Papers by Bernhard Zipfel
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The Foot
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Science Advances
The frontal sinuses are cavities inside the frontal bone located at the junction between the face... more The frontal sinuses are cavities inside the frontal bone located at the junction between the face and the cranial vault and close to the brain. Despite a long history of study, understanding of their origin and variation through evolution is limited. This work compares most hominin species’ holotypes and other key individuals with extant hominids. It provides a unique and valuable perspective of the variation in sinuses position, shape, and dimensions based on a simple and reproducible methodology. We also observed a covariation between the size and shape of the sinuses and the underlying frontal lobes in hominin species from at least the appearance of Homo erectus . Our results additionally undermine hypotheses stating that hominin frontal sinuses were directly affected by biomechanical constraints resulting from either chewing or adaptation to climate. Last, we demonstrate their substantial potential for discussions of the evolutionary relationships between hominin species.
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HOMO, 2006
Two hominin metatarsals from Swartkrans, SKX 5017 and SK 1813, have been reported by Susman and B... more Two hominin metatarsals from Swartkrans, SKX 5017 and SK 1813, have been reported by Susman and Brain [1988. New first metatarsal (SKX 5017) from Swartkrans and the gait of Paranthropus robustus. Am. J. Phys. Anthropol. 79, 451-454] and Susman and de Ruiter [2004. New hominin first metatarsal (SK 1813) from Swartkrans. J. Hum. Evol. 47, 171-181]. They found these bones to have both primitive and derived traits indicating that, while being bipedal, these hominines had a unique toe-off mechanism. We have undertaken additional multivariate morphometric analyses, comparing the fossils to the first metatarsals of modern humans and extant apes. The largest proportion of discrimination lies in the different locomotor functions: apes on the one hand and the humans and fossils on the other. While the fossils have the closest affinity to humans, they have a unique biomechanical pattern suggesting a more facultative form of bipedalism. The implications of this are, while morphometric analyses do not necessarily directly capture the described primitive and derived traits, the associated functional pattern is held within the broader morphology of the bone.
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PLoS ONE, 2009
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Hominin Postcranial Remains from Sterkfontein, South Africa, 1936-1995
This chapter summarizes the findings presented in the preceding chapters. To our knowledge, this ... more This chapter summarizes the findings presented in the preceding chapters. To our knowledge, this volume represents the first source presenting all these fossils together in one collection. The chapters in this book provide photographs, measurements, and basic descriptions of each postcranial fossil. They present comparative observations and analyses and statistical analysis of taxonomically and functionally relevant aspects of morphology, and in some cases they provide reconstructions of the bones. Each of the chapters in this volume addresses key questions surrounding the Sterkfontein hominins. The Sterkfontein specimens share with other hominins features of the vertebral column, thorax, hip, knee, ankle, and foot indicating fully upright, human-like posture. Among many anatomical regions, though, the A. africanus fossils appear distinct from those attributed to A. afarensis, yet the variation between these samples often does not exceed that observed within single species of extant...
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Proceedings of the National Academy of Sciences
The origins of Homo , as well as the diversity and biogeographic distribution of early Homo speci... more The origins of Homo , as well as the diversity and biogeographic distribution of early Homo species, remain critical outstanding issues in paleoanthropology. Debates about the recognition of early Homo , first appearance dates, and taxonomic diversity within Homo are particularly important for determining the role that southern African taxa may have played in the origins of the genus. The correct identification of Homo remains also has implications for reconstructing phylogenetic relationships between species of Australopithecus and Paranthropus , and the links between early Homo species and Homo erectus . We use microcomputed tomography and landmark-free deformation-based three-dimensional geometric morphometrics to extract taxonomically informative data from the internal structure of postcanine teeth attributed to Early Pleistocene Homo in the southern African hominin-bearing sites of Sterkfontein, Swartkrans, Drimolen, and Kromdraai B. Our results indicate that, from our sample o...
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Quaternary Science Reviews, 2022
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L'Anthropologie
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Scientific Reports
Most fossil hominin species are sampled with spatial, temporal or anatomical biases that can hind... more Most fossil hominin species are sampled with spatial, temporal or anatomical biases that can hinder assessments of their paleodiversity, and may not yield genuine evolutionary signals. We use new fossils from the Kromdraai (Unit P) and Drimolen sites (South Africa) to provide insights into the paleodiversity of the Lower Pleistocene robust australopith, Paranthropus robustus. Our focus is the morphology of the temporal bone and the relationships between size and shape (allometry) of the semi-circular canals (SCC), an aspect that has not yet been investigated among southern African australopiths. We find significant size and shape SCC differences between P. robustus from Kromdraai, Drimolen and Swartkrans. This site-related variation is consistent with other differences observed on the temporal bone. P. robustus from Kromdraai Unit P is distinctive because of its smaller temporal bone and SCC, and its proportionally less developed posterior SCC, independently of age and sex. We empha...
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Hominin Postcranial Remains from Sterkfontein, South Africa, 1936-1995
The metatarsals and tarsals from most of the foot bones found at Sterkfontein by the time of this... more The metatarsals and tarsals from most of the foot bones found at Sterkfontein by the time of this monograph have been described previously, but this chapter presents new analyses and interpretations of these important specimens. The hominin forefoot, comprised of the metatarsus and phalanges, represents an important functional component of the foot that can potentially answer a number of questions regarding the evolution of the foot, more specifically the advent of bipedalism in the human lineage. Metatarsal morphology suggests that the lateral column of the Sterkfontein hominin feet was human-like, and similar to that of virtually all other known hominins, suggesting a stable lateral column early in the evolution of the foot. In contrast, the medial column shows a mosaic of derived and ape-like characters consistent with bipedalism, but also with grasping in arboreal behavior. There is arguably also evidence of two morphs in foot morphology and function, suggesting a second species...
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Journal of Human Evolution, 2022
Homo erectus s.l. is key for deciphering the origin and subsequent evolution of genus Homo. Howev... more Homo erectus s.l. is key for deciphering the origin and subsequent evolution of genus Homo. However, the characterization of this species is hindered by the existence of multiple variants in both mainland and insular Asia, as a result of divergent chronogeographical evolutionary trends, genetic isolation, and interbreeding with other human species. Previous research has shown that cochlear morphology embeds taxonomic and phylogenetic information that may help infer the phylogenetic relationships among hominin species. Here we describe the cochlear morphology of two Indonesian H. erectus individuals (Sangiran 2 and 4), and compare it with a sample of australopiths, Middle to Late Pleistocene humans, and extant humans by means of linear measurements and both principal components and canonical variates analyses performed on shape ratios. Our results indicate that H. erectus displays a mosaic morphology that combines plesiomorphic (australopithlike) features (such as a chimplike round cochlear cross section and low cochlear thickness), with derived characters of later humans (a voluminous and long cochlea, possibly related to hearing abilities)-consistent with the more basal position of H. erectus. Our results also denote substantial variation between the two studied individuals, particularly in the length and radius of the first turn, as well as cross-sectional shape. Given the small size of the available sample, it is not possible to discern whether such differences merely reflect intraspecific variation among roughly coeval H. erectus individuals or whether they might result from greater age differences between them than currently considered. However, our results demonstrate that most characters found in later humans were already present in Indonesian H. erectus, with the exception of Neanderthals, which display an autapomorphic condition relative to other Homo species.
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The Coronavirus disease 2019 (COVID-19) pandemic is clearly taking a firmer grip on South Africa ... more The Coronavirus disease 2019 (COVID-19) pandemic is clearly taking a firmer grip on South Africa and more podiatrists will face the potential transmission of SARS-CoV-2. Government response was swift with the implementation of a travel ban, strict national lockdown as well as social distancing and hygiene protocols in line with international health regulations. Co-morbidities such as tuberculosis and HIV/AIDS, endemic to South Africa, are considered a dangerous combination with COVID-19, making many South Africans vulnerable to contracting the COVID-19. Patients with diabetes as well as the aged are vulnerable, both in terms of potential combined complications and challenges in continuity in foot care. The demands of the pandemic may outstrip the ability of the health systems to cope. Should this time arrive, all healthcare practitioners, including podiatrists, would have to step in and take on a role beyond their scope of practice in order to ensure that the healthcare system does ...
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This study uses a new, empirical approach to calculate internal carotid artery (ICA) blood flow r... more This study uses a new, empirical approach to calculate internal carotid artery (ICA) blood flow rate from the radius of the carotid canal. So it is worthwhile to compare this “empirical equation” with the previous one based on the Poiseuille-derived “shear stress equation”. The techniques used to measure the canal size (CT scans, microphotographs and impression casting) are comparable, and a sensitivity analysis of the shear stress equation reveals reasonable accuracy (Qiaohui Hu et al. MS submitted). However, there are two assumptions that weaken the foramen technique and use of the shear stress equation: the arterial wall thickness-to-lumen radius ratio is assumed a constant (Assumption 1) and the scaling of wall shear stress is calculated from the body mass of the animal (Assumption 2).
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South African Journal of Science, 2021
Mechanical loading of finger bones (phalanges) can induce angular curvature, which benefits arbor... more Mechanical loading of finger bones (phalanges) can induce angular curvature, which benefits arboreal primates by dissipating forces and economising the recruitment of muscles during climbing. The recent discovery of extremely curved phalanges in a hominin, Homo naledi, is puzzling, for it suggests life in an arboreal milieu, or, alternatively, habitual climbing on vertical rock surfaces. The importance of climbing rock walls is attested by several populations of baboons, one of which uses a 7-m vertical surface to enter and exit Dronkvlei Cave, De Hoop Nature Reserve, South Africa. This rock surface is an attractive model for estimating the probability of extreme mechanical loading on the phalanges of rock-climbing primates. Here we use three-dimensional photogrammetry to show that 82–91% of the climbable surface would generate high forces on the flexor tendon pulley system and severely load the phalanges of baboons and H. naledi. If such proportions are representative of vertical r...
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Health SA Gesondheid, 2019
Background: Plantar fasciitis is one of the common causes of heel pain and a common musculoskelet... more Background: Plantar fasciitis is one of the common causes of heel pain and a common musculoskeletal problem often observed by clinicians. Numerous options are available in treating plantar fasciitis conservatively, but no previous studies have compared combined conservative management protocols.Aim: The aim of this study was to compare manipulation of the foot and ankle and cross friction massage of the plantar fascia; cross friction massage of the plantar fascia and gastrocsoleus complex stretching; and a combination of the aforementioned protocols in the treatment of plantar fasciitis.Setting: This study was conducted at the University of Johannesburg, Chiropractic Day Clinic, and included participants that complied with relevant inclusion criteria.Methods: Forty-five participants between the ages of 18 and 50 years with heel pain for more than 3 months were divided into three groups and received one of the proposed treatment interventions. The data collected were range of motion ...
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Journal of Human Evolution, 2019
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Papers by Bernhard Zipfel