Section: Paleontology
Topic: Evolution, Paleontology, Anthropology

OH 89: A newly described ~1.8-million-year-old hominid clavicle from Olduvai Gorge

10.24072/pcjournal.372 - Peer Community Journal, Volume 4 (2024), article no. e34.

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Objectives Here, we describe the morphology and geologic context of OH 89, a ∼1.8million-year-old partial hominid clavicle from Olduvai (Oldupai) Gorge, Tanzania. We compare the morphology and clavicular curvature of OH 89 to modern humans, extant apes, and a sample of other hominid fossil clavicles. Materials and Methods Comparative samples include 25 modern human clavicles, 30 Gorilla, 31 Pan, 7 Papio, and five hominid clavicles. Length regression on midshaft size using the extant comparative samples is used to estimate the total length of OH 89. A set of 9 linear measurements are taken from each individual. We also describe a new methodology for measuring clavicular curvature using measurements of sternal and acromial curvature, from which an overall curvature measurement is calculated. A principal component analysis (PCA) and a t-distributed stochastic neighbor embedding (tSNE) analysis are used to compare the morphology of OH 89 with the extant and fossil comparative samples. Results Our new method of measuring clavicular curvature successfully separates the different genera of the extant clavicles. The length estimate and sternal and acromial curve measurements for OH 89 falls within the larger male humans. The PCA shows OH 89 and most of the fossil hominids falling between the modern human and Pan groups, while the t-SNE suggests that OH 89, KSD-VP-1/1, KNM-ER 1808, and OH 48 are more similar to each other than to any of the other groups. This analysis also plots KNM-WT 15000 with the modern humans and Krapina 158 with the Pan individuals. Discussion The OH 89 clavicle derives from an individual of unknown hominid species with a shoulder breadth similar to that of a large human male. The curvature of OH 89 is relatively human-like relative to its length. Our new methodology for measuring clavicular curvature, combined with the utilization of t-SNE analyses and comparison of t-SNE results to PCA results, provides greater separation of genera than previously used methods, and wider use of t-SNE may be useful in paleoanthropological work.

Published online:
DOI: 10.24072/pcjournal.372
Type: Research article
Keywords: paleontology, evolution, paleoanthropology, Pleistocene, variation
Taylor, Catherine E 1; Masao, Fidelis 2, 3; Njau, Jackson K 4, 5; Songita, Agustino Venance 3; Hlusko, Leslea J 1, 6

1 Human Evolution Research Center, University of California Berkeley – Berkeley, CA, USA
2 University of Dar es Salaam – Dar es Salaam, Tanzania
3 Conservation Olduvai Project – Dar es Salaam, Tanzania
4 Department of Earth and Atmospheric Sciences, Indiana University – Bloomington, Indiana, USA
5 The Stone Age Institute – Bloomington, Indiana, USA
6 Centro Nacional de Investigación sobre la Evolución Humana – Burgos, Spain
License: CC-BY 4.0
Copyrights: The authors retain unrestricted copyrights and publishing rights
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Taylor, Catherine E; Masao, Fidelis; Njau, Jackson K; Songita, Agustino Venance; Hlusko, Leslea J. OH 89: A newly described ~1.8-million-year-old hominid clavicle from Olduvai Gorge. Peer Community Journal, Volume 4 (2024), article  no. e34. doi : 10.24072/pcjournal.372. https://peercommunityjournal.org/articles/10.24072/pcjournal.372/

Peer reviewed and recommended by PCI : 10.24072/pci.paleo.100218

Conflict of interest of the recommender and peer reviewers:
The recommender in charge of the evaluation of the article and the reviewers declared that they have no conflict of interest (as defined in the code of conduct of PCI) with the authors or with the content of the article.

[1] Abdel Fatah, E.; Shirley, N.; Mahfouz, M.; Auerbach, B. A Three- Dimensional Analysis of Bilateral Directional Asymmetry in the Human Clavicle, American journal of physical anthropology, Volume 149 (2012) no. 4, pp. 547-559 | DOI

[2] Alemseged, Z.; Spoor, F.; Kimbel, W.; Bobe, R.; Geraads, D.; Reed, D.; Wynn, J. A Juvenile Early Hominin Skeleton from Dikika, Ethiopia, Nature, Volume 443 (2006) no. 7109, pp. 296-301 | DOI

[3] Arora, S.; Hu, W.; Kothari, P. Conference on Learning Theory, Proceedings of the 31st Conference On Learning Theory, PMLR (2018), pp. 1455-1462 (https://proceedings.mlr.press/v75/arora18a.html)

[4] Auerbach, B.; Raxter, M. Patterns of Clavicular Bilateral Asymmetry in Relation to the Humerus: Variation among Humans, Journal of human evolution, Volume 54 (2008) no. 5, pp. 663-674 | DOI

[5] Barros, A. Ontogeny, Phylogeny and Functional Morphology of the Hominoid Shoulder Girdle, University College London (2014) (https://discovery.ucl.ac.uk/id/eprint/1447948/)

[6] Bernat, A.; Huysmans, T.; Glabbeek, F.; Sijbers, J.; Gielen, J.; Tongel, A. The Anatomy of the Clavicle: A Three-dimensional Cadaveric Study, Clinical anatomy, Volume 27 (2014) no. 5, pp. 712-723 | DOI

[7] Black, S.; Scheuer, L. Age Changes in the Clavicle: From the Early Neonatal Period to Skeletal Maturity, International Journal of Osteoarchaeology, Volume 6 (1996) no. 5, pp. 425-434 | DOI

[8] Blumenschine, R.; Stanistreet, I.; Masao, F. Olduvai Gorge and the Olduvai Landscape Paleoanthropology Project, Journal of human evolution, Volume 63 (2012) no. 2, pp. 247-250 | DOI

[9] Carlson, K.; Green, D.; Jashashvili, T.; Pickering, T.; Heaton, J.; Beaudet, A.; Clarke, R. The Pectoral Girdle of StW 573 (`Little Foot') and Its Implications for Shoulder Evolution in the Hominina, Journal of Human Evolution, Volume 102983 (2021) | DOI

[10] Carretero, J. M.; Arsuaga, J. L.; Lorenzo, C. Clavicles, scapulae and humeri from the Sima de los Huesos site (Sierra de Atapuerca, Spain), Journal of Human Evolution, Volume 33 (1997) no. 2-3, pp. 357-408 | DOI

[11] Clarke, R. A Homo Habilis Maxilla and Other Newly-Discovered Hominid Fossils from Olduvai Gorge, Tanzania, Journal of Human Evolution, Volume 63 (2012) no. 2, pp. 418-428 | DOI

[12] de la Cova, C. Marginalized bodies and the construction of the Robert J. Terry anatomical skeletal collection, Bioarchaeology of Marginalized People, Elsevier, 2019, pp. 133-155 | DOI

[13] Daruwalla, Z. J.; Courtis, P.; Fitzpatrick, C.; Fitzpatrick, D.; Mullett, H. Anatomic variation of the clavicle: A novel three‐dimensional study, Clinical Anatomy, Volume 23 (2010) no. 2, pp. 199-209 | DOI

[14] Day, M. H. Early Homo sapiens Remains from the Omo River Region of South-west Ethiopia: Omo Human Skeletal Remains, Nature, Volume 222 (1969) no. 5199, pp. 1135-1138 | DOI

[15] Day, M.; Scheuer, J. Olduvai Hominid 48: A Clavicle, Human Biology Budapest, Volume 19 (1989), pp. 9-14

[16] Deino, A. L. 40Ar/39Ar dating of Bed I, Olduvai Gorge, Tanzania, and the chronology of early Pleistocene climate change, Journal of Human Evolution, Volume 63 (2012) no. 2, pp. 251-273 | DOI

[17] Deino, A. L.; Heil, C.; King, J.; McHenry, L. J.; Stanistreet, I. G.; Stollhofen, H.; Njau, J. K.; Mwankunda, J.; Schick, K. D.; Toth, N. Chronostratigraphy and age modeling of Pleistocene drill cores from the Olduvai Basin, Tanzania (Olduvai Gorge Coring Project), Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 571 (2021) | DOI

[18] Diez-Martín, F.; Sánchez Yustos, P.; Uribelarrea, D.; Baquedano, E.; Mark, D. F.; Mabulla, A.; Fraile, C.; Duque, J.; Díaz, I.; Pérez-González, A.; Yravedra, J.; Egeland, C. P.; Organista, E.; Domínguez-Rodrigo, M. The Origin of The Acheulean: The 1.7 Million-Year-Old Site of FLK West, Olduvai Gorge (Tanzania), Scientific Reports, Volume 5 (2015) no. 1 | DOI

[19] Dirks, P. H. G. M.; Kibii, J. M.; Kuhn, B. F.; Steininger, C.; Churchill, S. E.; Kramers, J. D.; Pickering, R.; Farber, D. L.; Mériaux, A.-S.; Herries, A. I. R.; King, G. C. P.; Berger, L. R. Geological setting and age of Australopithecus sediba from southern Africa, Science, Volume 328 (2010) no. 5975, pp. 205-208 | DOI

[20] Domínguez-Rodrigo, M.; Pickering, T. R.; Almécija, S.; Heaton, J. L.; Baquedano, E.; Mabulla, A.; Uribelarrea, D. Earliest modern human-like hand bone from a new >1.84-million-year-old site at Olduvai in Tanzania, Nature Communications, Volume 6 (2015) no. 1 | DOI

[21] Drapeau, M.; Ward, C.; Kimbel, W.; Johanson, D.; Rak, Y. Associated Cranial and Forelimb Remains Attributed to Australopithecus Afarensis from Hadar, Ethiopia, Journal of Human Evolution, Volume 48 (2005) no. 6, pp. 593-642 | DOI

[22] Fernandez-Jalvo, Y.; Carlos Diez, J.; Caceres, I.; Rosell, J. Human cannibalism in the Early Pleistocene of Europe (Gran Dolina, Sierra de Atapuerca, Burgos, Spain), Journal of Human Evolution, Volume 37 (1999) no. 3-4, pp. 591-622 | DOI

[23] Feuerriegel, E.; Green, D.; Walker, C.; Schmid, P.; Hawks, J.; Berger, L.; Churchill, S. The upper limb of Homo naledi, Journal of Human Evolution, Volume 104 (2017), pp. 155-173 | DOI

[24] Garcia, N. A New Method for Measuring Clavicular Curvature, Peer Community in Paleontology, Volume 100218 (2023) | DOI

[25] García‐González, R.; Rodríguez, L.; Salazar‐Fernández, A.; Arsuaga, J. L.; Carretero, J. Updated study of adult and subadult pectoral girdle bones from Sima de los Huesos site (Sierra de Atapuerca, Burgos, Spain). Anatomical and age estimation keys, The Anatomical Record (2023) | DOI

[26] Green, D. J. Scapula, clavicle, and proximal humerus, Hominin Postcranial Remains from Sterkfontein, South Africa, 1936-1995, Oxford University Press, 2020, pp. 37-48 | DOI

[27] Gómez-Olivencia, A.; Quam, R.; Sala, N.; Bardey, M.; Ohman, J.; Balzeau, A. La Ferrassie 1: New Perspectives on a “Classic” Neandertal, Journal of Human Evolution, Volume 117 (2018), pp. 13-32 | DOI

[28] Haile-Selassie, Y.; Latimer, B.; Alene, M.; Deino, A.; Gibert, L.; Melillo, S.; Lovejoy, C. An Early Australopithecus Afarensis Postcranium from Woranso-Mille, Ethiopia, Proceedings of the National Academy of Sciences, Volume 107 (2010) no. 27, pp. 12121-12126 | DOI

[29] Hay, R. Olduvai Gorge: Stratigraphy, Age and Environments, Abstract of Communication at Geological Society Symposium: Geological Background to Fossil Man, 1975

[30] Heim, J. Les hommes fossils de La Ferrassie, II. Les squelettes d'adultes: squelettes de membres, Paris, 1982 (https://gallica.bnf.fr/ark:/12148/bpt6k33271664)

[31] Jenkins, F. A. The movement of the shoulder in claviculate and aclaviculate mammals, Journal of Morphology, Volume 144 (1974) no. 1, pp. 71-83 | DOI

[32] Jenkins, F. A.; Goslow, G. E. The functional anatomy of the shoulder of the savannah monitor lizard (Varanus exanthematicus), Journal of Morphology, Volume 175 (1983) no. 2, pp. 195-216 | DOI

[33] Krijthe, J. Rtsne: T-Distributed Stochastic Neighbor Embedding using Barnes-Hut Implementation, R package version 0.16, 2015 (https://github.com/jkrijthe/Rtsne)

[34] Larson, S. G. Evolutionary transformation of the hominin shoulder, Evolutionary Anthropology: Issues, News, and Reviews, Volume 16 (2007) no. 5, pp. 172-187 | DOI

[35] Lawrence, M.; Huber, W.; Pagès, H.; Aboyoun, P.; Carlson, M.; Gentleman, R.; Morgan, M. T.; Carey, V. J. Software for Computing and Annotating Genomic Ranges, PLoS Computational Biology, Volume 9 (2013) no. 8 | DOI

[36] Lordkipanidze, D.; Jashashvili, T.; Vekua, A.; León, M.; Zollikofer, C.; Rightmire, G.; Rook, L. Postcranial Evidence from Early Homo from Dmanisi, Georgia, Nature, Volume 449 (2007) no. 7160, pp. 305-310 | DOI

[37] Lovejoy, C. O.; McCollum, M. A. Spinopelvic pathways to bipedality: why no hominids ever relied on a bent-hip–bent-knee gait, Philosophical Transactions of the Royal Society B: Biological Sciences, Volume 365 (2010) no. 1556, pp. 3289-3299 | DOI

[38] Lovejoy, C. O.; Suwa, G.; Simpson, S. W.; Matternes, J. H.; White, T. D. The great divides: Ardipithecus ramidus reveals the postcrania of our last common ancestors with African apes, Science, Volume 326 (2009) no. 5949, pp. 73-106 | DOI

[39] Lovejoy, C.; Johanson, D.; Coppens, Y. Hominid Upper Limb Bones Recovered from the Hadar Formation: 1974–1977 Collections, American Journal of Physical Anthropology, Volume 57 (1982) no. 4, pp. 637-649 | DOI

[40] van der Maaten, L.; Hinton, G. Visualizing Data Using T-SNE, Journal of machine learning research, Volume 9 (2008) no. 11 (https://jmlr.org/papers/v9/vandermaaten08a.html)

[41] Matsuoka, T.; Ahlberg, P.; Kessaris, N.; Iannarelli, P.; Dennehy, U.; Richardson, W.; Koentges, G. Neural crest origins of the neck and shoulder, Nature, Volume 436 (2005) no. 7049, pp. 347-355 | DOI

[42] Mays, S.; Steele, J.; Ford, M. Directional Asymmetry in the Human Clavicle, International Journal of Osteoarchaeology, Volume 9 (1999) no. 1, pp. 18-28 | DOI

[43] McHenry, L.; Stanistreet, I. Tephrochronology of Bed II, Olduvai Gorge, Tanzania, and Placement of the Oldowan–Acheulean Transition, Journal of Human Evolution, Volume 120 (2018), pp. 7-18 | DOI

[44] Melillo, S.; Gunz, P.; Coqueugniot, H.; Reske, S.; Hublin, J. Structural Effects of Variation in the Human Clavicle, American Journal of Physical Anthropology, Volume 168 (2019) no. 4, pp. 687-704 | DOI

[45] Melillo, S. The shoulder girdle of KSD-VP-1/1, The postcranial anatomy of Australopithecus afarensis, Springer, Dordrecht, 2016, pp. 113-141 | DOI

[46] Mersey, B.; Brudvik, K.; Black, M.; Defleur, A. Neanderthal Axial and Appendicular Remains from Moula-Guercy, Ardèche, France, American journal of physical anthropology, Volume 152 (2013) no. 4, pp. 530-542 | DOI

[47] Nesbitt, S.; Turner, A.; Spaulding, M.; Conrad, J.; Norell, M. The theropod furcula, Journal of Morphology, Volume 270 (2009) no. 7, pp. 856-879 | DOI

[48] Njau, J. K.; Toth, N.; Schick, K.; Stanistreet, I. G.; McHenry, L. J.; Stollhofen, H. The Olduvai Gorge Coring Project: Drilling high resolution palaeoclimatic and palaeoenvironmental archives to constrain hominin evolution, Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 561 (2021) | DOI

[49] Ogata, S.; Uhthoff, H. The Early Development and Ossification of the Human Clavicle—an Embryologic Study, Acta Orthopaedica Scandinavica, Volume 61 (1990) no. 4, pp. 330-334 | DOI

[50] Olivier, G. Anthropologie de la clavicule, Bulletins et Mémoires de la Société d'Anthropologie de Paris, Volume 2 (1951) no. 4, pp. 121-157 | DOI

[51] Parsons, F. On the Proportions and Characteristics of the Modern English Clavicle, Journal of Anatomy, Volume 51 (1916) no. Pt 1, p. 71

[52] Pearson, O.; Royer, D.; Grine, F.; Fleagle, J. A Description of the Omo I Postcranial Skeleton, Including Newly Discovered Fossils, Journal of Human Evolution, Volume 55 (2008) no. 3, pp. 421-437 | DOI

[53] R. Core Team R: A Language and Environment for Statistical Computing, 2019 (https://www.R-project.org/)

[54] Radovčić, J.; Wolpoff, M. The Krapina Hominids: An Illustrated Catalog of Skeletal Collection, Mladost for Croatian Natural History Museum, Zagreb, 1988, p. 118

[55] Ray, L. Metrical and Non-metrical Features of the Clavicle of the Australian Aboriginal, American Journal of Physical Anthropology, Volume 17 (1959) no. 3, pp. 217-226 | DOI

[56] Roach, N.; Richmond, B. Clavicle Length, Throwing Performance and the Reconstruction of the Homo Erectus Shoulder, Journal of human evolution, Volume 80 (2015), pp. 107-113 | DOI

[57] Rosas, A.; Rodriguez-Perez, F.; Bastir, M.; Estalrrich, A.; Huguet, R.; García-Tabernero, A.; Rasilla, M. Adult Neandertal Clavicles from the El Sidrón Site (Asturias, Spain) in the Context of Homo Pectoral Girdle Evolution, Journal of human evolution, Volume 95 (2016), pp. 55-67 | DOI

[58] Schultz, A. Proportions, Variability and Asymmetries of the Long Bones of the Limbs and the Clavicles in Man and Apes, Human Biology, Volume 9 (1937) no. 3, pp. 281-328

[59] Senut, B.; Nakatsukasa, M.; Kunimatsu, Y.; Nakano, Y.; Takano, T.; Tsujikawa, H.; Shimizu, D.; Kagaya, M.; Ishida, H. Preliminary analysis of Nacholapithecus scapula and clavicle from Nachola, Kenya, Primates, Volume 45 (2004) no. 2, pp. 97-104 | DOI

[60] Shubin, N.; Daeschler, E. B.; Jenkins Jr, F. A. Origin of the Tetrapod Neck and Shoulder, Great Transformations in Vertebrate Evolution, University of Chicago Press, 2015, pp. 63-76 | DOI

[61] Sievert, C. Interactive Web-Based Data Visualization with R, Plotly, and Shiny, Chapman and Hall/CRC, 2020 | DOI

[62] Squires, K.; García Mancuso, R. Ethical challenges associated with the study and treatment of human remains in anthropological sciences in the 21st century, Revista Argentina de Antropología Biológica, Volume 23 (2021) no. 2 | DOI

[63] Squyres, N.; DeLeon, V. Clavicular Curvature and Locomotion in Anthropoid Primates: A 3D Geometric Morphometric Analysis, American journal of physical anthropology, Volume 158 (2015) no. 2, pp. 257-268 | DOI

[64] Stanistreet, I. G.; Stollhofen, H.; Deino, A. L.; McHenry, L. J.; Toth, N. P.; Schick, K. D.; Njau, J. K. New Olduvai Basin stratigraphy and stratigraphic concepts revealed by OGCP cores into the Palaeolake Olduvai depocentre, Tanzania, Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 554 (2020) | DOI

[65] Taylor, C. OH89RCode. , Figshare, 2023 | DOI

[66] Taylor, C.; Masao, F.; Njau, J.; Songita, A. V.; Hlusko, L. OH89Data.csv. Dataset, Figshare (2023) | DOI

[67] Trinkaus, E. The Shanidar 3 Neandertal, American Journal of Physical Anthropology, Volume 57 (1982) no. 1, pp. 37-60 | DOI

[68] Trinkaus, E. The Postcranial Dimensions of the La Chapelle-aux-saints 1 Neandertal, American Journal of Physical Anthropology, Volume 145 (2011) no. 3, pp. 461-468 | DOI

[69] Trinkaus, E.; Churchill, S.; Ruff, C. Postcranial Robusticity in Homo. II: Humeral Bilateral Asymmetry and Bone Plasticity, American journal of physical anthropology, Volume 93 (1994) no. 1, pp. 1-34 | DOI

[70] Trinkaus, E.; Holliday, T.; Auerbach, B. Neandertal Clavicle Length, Proceedings of the National Academy of Sciences, Volume 111 (2014) no. 12, pp. 4438-4442 | DOI

[71] Vandermeersch, B. Les Hommes Fossiles de Qafzel (Israel). Cahiers de Paleoanthropologie, Edition du C.N.R.S., Paris, 1981

[72] Voisin, J. Évolution de la morphologie claviculaire au sein du genre Homo. Conséquences architecturales et fonctionnelles sur la ceinture scapulaire, L'anthropologie, Volume 105 (2001) no. 4, pp. 449-468 | DOI

[73] Voisin, J. The Omo I Hominin Clavicle: Archaic or Modern?, Journal of human evolution, Volume 55 (2008) no. 3, pp. 438-443 | DOI

[74] Voisin, J. Clavicle, a neglected bone: Morphology and relation to arm movements and shoulder architecture in primates, The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology, Volume 288A (2006) no. 9, pp. 944-953 | DOI

[75] Walker, A.; Leakey, R.; Leakey, R. E. The nariokotome Homo erectus skeleton, Harvard University Press, 1993

[76] Walker, M.; Ortega, J.; Parmová, K.; López, M.; Trinkaus, E. Morphology, Body Proportions, and Postcranial Hypertrophy of a Female Neandertal from the Sima de Las Palomas, Southeastern Spain, Proceedings of the National Academy of Sciences, Volume 108 (2011) no. 25, pp. 10087-10091 | DOI

[77] Walker, P. L. Bioarchaeological Ethics: A Historical Perspective on the Value of Human Remains In: Biological Anthropology of the Human Skeleton, Wiley, New York (2007), pp. 3-40 | DOI

[78] White, T. D.; Lovejoy, C. O.; Asfaw, B.; Carlson, J. P.; Suwa, G. Neither chimpanzee nor human, Ardipithecus reveals the surprising ancestry of both, Proceedings of the National Academy of Sciences, Volume 112 (2015) no. 16, pp. 4877-4884 | DOI

[79] Wickham, H. ggplot2: elegant graphics for data analysis, Springer, 2016 | DOI

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