</strong>, 120047 (2021). T.
 Lüdecke<em> et al.</em>, Carbon, nitrogen, and oxygen stable
 isotopes in modern tooth enamel: A case study from Gorongosa National
 Park, central Mozambique. <em>Frontiers in Ecology and
 Evolution</em> <strong>10</strong>,  (2022).
 S. Moretti<em> et al.</em>, Analytical improvements
 and assessment of long-term performance of the oxidation–denitrifier
 method. <em>Rapid Communications in Mass Spectrometry</em>
 <strong>38</strong>, e9650 (2024). T. F.
 Turner, M. L. Collyer, T. J. Krabbenhoft, A general hypothesis-testing
 framework for stable isotope ratios in ecological studies.
 <em>Ecology</em> <strong>91</strong>, 2227-2233
 (2010). H. Vonhof<em> et al.</em>,
 High‐precision stable isotope analysis of &lt;5 μg
 CaCO<sub>3</sub> samples by continuous‐flow mass spectrometry.
 <em>Rapid Communications in Mass Spectrometry</em>
 <strong>34</strong>, e8878 (2020).
description: # This dataset includes tables and files supporting the manuscript
 “***Australopithecus*** at Sterkfontein did not consume substantial
 mammalian meat” Contact Tina Lüdecke
 ([tina.luedecke@mpic.de](mailto:Tina.luedecke@mpic.de)) or Alfredo
 Martínez-García
 ([a.martinez-garcia@mpic.de)](mailto:Tina.luedecke@mpic.de) with any
 questions. This manuscript has been accepted at *Science* for publication
 (28-Nov-2024): Lüdecke, T., Leichliter, J.N., Stratford, D., Sigman, D.M.,
 Vonhof, H., Haug, G.H., Bamford, M.K., Martínez-García,
 A.: *Australopithecus *at Sterkfontein did not consume substantial
 mammalian resources. ##### The contents of these Datasets are described
 below 
 [https://doi.org/10.5061/dryad.vt4b8gv1f](https://doi.org/10.5061/dryad.vt4b8gv1f) **Tables S1 to S6, including:** Table S1: Summary of stable carbon and nitrogen isotope data for Sterkfontein Member 4 specimens (n = 43). Includes collection ID, taxon, group, stable carbon and nitrogen isotope values (‰) with standard deviation and number of replicates, enamel nitrogen content (nmol/mg) with standard deviation and number of replicates, sampled tooth specimen, excavation details (square and depth), cataloging, and identification information. Note: “n/a” (not applicable) is given for standard deviations of samples without replicas.   Table S2: Summary of stable carbon and nitrogen isotope data for modern tooth enamel (n = 67), compiled from Lüdecke and Leichliter et al. (2022) and Leichliter and Lüdecke et al. (2023). Includes collection ID, publication details, taxon, group, locality, stable carbon and nitrogen isotope values (‰) with standard deviation and number of replicates, enamel nitrogen content (nmol/mg) with standard deviation and number of replicates, and sampled tooth specimen. Note: “n/a” (not applicable) is given for standard deviations of samples without replicas.   Table S3: Summary of stable nitrogen isotope data for Makapansgat Limeworks specimens (n = 17), used in Figure S4. Includes collection ID, taxon, group, nitrogen isotope values (‰), and sampled tooth specimens. Table S4: Statistical results from nitrogen vs. carbon isotope niche analyses using the R package *SIBER*. Empty cells are retained for clarity in table formatting.  Table S5: Summary of blanks and standards (USGS and cleaning standards) used for nitrogen isotope measurements. Empty cells are retained for clarity.  Table S6: Summary of the in-house modern tooth enamel standard “AG-Lox” for stable carbon isotope measurements. Empty cells are retained for clarity.  **CSV Files 1 and 2, including:** CSV File 1: File with compiled stable carbon and isotope data of Sterkfontein fossils to be read by the provided R Script "SIBER" with δ13Cenamel values (iso1) and δ15Nenamel (iso2) values, taxonomic group classification, and community.  CSV File 2: File with compiled stable carbon and isotope data of modern African mammals to be read by the provided R Script "SIBER" with δ13Cenamel values (iso1) and δ15Nenamel (iso2) values, taxonomic group classification, and community.  **Code/Software, including:** R Script: Data was analyzed using the here provided R code modified after “Stable Isotopes Bayesian Ellipses (SIBER) package (version 2.1.6)”.