Shahed Nalla - Profile on Academia.edu (original) (raw)
Papers by Shahed Nalla
Arcuate foramen prevalence in South African subjects: A cadaveric study based on 120 atlas vertebrae
Translational Research in Anatomy
Diagnostics
Cervical vertebrae may exhibit the anomalous presence of a double transverse foramen (DTF) that m... more Cervical vertebrae may exhibit the anomalous presence of a double transverse foramen (DTF) that may impact the anatomy of related structures that traverse the cervical region, such as the vertebral artery (VA). This retrospective anatomical study utilized CT angiography cervical scans to examine the prevalence of DTF, VA, and TF areas. The subjects were separated into two groups: normal TF (NTF group; 26 males and 21 females) and double TF (DTF group; 21 males and 24 females). The males presented significantly higher TF area values (30.31 ± 4.52 mm2) than the females (27.48 ± 1.69 mm2) in the NTF group (p = 0.006). The sex differences disappeared when a DTF was present (p = 0.662). There were no differences in the VA area values between the sexes in both the NTF and DTF groups (p = 0.184). No significant differences in the VA area values between males of the NTF and DTF groups (p = 0.485) were noted. The DTF subjects presented an increased VA/TF area ratio than the NTF subjects (p &...
Effect of APOE4 Allele and Gender on the Rate of Atrophy in the Hippocampus, Entorhinal Cortex, and Fusiform Gyrus in Alzheimer’s Disease
Current Alzheimer Research
Background: The hippocampus, entorhinal cortex, and fusiform gyrus are brain areas that deteriora... more Background: The hippocampus, entorhinal cortex, and fusiform gyrus are brain areas that deteriorate during early-stage Alzheimer’s disease (AD). The ApoE4 allele has been identified as a risk factor for AD development, is linked to an increase in the aggregation of amyloid ß (Aß) plaques in the brain, and is responsible for atrophy of the hippocampal area. However, to our knowledge, the rate of deterioration over time in individuals with AD, with or without the ApoE4 allele, has not been investigated. Method: In this study, we, for the first time, analyze atrophy in these brain structures in AD patients with and without the ApoE4 using the Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset. Results: It was found that the rate of decrease in the volume of these brain areas over 12 months was related to the presence of ApoE4. Further, we found that neural atrophy was not different for female and male patients, unlike prior studies, suggesting that the presence of ApoE4 is not ...
Homo naledi lumbar vertebrae and a new 3D method to quantify vertebral wedging
American Journal of Biological Anthropology
ObjectivesIn humans and known fossil hominins, lumbar lordosis is produced by vertebral body wedg... more ObjectivesIn humans and known fossil hominins, lumbar lordosis is produced by vertebral body wedging and other bony and soft tissue features such as the shape of the intervertebral discs. Current techniques for quantifying the wedging of vertebral bodies are limited in utility, especially when analyzing incomplete fossil material. Here, we introduce a 3D method to quantify vertebral body wedging angles that yields the angles between two “best fit” planes in the software GeoMagic Wrap (3D Systems).Materials and MethodsTo test that this new method is repeatable with existing methods, we measure the wedging of 320 lumbar vertebrae representing 64 modern human individuals. For each vertebra, wedging angles were calculated from linear measurements taken with calipers and compared with estimates generated from the 3D best fit plane method. We also apply the 3D plane method to fossil hominin lumbar vertebrae, including newly described lumbar vertebrae of Homo naledi, the majority of which ...
The Vertebrae, Ribs, and Sternum of Australopithecus sediba: Special Issue: Australopithecus sediba
Paleoanthropology, Dec 31, 2018
Australopithecus sediba is known from two partial skeletons, Malapa Hominins 1 and 2 (MH1 and MH2... more Australopithecus sediba is known from two partial skeletons, Malapa Hominins 1 and 2 (MH1 and MH2), a juvenile male and an adult female, respectively. Forty-eight elements of the axial skeleton, including vertebrae, ribs, a sternum, and a sacrum, are known from MH1 and MH2. Here, we describe these ~2.0 Ma fossils and provide raw data and plots of standardized measurements. We revisit the serial positions of the previously described vertebrae and ribs proposed in their initial announcements and provide revised identifications. Additionally, we include in our descriptions and analyses new axial material. Finally, we also test the hypothesis that multiple species are represented in the MH1 and MH2 material and specifically that MH1’s lumbar vertebrae belong to a member of the genus Homo, whereas those of MH2 belong to Australopithecus. We do not find support for this hypothesis, and instead attribute differences between MH1 and MH2 to their age difference and incomplete growth of the vertebral body in juvenile MH1.
Quaternary International, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
A pilot study on the uncovertebral joints and their degenerative changes in the aetiology of cervical spondylosis
The Foot, 2018
Background: The dorsalis pedis artery is responsible for blood supply to the dorsal aspect of the... more Background: 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.
African Vision and Eye Health
Background: Corneal changes occur as a direct consequence of diabetes mellitus (DM). The central ... more Background: Corneal changes occur as a direct consequence of diabetes mellitus (DM). The central corneal thickness (CCT) is a useful parameter that provides information about the status of the metabolism of the cornea and can therefore help monitor the progression of DM.Aim: The aim of this study was to determine the impact of DM on CCT and its correlation with diabetes duration and glycated haemoglobin (HbA1c) levels.Methods: The systematic review was undertaken to answer: (1) What effect does DM have on CCT values? (2) What effect does DM duration have on CCT values? (3) What effect does HbA1c levels have on CCT values? The Web of Science was used to conduct a computerised search for articles of CCT values in DM.Results: A total of 38 articles that met the criteria for inclusion were included in this systemic review. The researchers found 27 articles that observed increased CCT values in DM patients compared with control subjects. There were six studies in which increased CCT valu...
Differences in gonial angle values between Chalcolithic and present subjects
Hallux Valgus and 1st Metatarsal head Morphology - a South African Study
Thoracolumbar vertebrae and ribs
Hominin Postcranial Remains from Sterkfontein, South Africa, 1936-1995, 2020
This chapter describes and presents analysis of all vertebrae and ribs for the Sterkfontein homin... more This chapter describes and presents analysis of all vertebrae and ribs for the Sterkfontein hominins, including those associated with the Sts 14 and 431 skeletons. New rib fragments recently identified and accessioned with Sts 14 are included. Taken together, the vertebrae and ribs of the Sterkfontein hominins tell a consistent story. With one exception from Member 5 that may be attributable to Homo, all other specimens are consistent with being attributed to the same species, likely Australopithecus africanus. Overall, all the Sterkfontein specimens resemble those from other early hominins, reflecting a fundamentally human-like torso, with a series of sinusoidal spinal curvatures similar to those of hominins. These characteristics are distinctly human-like, are dissimilar from any other mammal, and are consistent with a fully upright posture. Sts 14 also displays two common spinal pathologies seen in humans but not in other hominoids, associated with the sinusoidal spinal curvature...
South African Journal of Science, 2016
First ribs - the first or most superior ribs in the thorax - are rare in the hominin fossil recor... more 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 grea...
eLife, 2015
Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Cha... more Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.
Supplementary Materials for
A New Species of Canid from the Malapa Hominin Site, Gauteng, South Africa
ABSTRACT The recently discovered hominin bearing site of Malapa (Gauteng South Africa), type loca... more ABSTRACT The recently discovered hominin bearing site of Malapa (Gauteng South Africa), type locality for Australopithecus sediba, has yielded a mammalian fossil assemblage that is remarkable in both its taxonomic breadth and preservational quality. Many of the species that have been identified from this assemblage are represented by multiple elements from single individuals – a rarity for the South African fossil record. Numerous specimens of carnivorans have also been described from the site including both large and small species. Here we examine a smaller sample of specimens that represent the second new species (after A. sediba) to emerge from the 1.977 million year old Malapa sample – a new small canid that we attribute to the genus Vulpes. The type specimen, University of the Witwatersrand (UW) 88-812 is a right mandibular fragment that includes part of the alveolus of the p3, the complete p4 and m1, the alveoli of m2 and m3 and the entire distal portion of the mandible. The coronoid, condylar and angular processes as well as mandibular foramen and masticatory muscle insertion scars are well preserved. Another specimen (UW 88-814) is a complete right m2 crown that we believe is from the same individual. Likewise, a complete right rib (UW 88-813) from a small canid was also recovered from the same breccia block. Given the preservational state of Malapa (almost no taphonomic mixing of the sample), this specimen likely came from the same individual. Relative to a large sample of individuals of modern and fossil Vulpes as well as other small canid genera (which can be excluded based on morphology), the new Malapa species of Vulpes is defined by the lack of distal accessory cusp on its p4, mesiodistally compressed and high-crowned m1 trigonid, relatively large m2, and relatively small condyle. Overall, this new species is gracile with high-crowned sharp teeth, suggesting, despite its lack of accessory cusps, a tendency toward hypercarnivory or insectivory.
A new species of fox from theAustralopithecus sedibatype locality, Malapa, South Africa
Transactions of the Royal Society of South Africa, 2013
ABSTRACT The 1.977 Ma site of ‘Malapa’ (Gauteng, South Africa) has yielded important new fossils,... more ABSTRACT The 1.977 Ma site of ‘Malapa’ (Gauteng, South Africa) has yielded important new fossils, including the type specimens of the new hominin species Australopithecus sediba. Recently, we reported the first Carnivora specimens to have been recovered from the site. That sample included members of Felidae, Herpestidae and Hyaenidae. That first report also included three associated small canid specimens (an M2, a rib and a posterior mandibular fragment including the P4, M1, coronoid, condylar and angular processes) that we attributed to Vulpes cf. V. chama. In this paper, we compare these specimens to a broad sample of modern and fossil foxes and conclude that these specimens are distinct enough to be referred to a new species, here described and named Vulpes skinneri.
Science, 2013
of early hominin fossils on the continent of Africa. The fossil remains of Au. sediba were discov... more of early hominin fossils on the continent of Africa. The fossil remains of Au. sediba were discovered in August of 2008, and the species was named in 2010 (1)* and given a provisional age of ~1.78 to 1.95 Ma (2). In 2011, detailed studies of four critical areas of anatomy of these remains were published (3-6), and a refi ned date of ~1.977 to 1.98 Ma was proposed (7). The six articles presented in full in the online edition of Science (www.sciencemag.org/site/extra/sediba), with abstracts in print (pp. 164-165), complete the initial examination of the prepared material attributed to three individuals: the holotype and paratype skeletons, commonly referred to as MH1 and MH2, and the adult isolated tibia referred to as MH4. They, along with the cumulative research published over the past 3 years, provide us with a comprehensive examination of the anatomy of a single species of early hominin. Irish et al. examine highly heritable nonmetric dental traits in Au. sediba. The species appears phylogenetically distinct from East African australopiths but close to Au. africanus, forming a southern African australopith clade. The latter shares some derived states with a clade comprising four fossil samples of the genus Homo. This result has implications for our present understanding of hominin phylogeny through the terminal Pliocene and suggests a possibility that Au. sediba, and perhaps Au. africanus, did not descend from the Au. afarensis lineage. De Ruiter et al. examine mandibular material attributable to MH2, including the previously unknown mandibular incisors and premolars of Au. sediba. As seen elsewhere in the cranium and skeleton, these mandibular remains share similarities with those of other australopiths but differ from Au. africanus in both size and shape, as well as in their ontogenetic growth trajectory. These results further support the claim that Au. sediba is taxonomically distinct from Au. africanus. Where the Au. sediba mandibles differ from those of Au. africanus, they appear most similar to those of representatives of early Homo. Churchill et al. explore the upper limb elements of Au. sediba, describing the most complete and undistorted humerus, radius, ulna, scapula, clavicle, and manubrium yet described from the early hominin record, all associated with one individual. With the exception of the hand skeleton (3), the upper limbs of the Malapa hominins are largely primitive in their morphology. Au. sediba thus shares with other australopiths an upper limb that was well suited for arboreal climbing and possibly suspension, although perhaps more so than has previously been suggested for this genus.
Science, 2013
The shape of the thorax of early hominins has been a point of contention for more than 30 years. ... more The shape of the thorax of early hominins has been a point of contention for more than 30 years. Owing to the generally fragmentary nature of fossil hominin ribs, few specimens have been recovered that have rib remains complete enough to allow accurate reassembly of thoracic shape, thus leaving open the question of when the cylindrical-shaped chest of humans and their immediate ancestors evolved. The ribs of Australopithecus sediba exhibit a mediolaterally narrow, ape-like upper thoracic shape, which is unlike the broad upper thorax of Homo that has been related to the locomotor pattern of endurance walking and running. The lower thorax, however, appears less laterally flared than that of apes and more closely approximates the morphology found in humans.
Geometric morphometrics of hominoid thoraces and its bearing for reconstructing the ribcage of H. naledi
H. naledi shows a mosaic morphological pattern with several derived (Homo-like) features of the s... more H. naledi shows a mosaic morphological pattern with several derived (Homo-like) features of the skull, hands and feet, and primitive (australopith- like) features in the ribcage, shoulder, and pelvis. This pattern reflects a morphology that might be expected of a hominin at the evolutionary transition between Australopithecus and Homo. Two thoracic vertebrae from levels 10 and 11 and the proximal aspect of an 11th rib were found in near anatomical connection in the Dinaledi Chamber of Rising Star cave, therefore likely belonging to the same individual. In this study we explore this association and report our ongoing work towards a quantitative 3D reconstruction of the H. naledi thorax. We measured 512 3D-(semi)landmarks on human and other hominoid ribcages (hylobatids, Pongo, Gorilla, Pan; N=33) for geometric morphometric analyses. Covariation between the 11th rib and remaining thorax shape was analyzed by partial least squares analysis (PLS) and overall thorax variation by principal components analysis (PCA). PCA results show wide ranges of complex thoracic variation. Gorilla and Pan are characterized by highly constricted upper thoraces when compared to their wide lower ribcages. Pongo and hylobatids have less narrow upper but also wide lower thoraces. Those of humans are expanded superiorly, narrow inferiorly, and with declined ribs. PLS analyses suggest that the morphology of the articulated rib-vertebra complex at the 11th level of H. naledi is compatible with a ribcage with declined ribs and inferiorly wider than observed in humans. This corresponds with evidence for laterally flared iliac blades of the H. naledi pelvis.
Arcuate foramen prevalence in South African subjects: A cadaveric study based on 120 atlas vertebrae
Translational Research in Anatomy
Diagnostics
Cervical vertebrae may exhibit the anomalous presence of a double transverse foramen (DTF) that m... more Cervical vertebrae may exhibit the anomalous presence of a double transverse foramen (DTF) that may impact the anatomy of related structures that traverse the cervical region, such as the vertebral artery (VA). This retrospective anatomical study utilized CT angiography cervical scans to examine the prevalence of DTF, VA, and TF areas. The subjects were separated into two groups: normal TF (NTF group; 26 males and 21 females) and double TF (DTF group; 21 males and 24 females). The males presented significantly higher TF area values (30.31 ± 4.52 mm2) than the females (27.48 ± 1.69 mm2) in the NTF group (p = 0.006). The sex differences disappeared when a DTF was present (p = 0.662). There were no differences in the VA area values between the sexes in both the NTF and DTF groups (p = 0.184). No significant differences in the VA area values between males of the NTF and DTF groups (p = 0.485) were noted. The DTF subjects presented an increased VA/TF area ratio than the NTF subjects (p &...
Effect of APOE4 Allele and Gender on the Rate of Atrophy in the Hippocampus, Entorhinal Cortex, and Fusiform Gyrus in Alzheimer’s Disease
Current Alzheimer Research
Background: The hippocampus, entorhinal cortex, and fusiform gyrus are brain areas that deteriora... more Background: The hippocampus, entorhinal cortex, and fusiform gyrus are brain areas that deteriorate during early-stage Alzheimer’s disease (AD). The ApoE4 allele has been identified as a risk factor for AD development, is linked to an increase in the aggregation of amyloid ß (Aß) plaques in the brain, and is responsible for atrophy of the hippocampal area. However, to our knowledge, the rate of deterioration over time in individuals with AD, with or without the ApoE4 allele, has not been investigated. Method: In this study, we, for the first time, analyze atrophy in these brain structures in AD patients with and without the ApoE4 using the Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset. Results: It was found that the rate of decrease in the volume of these brain areas over 12 months was related to the presence of ApoE4. Further, we found that neural atrophy was not different for female and male patients, unlike prior studies, suggesting that the presence of ApoE4 is not ...
Homo naledi lumbar vertebrae and a new 3D method to quantify vertebral wedging
American Journal of Biological Anthropology
ObjectivesIn humans and known fossil hominins, lumbar lordosis is produced by vertebral body wedg... more ObjectivesIn humans and known fossil hominins, lumbar lordosis is produced by vertebral body wedging and other bony and soft tissue features such as the shape of the intervertebral discs. Current techniques for quantifying the wedging of vertebral bodies are limited in utility, especially when analyzing incomplete fossil material. Here, we introduce a 3D method to quantify vertebral body wedging angles that yields the angles between two “best fit” planes in the software GeoMagic Wrap (3D Systems).Materials and MethodsTo test that this new method is repeatable with existing methods, we measure the wedging of 320 lumbar vertebrae representing 64 modern human individuals. For each vertebra, wedging angles were calculated from linear measurements taken with calipers and compared with estimates generated from the 3D best fit plane method. We also apply the 3D plane method to fossil hominin lumbar vertebrae, including newly described lumbar vertebrae of Homo naledi, the majority of which ...
The Vertebrae, Ribs, and Sternum of Australopithecus sediba: Special Issue: Australopithecus sediba
Paleoanthropology, Dec 31, 2018
Australopithecus sediba is known from two partial skeletons, Malapa Hominins 1 and 2 (MH1 and MH2... more Australopithecus sediba is known from two partial skeletons, Malapa Hominins 1 and 2 (MH1 and MH2), a juvenile male and an adult female, respectively. Forty-eight elements of the axial skeleton, including vertebrae, ribs, a sternum, and a sacrum, are known from MH1 and MH2. Here, we describe these ~2.0 Ma fossils and provide raw data and plots of standardized measurements. We revisit the serial positions of the previously described vertebrae and ribs proposed in their initial announcements and provide revised identifications. Additionally, we include in our descriptions and analyses new axial material. Finally, we also test the hypothesis that multiple species are represented in the MH1 and MH2 material and specifically that MH1’s lumbar vertebrae belong to a member of the genus Homo, whereas those of MH2 belong to Australopithecus. We do not find support for this hypothesis, and instead attribute differences between MH1 and MH2 to their age difference and incomplete growth of the vertebral body in juvenile MH1.
Quaternary International, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
A pilot study on the uncovertebral joints and their degenerative changes in the aetiology of cervical spondylosis
The Foot, 2018
Background: The dorsalis pedis artery is responsible for blood supply to the dorsal aspect of the... more Background: 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.
African Vision and Eye Health
Background: Corneal changes occur as a direct consequence of diabetes mellitus (DM). The central ... more Background: Corneal changes occur as a direct consequence of diabetes mellitus (DM). The central corneal thickness (CCT) is a useful parameter that provides information about the status of the metabolism of the cornea and can therefore help monitor the progression of DM.Aim: The aim of this study was to determine the impact of DM on CCT and its correlation with diabetes duration and glycated haemoglobin (HbA1c) levels.Methods: The systematic review was undertaken to answer: (1) What effect does DM have on CCT values? (2) What effect does DM duration have on CCT values? (3) What effect does HbA1c levels have on CCT values? The Web of Science was used to conduct a computerised search for articles of CCT values in DM.Results: A total of 38 articles that met the criteria for inclusion were included in this systemic review. The researchers found 27 articles that observed increased CCT values in DM patients compared with control subjects. There were six studies in which increased CCT valu...
Differences in gonial angle values between Chalcolithic and present subjects
Hallux Valgus and 1st Metatarsal head Morphology - a South African Study
Thoracolumbar vertebrae and ribs
Hominin Postcranial Remains from Sterkfontein, South Africa, 1936-1995, 2020
This chapter describes and presents analysis of all vertebrae and ribs for the Sterkfontein homin... more This chapter describes and presents analysis of all vertebrae and ribs for the Sterkfontein hominins, including those associated with the Sts 14 and 431 skeletons. New rib fragments recently identified and accessioned with Sts 14 are included. Taken together, the vertebrae and ribs of the Sterkfontein hominins tell a consistent story. With one exception from Member 5 that may be attributable to Homo, all other specimens are consistent with being attributed to the same species, likely Australopithecus africanus. Overall, all the Sterkfontein specimens resemble those from other early hominins, reflecting a fundamentally human-like torso, with a series of sinusoidal spinal curvatures similar to those of hominins. These characteristics are distinctly human-like, are dissimilar from any other mammal, and are consistent with a fully upright posture. Sts 14 also displays two common spinal pathologies seen in humans but not in other hominoids, associated with the sinusoidal spinal curvature...
South African Journal of Science, 2016
First ribs - the first or most superior ribs in the thorax - are rare in the hominin fossil recor... more 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 grea...
eLife, 2015
Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Cha... more Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.
Supplementary Materials for
A New Species of Canid from the Malapa Hominin Site, Gauteng, South Africa
ABSTRACT The recently discovered hominin bearing site of Malapa (Gauteng South Africa), type loca... more ABSTRACT The recently discovered hominin bearing site of Malapa (Gauteng South Africa), type locality for Australopithecus sediba, has yielded a mammalian fossil assemblage that is remarkable in both its taxonomic breadth and preservational quality. Many of the species that have been identified from this assemblage are represented by multiple elements from single individuals – a rarity for the South African fossil record. Numerous specimens of carnivorans have also been described from the site including both large and small species. Here we examine a smaller sample of specimens that represent the second new species (after A. sediba) to emerge from the 1.977 million year old Malapa sample – a new small canid that we attribute to the genus Vulpes. The type specimen, University of the Witwatersrand (UW) 88-812 is a right mandibular fragment that includes part of the alveolus of the p3, the complete p4 and m1, the alveoli of m2 and m3 and the entire distal portion of the mandible. The coronoid, condylar and angular processes as well as mandibular foramen and masticatory muscle insertion scars are well preserved. Another specimen (UW 88-814) is a complete right m2 crown that we believe is from the same individual. Likewise, a complete right rib (UW 88-813) from a small canid was also recovered from the same breccia block. Given the preservational state of Malapa (almost no taphonomic mixing of the sample), this specimen likely came from the same individual. Relative to a large sample of individuals of modern and fossil Vulpes as well as other small canid genera (which can be excluded based on morphology), the new Malapa species of Vulpes is defined by the lack of distal accessory cusp on its p4, mesiodistally compressed and high-crowned m1 trigonid, relatively large m2, and relatively small condyle. Overall, this new species is gracile with high-crowned sharp teeth, suggesting, despite its lack of accessory cusps, a tendency toward hypercarnivory or insectivory.
A new species of fox from theAustralopithecus sedibatype locality, Malapa, South Africa
Transactions of the Royal Society of South Africa, 2013
ABSTRACT The 1.977 Ma site of ‘Malapa’ (Gauteng, South Africa) has yielded important new fossils,... more ABSTRACT The 1.977 Ma site of ‘Malapa’ (Gauteng, South Africa) has yielded important new fossils, including the type specimens of the new hominin species Australopithecus sediba. Recently, we reported the first Carnivora specimens to have been recovered from the site. That sample included members of Felidae, Herpestidae and Hyaenidae. That first report also included three associated small canid specimens (an M2, a rib and a posterior mandibular fragment including the P4, M1, coronoid, condylar and angular processes) that we attributed to Vulpes cf. V. chama. In this paper, we compare these specimens to a broad sample of modern and fossil foxes and conclude that these specimens are distinct enough to be referred to a new species, here described and named Vulpes skinneri.
Science, 2013
of early hominin fossils on the continent of Africa. The fossil remains of Au. sediba were discov... more of early hominin fossils on the continent of Africa. The fossil remains of Au. sediba were discovered in August of 2008, and the species was named in 2010 (1)* and given a provisional age of ~1.78 to 1.95 Ma (2). In 2011, detailed studies of four critical areas of anatomy of these remains were published (3-6), and a refi ned date of ~1.977 to 1.98 Ma was proposed (7). The six articles presented in full in the online edition of Science (www.sciencemag.org/site/extra/sediba), with abstracts in print (pp. 164-165), complete the initial examination of the prepared material attributed to three individuals: the holotype and paratype skeletons, commonly referred to as MH1 and MH2, and the adult isolated tibia referred to as MH4. They, along with the cumulative research published over the past 3 years, provide us with a comprehensive examination of the anatomy of a single species of early hominin. Irish et al. examine highly heritable nonmetric dental traits in Au. sediba. The species appears phylogenetically distinct from East African australopiths but close to Au. africanus, forming a southern African australopith clade. The latter shares some derived states with a clade comprising four fossil samples of the genus Homo. This result has implications for our present understanding of hominin phylogeny through the terminal Pliocene and suggests a possibility that Au. sediba, and perhaps Au. africanus, did not descend from the Au. afarensis lineage. De Ruiter et al. examine mandibular material attributable to MH2, including the previously unknown mandibular incisors and premolars of Au. sediba. As seen elsewhere in the cranium and skeleton, these mandibular remains share similarities with those of other australopiths but differ from Au. africanus in both size and shape, as well as in their ontogenetic growth trajectory. These results further support the claim that Au. sediba is taxonomically distinct from Au. africanus. Where the Au. sediba mandibles differ from those of Au. africanus, they appear most similar to those of representatives of early Homo. Churchill et al. explore the upper limb elements of Au. sediba, describing the most complete and undistorted humerus, radius, ulna, scapula, clavicle, and manubrium yet described from the early hominin record, all associated with one individual. With the exception of the hand skeleton (3), the upper limbs of the Malapa hominins are largely primitive in their morphology. Au. sediba thus shares with other australopiths an upper limb that was well suited for arboreal climbing and possibly suspension, although perhaps more so than has previously been suggested for this genus.
Science, 2013
The shape of the thorax of early hominins has been a point of contention for more than 30 years. ... more The shape of the thorax of early hominins has been a point of contention for more than 30 years. Owing to the generally fragmentary nature of fossil hominin ribs, few specimens have been recovered that have rib remains complete enough to allow accurate reassembly of thoracic shape, thus leaving open the question of when the cylindrical-shaped chest of humans and their immediate ancestors evolved. The ribs of Australopithecus sediba exhibit a mediolaterally narrow, ape-like upper thoracic shape, which is unlike the broad upper thorax of Homo that has been related to the locomotor pattern of endurance walking and running. The lower thorax, however, appears less laterally flared than that of apes and more closely approximates the morphology found in humans.
Geometric morphometrics of hominoid thoraces and its bearing for reconstructing the ribcage of H. naledi
H. naledi shows a mosaic morphological pattern with several derived (Homo-like) features of the s... more H. naledi shows a mosaic morphological pattern with several derived (Homo-like) features of the skull, hands and feet, and primitive (australopith- like) features in the ribcage, shoulder, and pelvis. This pattern reflects a morphology that might be expected of a hominin at the evolutionary transition between Australopithecus and Homo. Two thoracic vertebrae from levels 10 and 11 and the proximal aspect of an 11th rib were found in near anatomical connection in the Dinaledi Chamber of Rising Star cave, therefore likely belonging to the same individual. In this study we explore this association and report our ongoing work towards a quantitative 3D reconstruction of the H. naledi thorax. We measured 512 3D-(semi)landmarks on human and other hominoid ribcages (hylobatids, Pongo, Gorilla, Pan; N=33) for geometric morphometric analyses. Covariation between the 11th rib and remaining thorax shape was analyzed by partial least squares analysis (PLS) and overall thorax variation by principal components analysis (PCA). PCA results show wide ranges of complex thoracic variation. Gorilla and Pan are characterized by highly constricted upper thoraces when compared to their wide lower ribcages. Pongo and hylobatids have less narrow upper but also wide lower thoraces. Those of humans are expanded superiorly, narrow inferiorly, and with declined ribs. PLS analyses suggest that the morphology of the articulated rib-vertebra complex at the 11th level of H. naledi is compatible with a ribcage with declined ribs and inferiorly wider than observed in humans. This corresponds with evidence for laterally flared iliac blades of the H. naledi pelvis.
H. naledi shows a mosaic morphological pattern with several derived (Homo-like) features of the s... more H. naledi shows a mosaic morphological pattern
with several derived (Homo-like) features of the
skull, hands and feet, and primitive (australopith-
like) features in the ribcage, shoulder, and
pelvis. This pattern reflects a morphology that
might be expected of a hominin at the evolutionary
transition between Australopithecus and
Homo. Two thoracic vertebrae from levels 10
and 11 and the proximal aspect of an 11th rib
were found in near anatomical connection in
the Dinaledi Chamber of Rising Star cave, therefore
likely belonging to the same individual.
In this study we explore this association and
report our ongoing work towards a quantitative
3D reconstruction of the H. naledi thorax. We
measured 512 3D-(semi)landmarks on human
and other hominoid ribcages (hylobatids, Pongo,
Gorilla, Pan; N=33) for geometric morphometric
analyses. Covariation between the 11th rib and
remaining thorax shape was analyzed by partial
least squares analysis (PLS) and overall thorax
variation by principal components analysis
(PCA). PCA results show wide ranges of complex
thoracic variation. Gorilla and Pan are characterized
by highly constricted upper thoraces when
compared to their wide lower ribcages. Pongo and
hylobatids have less narrow upper but also wide
lower thoraces. Those of humans are expanded
superiorly, narrow inferiorly, and with declined
ribs. PLS analyses suggest that the morphology
of the articulated rib-vertebra complex at the 11th
level of H. naledi is compatible with a ribcage with
declined ribs and inferiorly wider than observed
in humans. This corresponds with evidence for
laterally flared iliac blades of the H. naledi pelvis.