Wits Evolutionary Studies Institute (ESI)

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    A hominin first rib discovered at the Sterkfontein Caves, South Africa.
    (Academy of Science of South Africa (ASSAf), 2016-05) Tawane, G.; Garcia-Martinez, D.; Eyre, J.; Bastir, M.; Berger, L.R.; Schmid, P.; Nalla, S.; Williams, S.A.
    First ribs - the first or most superior ribs in the thorax - are rare in the hominin fossil record, and when found, have the potential to provide information regarding the upper thorax shape of extinct hominins. Here, we describe a partial first rib from Member 4 of the Sterkfontein Caves, South Africa. The rib shaft is broken away, so only the head and neck are preserved. The rib is small, falling closest to small-bodied Australopithecus first ribs (AL 288-1 and MH1). Given that it was recovered near the StW 318 femur excavation, which also represents a small individual, we suggest that the two may be associated. Three-dimensional geometric morphometric analyses were used to quantify the rib fragment morphology and compare it to extant hominoid and other fossil hominin ribs. While only the proximal end is preserved, our analyses show that South African Australopithecus share derived features of the proximal first rib more closely resembling A. afarensis and later hominins than great apes.
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    Renewed investigations at Taung; 90 years after the discovery of Australopithecus africanus
    (2016-10-18) Kuhn, Brian F; Herries, Andy I R; Price, Gilbert J; Baker, Stephanie E; Hopley, Philip; Menter, Colin; Caruana, Matthew V
    2015 marked the 90th anniversary of the description of the first fossil ofAustralopithecus africanus, commonly known as the Taung Child, which was unearthed during blasting at the Buxton-Norlim Limeworks (referred to as the BNL) 15 km SE of the town of Taung, South Africa. Subsequently, this site has been recognized as a UNESCOWorld Heritage site on the basis of its importance to southern African palaeoanthropology. Some other sites such as Equus Cave and Black Earth Cave have also been investigated; but the latter not since the 1940s. These sites indicate that the complex of palaeontological and archaeological localities at the BNL preserve a time sequence spanning the Pliocene to the Holocene. The relationship of these various sites and how they fit into the sequence of formation of tufa, landscapes and caves at the limeworks have also not been investigated or discussed in detail since Peabody’s efforts in the 1940s. In this contribution we mark the 90th anniversary of the discovery and description of the Taung Child by providing a critical review of previous work at Taung based on our recent preliminary work at the site. This includes a reassessment of the Taung Child Type Site, as well as renewed excavations at Equus Cave and the lesser-known locality and little-investigated Black Earth Cave. Preliminary results suggest that much of our previous understandings of the BNL’s formational history and site formation processes need to be reassessed. Only through detailed analysis on the BNLas a whole can we understand this complex depositional environment.
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    Taxonomic status of the skull A.l.444-2 from the Pliocene of Hadar, Ethiopia
    (Bernard Price Institute for Palaeontological Research, 1999) Ferguson, Walter W
    A nearly complete hominid skull, A.L.444-2, from the Pliocene of Hadar in Ethiopia, has been attributed to Australopithecus afarensis Johanson, White & Coppens 1978. Comparative morphological analysis indicates that it may not conform to this species. Cranial and dental morphology and measurements of A.L.444-2 agree more closely with those of A. africanus Dart 1925, to which it could be reassigned.
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    Enamel thickness in South African australopithecines: noninvasive evaluation by computed tomography
    (BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1991) Conroy, Glenn C
    Until recently, it has not been possible to systematically study enamel thickness in fossil hominids except by physically sectioning the teeth. Because sectioning studies destroy original specimens, sample sizes will always be low. For this reason, anthropologists have had to devise other methods for acquiring these data such as by measuring enamel in naturally fractured teeth or where it is exposed in worn teeth. It is clearly important to develop and apply non-invasive techniques to augment and expand the data base of early hominid enamel thickness. This is a first attempt to provide such data for a sample of South African australopithecines by utilizing high-resolution computed tomography (CT). This study is based on over 130 CT scans taken at 1 mm slice thickness on a sample of 22 original Australopithecus africanus and A. robustus lower molars from Sterkfontein, Kromdraai, Makapansgat, Swartkrans and Taung. Mean values of absolute and relative enamel thickness between A. africanus and A. robustus are significantly different, confirming that robust australopithecines have thicker enamel than their gracile counterparts. CT sections were taken in the buccolingual plane through the mesial cusps (protoconid, metaconid). While the mean value of enamel thickness at the buccal cusp (protoconid) is greater in A. robustus than in A. africanus, the difference is not statistically significant. The difference in enamel thickness at the lingual cusp (metaconid) is statistically significant, however. This study represents an important, albeit preliminary, first step in establishing a methodology for the non-invasive evaluation of enamel thickness in fossil hominids by computed tomography. It demonstrates the viability of the technique and the type of problem oriented approach that can be tackled using computed tomography in modem anthropological research. Measurements derived from CT cannot, of course, be expected to have the same degree of precision as those taken directly from sectioned teeth; nevertheless, important insights into the functional morphology of early hominid teeth are still easily decipherable from the CT data. Given that the alternative to CT is the physical destruction of original hominid fossils, the slight loss in mensurational accuracy seems well worth the price.
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    Partial hominin tibia (StW 396) from Sterkfontein, South Africa
    (Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, 2009-12) Zipfel, Bernhard; Berger, Lee R.
    Comparison of a proximal hominin tibial fragment, StW 396 from Sterkfontein Member 4, South Africa, with the StW 514a tibia, also from Member 4 and attributed to Australopithecus africanus, indicates a degree of morphological variability that may represent the extremes of intraspecific variability or even exceed what one would expect from intraspecific variation alone. The morphology of StW 396 is human-like which suggests adaptations towards stability at the knee, whilst that of StW 514a is interpreted as being more mobile and ape-like (Berger & Tobias 1996). Four features separate the two morphological patterns. In StW 514a the attachment area of m. semimembranosus is strongly localized, whereas in StW 396 the posteromedial border is notched near the base of the lateral intercondylar tubercle; thirdly, the lateral tibial condyle of StW 514a is supero-inferiorly thin, whereas in StW 396 the lateral condyle is supero-inferiorly thickened and the contrast between the condyle and the shaft is less pronounced; lastly the articular surface of the medial condyle of StW 396 is anteroposteriorly broad and highly concave as opposed to the narrower, flatter surface of StW 514a. The degree of variability of the two specimens possibly suggests differing functional adaptations and may thus support an hypothesis suggesting that two hominin species may be represented within Sterkfontein Member 4.