TY - JOUR
T1 - Trabecular organization of the proximal femur in Paranthropus robustus
T2 - Implications for the assessment of its hip joint loading conditions
AU - Cazenave, Marine
AU - Oettlé, Anna
AU - Pickering, Travis Rayne
AU - Heaton, Jason L.
AU - Nakatsukasa, Masato
AU - Francis Thackeray, J.
AU - Hoffman, Jakobus
AU - Macchiarelli, Roberto
N1 - Funding Information:
For access to fossil and comparative materials, we are grateful to the curatorial staff of the Ditsong National Museum of Natural History, Pretoria; the Evolutionary Studies Institute and the R.A. Dart Collection at the University of the Witwatersrand, Johannesburg; the McGregor Museum of Kimberley; the Museum national d’Histoire naturelle (MNHN), Paris; the Pretoria Bone Collection at the Department of Anatomy of the University of Pretoria; I. Livne (Birchington-on-Sea) for access to the gorilla sample of the Powell-Cotton Museum and M. Skinner (Canterbury) and T. Kivell (Canterbury) for sharing the μXCT data; and M. Nakamura (Kyoto) and Y. Shintaku (Inuyama) for permission to access Mahale chimpanzee collection. For the extant human comparative sample, ethical clearance was obtained from the Faculty of Health Sciences Research Ethics committee of the University of Pretoria (ref. no. 39/2016). We especially acknowledge B. Billing (Johannesburg), L. Kgasi (Pretoria), D. Morris (Kimberley), S. Potze (Pretoria), M. Tawane (Pretoria) and B. Zipfel (Johannesburg). For the scanning procedure of the Pan sample from the MNHN (UMR 7194 CNRS 2018–2020 grants to R.M.) we thank the staff and especially M. Bellato from the AST-RX, plateau d’Accès Scientifique à la Tomographie à Rayons X du MNHN, UMS 2700 2AD CNRS-MNHN, Paris. We thank L. Bam (Pelindaba), K. Jakata (Johannesburg), and R. Kono (Yokohama) for μXCT scanning at Necsa, Wits, and Tokyo, respectively. Acquisitions at the ESRF were performed by R.M. within the EC TNT project in collaboration with A. Mazurier (Poitiers). For scientific collaboration and availability to run independent measures for interobserver error assessment, we thank A. Beaudet (Johannesburg), A. Mazurier and C. Zanolli (Bordeaux). For discussion, we thank A. Beaudet, J. Braga (Toulouse), L. Bruxelles (Johannesburg and Toulouse), K. Carlson (Johannesburg and Los Angeles), R.J. Clarke (Johannesburg), J. Dumoncel (Toulouse), C. Dunmore (Canterbury), F.E. Grine (Stony Brook), T. Kivell, D. Marchi (Pisa), E. Pouydebat (Paris), M. Skinner, C. Theye (Pretoria), C. Zanolli and B. Zipfel. Finally, we are grateful to David Alba, the Associate Editor, and to three anonymous reviewers for constructive critique that considerably improved this manuscript. We acknowledge the DST-NRF for financial support (Grant # UID23456 ) to establish the MIXRAD microfocus X-ray tomography facility at Necsa. M.C. was funded by the European Commission (EACEA), Erasmus Mundus programme , AESOP and AESOP + consortia co-ordinated by J. Braga, by the Erasmus Mundus programme, Bakeng se Afrika and by the Fyssen Foundation.
Funding Information:
For access to fossil and comparative materials, we are grateful to the curatorial staff of the Ditsong National Museum of Natural History, Pretoria; the Evolutionary Studies Institute and the R.A. Dart Collection at the University of the Witwatersrand, Johannesburg; the McGregor Museum of Kimberley; the Museum national d'Histoire naturelle (MNHN), Paris; the Pretoria Bone Collection at the Department of Anatomy of the University of Pretoria; I. Livne (Birchington-on-Sea) for access to the gorilla sample of the Powell-Cotton Museum and M. Skinner (Canterbury) and T. Kivell (Canterbury) for sharing the μXCT data; and M. Nakamura (Kyoto) and Y. Shintaku (Inuyama) for permission to access Mahale chimpanzee collection. For the extant human comparative sample, ethical clearance was obtained from the Faculty of Health Sciences Research Ethics committee of the University of Pretoria (ref. no. 39/2016). We especially acknowledge B. Billing (Johannesburg), L. Kgasi (Pretoria), D. Morris (Kimberley), S. Potze (Pretoria), M. Tawane (Pretoria) and B. Zipfel (Johannesburg). For the scanning procedure of the Pan sample from the MNHN (UMR 7194 CNRS 2018–2020 grants to R.M.) we thank the staff and especially M. Bellato from the AST-RX, plateau d'Accès Scientifique à la Tomographie à Rayons X du MNHN, UMS 2700 2AD CNRS-MNHN, Paris. We thank L. Bam (Pelindaba), K. Jakata (Johannesburg), and R. Kono (Yokohama) for μXCT scanning at Necsa, Wits, and Tokyo, respectively. Acquisitions at the ESRF were performed by R.M. within the EC TNT project in collaboration with A. Mazurier (Poitiers). For scientific collaboration and availability to run independent measures for interobserver error assessment, we thank A. Beaudet (Johannesburg), A. Mazurier and C. Zanolli (Bordeaux). For discussion, we thank A. Beaudet, J. Braga (Toulouse), L. Bruxelles (Johannesburg and Toulouse), K. Carlson (Johannesburg and Los Angeles), R.J. Clarke (Johannesburg), J. Dumoncel (Toulouse), C. Dunmore (Canterbury), F.E. Grine (Stony Brook), T. Kivell, D. Marchi (Pisa), E. Pouydebat (Paris), M. Skinner, C. Theye (Pretoria), C. Zanolli and B. Zipfel. Finally, we are grateful to David Alba, the Associate Editor, and to three anonymous reviewers for constructive critique that considerably improved this manuscript. We acknowledge the DST-NRF for financial support (Grant # UID23456) to establish the MIXRAD microfocus X-ray tomography facility at Necsa. M.C. was funded by the European Commission (EACEA), Erasmus Mundus programme, AESOP and AESOP + consortia co-ordinated by J. Braga, by the Erasmus Mundus programme, Bakeng se Afrika and by the Fyssen Foundation.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/4
Y1 - 2021/4
N2 - Reconstruction of the locomotor repertoire of the australopiths (Australopithecus and Paranthropus) has progressively integrated information from the mechanosensitive internal structure of the appendicular skeleton. Recent investigations showed that the arrangement of the trabecular network at the femoral head center is biomechanically compatible with the pattern of cortical bone distribution across the neck, both suggesting a full commitment to bipedalism in australopiths, but associated with a slightly altered gait kinematics compared to Homo involving more lateral deviation of the body center of mass over the stance limb. To provide a global picture in Paranthropus robustus of the trabecular architecture of the proximal femur across the head, neck and greater trochanter compartments, we applied techniques of virtual imaging to the variably preserved Early Pleistocene specimens SK 82, SK 97, SK 3121, SKW 19 and SWT1/LB-2 from the cave site of Swartkrans, South Africa. We also assessed the coherence between the structural signals from the center of the head and those from the trabecular network of the inferolateral portion of the head and the inferior margin of the neck, sampling the so-called vertical bundle, which in humans represents the principal compressive system of the joint. Our analyses show a functionally related trabecular organization in Pa. robustus that closely resembles the extant human condition, but which also includes some specificities in local textural arrangement. The network of the inferolateral portion of the head shows a humanlike degree of anisotropy and a bone volume fraction intermediate between the extant human and the African ape patterns. These results suggest slight differences in gait kinematics between Pa. robustus and extant humans. The neck portion of the vertical bundle revealed a less biomechanically sensitive signal. Future investigations on the australopith hip joint loading environment should more carefully investigate the trabecular structure of the trochanteric region and possible structural covariation between cortical bone distribution across the neck and site-specific trabecular properties of the arcuate bundle.
AB - Reconstruction of the locomotor repertoire of the australopiths (Australopithecus and Paranthropus) has progressively integrated information from the mechanosensitive internal structure of the appendicular skeleton. Recent investigations showed that the arrangement of the trabecular network at the femoral head center is biomechanically compatible with the pattern of cortical bone distribution across the neck, both suggesting a full commitment to bipedalism in australopiths, but associated with a slightly altered gait kinematics compared to Homo involving more lateral deviation of the body center of mass over the stance limb. To provide a global picture in Paranthropus robustus of the trabecular architecture of the proximal femur across the head, neck and greater trochanter compartments, we applied techniques of virtual imaging to the variably preserved Early Pleistocene specimens SK 82, SK 97, SK 3121, SKW 19 and SWT1/LB-2 from the cave site of Swartkrans, South Africa. We also assessed the coherence between the structural signals from the center of the head and those from the trabecular network of the inferolateral portion of the head and the inferior margin of the neck, sampling the so-called vertical bundle, which in humans represents the principal compressive system of the joint. Our analyses show a functionally related trabecular organization in Pa. robustus that closely resembles the extant human condition, but which also includes some specificities in local textural arrangement. The network of the inferolateral portion of the head shows a humanlike degree of anisotropy and a bone volume fraction intermediate between the extant human and the African ape patterns. These results suggest slight differences in gait kinematics between Pa. robustus and extant humans. The neck portion of the vertical bundle revealed a less biomechanically sensitive signal. Future investigations on the australopith hip joint loading environment should more carefully investigate the trabecular structure of the trochanteric region and possible structural covariation between cortical bone distribution across the neck and site-specific trabecular properties of the arcuate bundle.
KW - Hominin biomechanics
KW - Proximal femur
KW - South Africa
KW - Swartkrans
KW - Trabecular pattern
KW - X-ray microtomography
UR - http://www.scopus.com/inward/record.url?scp=85103360195&partnerID=8YFLogxK
U2 - 10.1016/j.jhevol.2021.102964
DO - 10.1016/j.jhevol.2021.102964
M3 - Article
C2 - 33713985
AN - SCOPUS:85103360195
VL - 153
JO - Journal of Human Evolution
JF - Journal of Human Evolution
SN - 0047-2484
M1 - 102964
ER -