Australopithecus

Testing hypotheses of dietary reconstruction from buccal dental microwear in Australopithecus afarensis

by Jordi Galbany

F Estebaranz, L M Martínez, J Galbany, D Turbón, A Pérez-Pérez (2009) Testing hypotheses of dietary reconstruction from buccal dental microwear in Australopithecus afarensis. Journal of Human Evolution 57: 739-750.

A recent study of occlusal microwear in Australopithecus afarensis described this species as an opportunistic dweller,... more A recent study of occlusal microwear in Australopithecus afarensis described this species as an opportunistic dweller, living in both forested and open environments and greatly relying on fallback resources and using fewer food-processing activities than previously suggested. In the present study, analysis of buccal microwear variability in a sample of A. afarensis specimens (n = 75 teeth) showed no significant correlations with the ecological shift that took place around 3.5 Ma in Africa. These results are consistent with the occlusal microwear data available. In fact, significant correlations between buccal and occlusal microwear variables were found. However, comparison of the buccal microwear patterns showed clear similarities between A. afarensis and those hominoid species living in somewhat open environments, especially the Cameroon gorillas. A diet based mainly on succulent fruits and seasonal fallback resources would be consistent with the buccal microwear patterns observed.

Buccal dental microwear analyses support greater specialization in consumption of hard foodstuffs for Australopithecus anamensis

by Jordi Galbany

Ferran Estebaranz, Jordi Galbany, Laura M Martínez, Daniel Turbón & Alejandro Pérez-Pérez (2012, accepted) Buccal dental microwear analyses support greater specialization in consumption of hard foodstuffs for Australopithecus anamensis. Journal of Anthropological Sciences.

Molar occlusal microwear texture and anisotropy analyses of 3 Australopithecus anamensis fossil specimens have shown... more Molar occlusal microwear texture and anisotropy analyses of 3 Australopithecus anamensis fossil specimens have shown complexity values similar to those of Au.afarensis,indicating that neither of these hominin species had a diet dominated by hard food. However, many researchers have suggested that these were some of the earliest hominins to have such diets. Here we examine buccal microwear patterns of 5 Au. anamensis, 26 Au. afarensis, 48 Hominoidea and 80 Cercopithecoidea primate specimens for independent evidence of dietary adaptations of Au. anamensis. The buccal microwear results obtained suggest that the diet of Au.anamensis relied heavily on hard, brittle food, at least seasonally. This is similar to the diet of the extant Cercopithecoidea primates, including Papio anubis and Chlorocebus aethiops, both of which live in wooded, seasonal savannah environments and have diets that include fruit and grasses, but also underground storage organs (USOs), such as corms or blades, as well as leaves and seeds, and also Mandrillus and Cercocebus, from forested environments with frugivorous-granivorous diets. Furthermore, the buccal microwear patterns of Au.anamensis and Au.afarensis clearly differed –in clear contrast to occlusal enamel texture observations–, which support previous dietary interpretations based on both anatomical and palaeocological reconstructions.

Keywords: hominin, diet, feeding ecology, buccal microwear, fallback food, Australopithecus anamensis

The feeding biomechanics and dietary ecology of Australopithecus africanus

by Callum Ross

Strait, D.S., Weber, G.W., Neubauer, S., Chalk, J., Richmond, B.G., Lucas, P.W., Spencer, M.A., Schrein, C., Dechow, P.C., Ross, C.F., Grosse, I., Wright, B.W., Constantino, P., Wood, B.A., Lawn, B., Hylander, W.L., Wang, Q., Byron, C., Slice, D.E., Smith, A.L. (2009). The feeding biomechanics and dietary ecology of Australopithecus africanus. Proceedings of the National Academy of Sciences 106(7): 2124-2129.

The structural rigidity of the cranium of Australopithecus africanus: implications for diet, dietary adaptations, and the allometry of feeding biomechanics

by Callum Ross

Strait, D.S., Grosse, I., Dechow, P.C., Smith, A.L., Wang, Q., Weber, G.W., Neubauer, S., Slice, D.E., Chalk, J., Richmond, B.G., Lucas, P.W., Spencer, M.A., Schrein, C., Wright, B.W., Byron, C., Ross, C.F. (2010) The structural rigidity of the cranium of Australopithecus africanus: implications for diet, dietary adaptations and the allometry of feeding biomechanics. Anatomical Record 293: 582-593.

Roots, Bugs and Venison: Prehistoric Cuisine at Swartkrans Cave

by Jason Heaton

Co-Authored with Travis Pickering, 2009, in Quest: Science for South Africa

The context of Stw 573, an early hominid skull and skeleton from Sterkfontein Member 2: taphonomy and paleoenvironment

by Jason Heaton

Co-authored with Travis Pickering and Ron Clarke, 2004, in the Journal of Human Evolution

The reconstructed taphonomic and paleoenvironmental contexts of a ca. 4 million-year-old partial hominid skeleton (Stw... more The reconstructed taphonomic and paleoenvironmental contexts of a ca. 4 million-year-old partial hominid skeleton (Stw 573) from Sterkfontein Member 2 are described through presentation of the results of our analyses of the mammalian faunal assemblage associated stratigraphically with the hominid. The assemblage is dominated by cercopithecoids (Parapapio and Papio) and felids (Panthera pardus, P. leo, Felis caracal, and Felidae indet.), based on number of identified specimens, minimum number of elements and, minimum number of individuals. In addition, the assemblage is characterized by a number of partial skeletons and/or antimeric sets of bones across all taxonomic groups. There is scant indication of carnivore chewing in the assemblage. These observations, in addition to other taphonomic data, suggest that the remains of many animals recovered in Member 2 are from individuals that entered the cave on their own—whether accidentally by falling through avens connecting the cave to the ground surface above or by intentional entry—and were then unable to escape, rather than primarily through systematic collection by a biotic, bone-accumulating agent. The taphonomic conclusion that animals with climbing proclivities (i.e., primates and carnivores) are preferentially preserved over other taxa, ultimately because of those proclivities, urges caution in assessing the fidelity of the assemblage for reconstruction of the Member 2 paleoenvironment. With that caveat, we infer that the Member 2 paleoenvironment was typified by rolling, rock-littered and brush- and scrub-covered hills, indicated by the abundant F. caracal and cercopithecoid fossils recovered and the identified presence of the extinct Caprinae Makapania broomi. In addition, the valley bottom may have retained standing water year-round, perhaps supporting some tree cover—a setting suitable for the well-represented ambush predator P. pardus and suggested by the presence of Alcelaphini. Finally, the reconstructed taphonomic and paleoenvironmental settings of Sterkfontein Member 2 are compared to penecontemporaneous sites in South and East Africa.

Arboreal and terrestrial traits as revealed by the primate ankle joint

by Alexandra van der Geer

Paleoanthropology: our understanding of human evolutionary history

by Pierre-François Puech

co-authors: Pierre-Francois PUECH and Bernard PUECH

Who were the earliest humans?” After the chimp-hominid split (dated ~6 million years ago), the biped lineage leading... more Who were the earliest humans?” After the chimp-hominid split (dated ~6 million years ago), the biped lineage leading to us is characterized by tool making and by brain expansion. The earliest tools may date back to Australopithecus afarensis having anatomical characters conforming very closely for a early stage of human evolution. The earliest Homo is a fossil upper jaw from Hadar (Ethiopia). Dated to 2.3 myr ago, the palate and dental anatomy, similar to H. habilis (~2.0 to 1.5 myr ago), is intermediate between earlier australopiths and later Homo.

O’Regan, H. J. and Reynolds, S. C. (2009). An ecological reassessment of the southern African carnivore guild: a case study from Member 4, Sterkfontein, South Africa Journal of Human Evolution, Volume 572:212-222.

by Sally Reynolds

The southern African late Pliocene to early Pleistocene carnivore guild was much larger than that of the present day.... more The southern African late Pliocene to early Pleistocene carnivore guild was much larger than that of the present day. Understanding how this guild may have functioned is important for the reconstruction of carnivore-hominin interactions and to assess the potential for hominin scavenging in southern Africa. In modern ecosystems, the coexistence of larger carnivore species is constrained by several factors, which include high levels of interspecific competition. Here, the composition of the fossil carnivore guild is examined using Sterkfontein Member 4 (Cradle of Humankind, South Africa) as a case study. Sterkfontein
Member 4 contains 10 larger carnivore taxa (body mass > 21.5 kg) and may also contain two Australopithecus species. Two possible causes of higher numbers of carnivore species in the South African fossil record are initially considered. First, that there is a bias introduced through comparing assemblages of
differing sizes; second, carnivore biodiversity may have been artificially inflated due to previous taxonomic splitting of carnivore species, such as Crocuta. These possibilities are rejected and modern ecological data are used to construct a simple spatial model to determine how many carnivores could have co-existed. Although the resulting model indicates that the carnivore taxa present in Member 4 could have co-occurred, modern ecological studies indicate that it is highly unlikely that they would have co-existed simultaneously. Considering the complex depositional processes that operate in the southern African cave sites, it is proposed that the larger carnivore guild observed in the Sterkfontein Member 4 fossil assemblage is a palimpsest created by time-averaging. In light of this, we suggest that sites which
have a large number of carnivore taxa should be examined for time-averaging, while those sites which have relatively few species may be a better reflection of carnivore communities.