Anatomical variation of the Dorsalis pedis artery in a South African population- A Cadaveric Study

Abstract: The dorsalis pedis artery is responsible for blood supply to the dorsal aspect of the foot and is vital in the clinical assessment of the arterial supply thereof. Clinical assessment should consider anatomical variations of dorsalis pedis artery. Clearly, a thorough understanding of the potential variations of the vasculature in the area is important for a precise clinical assessment of arterial supply to the foot. The aim of this study was to investigate the different branching patterns of the dorsalis pedis artery that exist in a South African population. Methods: A Cadaveric study in which a total of 33 dissected lower limbs (27 adult cadavers and 6 partial wet lower limb specimens) of a South African population sample were studied. The course and branching pattern of the dorsalis pedis artery were photographed and documented. Results: Nine variations of the dorsalis pedis artery were recorded, with the standard branching pattern being the most common with an incidence of 36.36% and a completely absent dorsalis pedis artery variation was noted in 6.06% of the sample. Conclusion: Nine variations of the arterial anatomy of the dorsalis pedis artery were identified in this current study. Each of these may possibly alter the location or strength of the dorsalis pedis pulse affecting clinical assessment outcomes. Knowledge of dorsalis pedis variations may be useful to clinicians when making clinical decisions

New fossils of Australopithecus sediba reveal a nearly complete lower back

Abstract: Adaptations of the lower back to bipedalism are frequently discussed but infrequently demonstrated in early fossil hominins. Newly discovered lumbar vertebrae contribute to a near-complete lower back of Malapa Hominin 2 (MH2), offering additional insights into posture and locomotion in Australopithecus sediba. We show that MH2 demonstrates a lower back consistent with human-like lumbar lordosis and other adaptations to bipedalism, including an increase in the width of intervertebral articular facets from the upper to lower lumbar column (“pyramidal configuration”). This contrasts with recent work on lordosis in fossil hominins, where MH2 was argued to demonstrate no appreciable lordosis (“hypolordosis”) similar to Neandertals. Our three-dimensional geometric morphometric (3D GM) analyses show that MH2’s nearly complete middle lumbar vertebra is human-like in shape but bears large, cranially-directed transverse processes, implying powerful trunk musculature. We interpret this combination of features to indicate that A. sediba used its lower back in both human-like bipedalism and ape-like arboreal positional behaviors, as previously suggested based on multiple lines of evidence from other parts of the skeleton and reconstructed paleobiology of A. sediba

The morphology of the upper thorax of Australopithecus Sediba within the context of selected hominoids

The thoracic skeletal morphology of homininae is poorly known and understood. As a result of the representative fossil record of ribs and vertebrae being rare, distorted, fragmentary or unrecognised even when recovered, very little is known about the variability of rib and vertebral morphology when compared to the other cranial and postcranial elements in this lineage. Yet the costal skeleton forms a substantial part of the postcranial skeleton and thus ribs and vertebrae are therefore potentially numerous in the fossil record; but in comparison with other skeletal elements, and for the reasons mentioned above, very little is known about vertebrate and especially hominin rib morphology. The assessment of the structure of the thoracic skeletal elements and its evolutionary and ecological significance, particularly in the Homininae, poses a challenge but is still important as the shape and form of the rib cage has numerous functional and behavioural implications. The present study analysed the ribs of selected primate and non-primate mammalian species by examining fifteen variables, seven indices and eight osteological non-metric features. These observations and measurements were compared to ribs found in the fossil record in order to determine if there are any structural correlates between the extant and the extinct hominin and mammalian species and in order to create a template for the identification of hominin ribs within an abundant and diverse mammalian assemblage. The results suggest that the 1st rib, due to its unique morphology, may be considered most diagnostic in differentiating various taxa. In addition, a template for the morphology of the proximal end of the first rib has been created to be used for both the general as well as the specific identification of fossilised fragments, and to determine thoracic shape. The recently recovered costal elements of the Australopithecus sediba fossils were also examined as one of the most abundant assemblages of the elements in the early hominin record in order to add to our understanding of the morphology, and evolution of this poorly known area of hominin anatomy. The thorax of Australopithecus sediba demonstrates a medio-laterally narrow, ape-like upper thoracic shape, which is different from the broad upper thorax of Homo that has been associated with to the locomotor pattern of endurance walking and running. The lower thorax, however, is less laterally-flared than that of apes, and more closely approximates the morphology found in humans. This indicates a mosaic morphology of the thorax during the human evolutionary linage

Prevalence of sacral spina bifida occulta with lumbosacral transitional vertebra in a skeletal collection of a South African population

In this study, complete Sacral Spina Bifida Occulta (SSBO) and Lumbosacral Transitional Vertebrae (LSTV) with their various subtypes based on the Castellvi classification were appraised in a South African population sample. Adult human skeletons representing the three largest South African population groups, namely South African African, South African of Mixed Ancestry; South African of European descent; both biological sexes; and age range between 21 and 90 years at death were evaluated for both spinal anomalies.The number of preselected skeletons (n = 1798) from the largest collection in Africa of modern human skeletons (N = 2630) provided a strong representative South African sample. The observational study looked at lumbar and sacral vertebrae in each skeleton and any anomalous features were captured in an Excel spreadsheet.Complete SSBO with no LSTV was observed in eight subjects (8/1798; 0.44 %), while incomplete SSBO was observed in one subject (1/1798; 0.06 %), and one individual (1/1798; 0.06 %) exhibiting complete SSBO with LSTV (Type IIIB, Castellvi classification). No significant differences were observed when comparing the prevalence of the LSTV with SSBO in the male and female groups of the different population affinity groups. The number of individuals with SSBO was found in more South African Africans than in the other population groups with no significant difference between groups.This research revealed the simultaneous presence of two morphological anomalies (SSBO and LSTV) at the same vertebral segment that could result in low back pain. Variant morphology awareness is crucial for clinicians across all modalities to prevent misdiagnosis, leading to better treatment plans, and avoiding injury

Eco‐geographic adaptations in the human ribcage throughout a 3D geometric morphometric approach

Objectives: According to eco-geographic rules, humans from high latitude areas present larger and wider trunks than their low-latitude areas counterparts. This issue has been traditionally addressed on the pelvis but information on the thorax is largely lacking. We test whether ribcages are larger in individuals inhabiting high latitudes than in those from low latitudes and explored the correlation of rib size with latitude. We also test whether a common morphological pattern is exhibited in the thorax of different cold-adapted populations, contributing to their hypothetical widening of the trunk.Materials and methods: We used 3D geometric morphometrics to quantify rib morphology of three hypothetically cold-adapted populations, viz. Greenland (11 individuals), Alaskan Inuit (8 individuals) and people from Tierra del Fuego (8 individuals), in a comparative framework with European (Spain, Portugal and Austria; 24 individuals) and African populations (South African and sub-Saharan African; 20 individuals).Results: Populations inhabiting high latitudes present longer ribs than individuals inhabiting areas closer to the equator, but a correlation (p < 0.05) between costal size and latitude is only found in ribs 7-11. Regarding shape, the only cold adapted population that was different from the non-cold-adapted populations were the Greenland Inuit, who presented ribs with less curvature and torsion.Conclusions: Size results from the lower ribcage are consistent with the hypothesis of larger trunks in cold-adapted populations. The fact that only Greenland Inuit present a differential morphological pattern, linked to a widening of their ribcage, could be caused by differences in latitude. However, other factors such as genetic drift or specific cultural adaptations cannot be excluded and should be tested in future studies.Fil: García Martínez, Daniel. Museo Nacional de Ciencias Naturales; EspañaFil: Nalla, Shahed. University of Johannesburg; Sudáfrica. University of the Witwatersrand; SudáfricaFil: Ferreira, Maria Teresa. Universidad de Coimbra; PortugalFil: Guichon, Ricardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Sociales. Departamento de Arqueología. Laboratorio de Ecología Evolutiva Humana (Sede Quequén); ArgentinaFil: D'Angelo del Campo, Manuel D.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Sociales. Departamento de Arqueología. Laboratorio de Ecología Evolutiva Humana (Sede Quequén); Argentina. Universidad Autónoma de Madrid; EspañaFil: Bastir, Markus. Museo Nacional de Ciencias Naturales; Españ

3D geometric morphometrics of the cold-adapted thorax: eco-geographical variability of the human rib cage

Presentación de una comunicación dada en: II Iberian Symposium on geometric morphometrics, celebrado los dias 9 y 10 de junio de 2016 en MadridDespite the importance of the thorax for human biology, its 3D morphological variability associated to eco-geographical variation is poorly understood. Allen´s and bergmann´s eco-geographic rules link body size and shape to climate conditions in homoeothermic mammals.Peer reviewe

The Decreasing Prevalence of the Arcuate Foramen

[Background]: The arcuate foramen (AF), or ponticulus posticus, is an anatomic variant of the first cervical vertebra that consists of a complete or partial osseous bridge over the groove for the vertebral artery and extends from the posterior aspect of the superior articular facet to the superior lateral border of the posterior arch. The AF has been associated with clinical symptoms, such as headache, migraine, neck pain, shoulder pain, arm pain, and vertebral artery dissection. We aimed to test whether the prevalence of the AF has decreased in the modern human population over the past centuries as a result of reduction in inbreeding and endogamy.[Methods]: Possible reduction in the prevalence of the AF was assessed by comparing a 17th century rural sample (n = 108) with a 20th century modern urban sample (n = 192).[Results]: When comparing the 17th and the 20th century samples, we found a statistically significant (P = 0.003) reduction of 14.5% (95% confidence interval 4.5–24.5) in the prevalence of the AF

The vertebrae and ribs of Homo naledi

Hominin evolution featured shifts from a trunk shape suitable for climbing and housing a large gut to a trunk adapted to bipedalism and higher quality diets. Our knowledge regarding the tempo, mode, and context in which these derived traits evolved has been limited, based largely on a small-bodied Australopithecus partial skeleton (A.L. 288-1; “Lucy”) and a juvenile Homo erectus skeleton (KNM-WT 15000; “Turkana Boy”). Two recent discoveries, of a large-bodied Australopithecus afarensis (KSD-VP-1/1) and two Australopithecus sediba partial skeletons (MH1 and MH2), have added to our understanding of thorax evolution; however, little is known about thorax morphology in early Homo. Here we describe hominin vertebrae, ribs, and sternal remains from the Dinaledi chamber of the Rising Star cave system attributed to Homo naledi. Although the remains are highly fragmented, the best-preserved specimens—two lower thoracic vertebrae and a lower rib—were found in association and belong to a small-bodied individual. A second lower rib may belong to this individual as well. All four of these individual elements are amongst the smallest known in the hominin fossil record. H. naledi is characterized by robust, relatively uncurved lower ribs and a relatively large spinal canal. We expect that the recovery of additional material from Rising Star Cave will clarify the nature of these traits and shed light on H. naledi functional morphology and phylogeny.DGM and MB were funded through CGL2012-37279, MINECO, SpainPeer Reviewe