1
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Falk D, Marom A. The DNH 7 endocast of Paranthropus robustus from Drimolen, South Africa: Reconsidering the functional significance of an enlarged occipital-marginal (O/M) sinus system in robust australopithecines. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 185:e25010. [PMID: 39150888 DOI: 10.1002/ajpa.25010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 07/08/2024] [Accepted: 07/25/2024] [Indexed: 08/18/2024]
Abstract
This paper presents a detailed analysis of the endocast of one of the most complete Paranthropus robustus crania known, DNH 7, from the Drimolen site (South Africa), and compares it with the morphology of other australopithecine endocasts. We focus on endocranial volume, the impressions of cortical sulci, cranial sutures, and the pattern of cranial venous sinuses on the endocast. A noteworthy observation is the estimated endocranial capacity of 403 cm3, which is small for an adult Paranthropus. Fragmentary sulci identified in the frontal and temporal lobes of DNH 7 exhibit similarities with patterns observed in chimpanzees and gracile australopithecines. We observe the presence of a large remnant of an occipital-marginal sinus on DNH 7 and provide an updated table of 13 Paranthropus endocasts that are scorable for this trait, which reinforces the hypothesis that an enlarged occipital-marginal (O/M) sinus system was fixed across the three species of Paranthropus. In light of this, the possible functional significance of the occipital-marginal sinus system is reevaluated considering the ontogenetic development of cranial venous blood flow in human children. This leads us to hypothesize that the ontogenetic development of cranial blood flow in Paranthropus and Australopithecus africanus infants were different and to suggest that Taung 1 was the only A. africanus specimen known to have exhibited an enlarged O/M sinus system because it was an immature individual.
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Affiliation(s)
- Dean Falk
- Department of Anthropology, Florida State University, Tallahassee, Florida, USA
| | - Assaf Marom
- Department of Neuroscience, The Farkas Family Center for Anatomical Research and Education, Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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2
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Martin JM, Leece AB, Baker SE, Herries AIR, Strait DS. A lineage perspective on hominin taxonomy and evolution. Evol Anthropol 2024; 33:e22018. [PMID: 38217397 DOI: 10.1002/evan.22018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 12/16/2023] [Accepted: 12/18/2023] [Indexed: 01/15/2024]
Abstract
An uncritical reliance on the phylogenetic species concept has led paleoanthropologists to become increasingly typological in their delimitation of new species in the hominin fossil record. As a practical matter, this approach identifies species as diagnosably distinct groups of fossils that share a unique suite of morphological characters but, ontologically, a species is a metapopulation lineage segment that extends from initial divergence to eventual extinction or subsequent speciation. Working from first principles of species concept theory, it is clear that a reliance on morphological diagnosabilty will systematically overestimate species diversity in the fossil record; because morphology can evolve within a lineage segment, it follows that early and late populations of the same species can be diagnosably distinct from each other. We suggest that a combination of morphology and chronology provides a more robust test of the single-species null hypothesis than morphology alone.
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Affiliation(s)
- Jesse M Martin
- Palaeoanthropology Lab, Department of Archaeology and History, La Trobe University, Bundoora, Victoria, Australia
| | - A B Leece
- Palaeoanthropology Lab, Department of Archaeology and History, La Trobe University, Bundoora, Victoria, Australia
- Geoarchaeology and Archaeometry Research Group, Southern Cross Geoscience, Southern Cross University, Lismore, New South Wales, Australia
| | - Stephanie E Baker
- Palaeo-Research Institute, University of Johannesburg, Gauteng, South Africa
| | - Andy I R Herries
- Palaeoanthropology Lab, Department of Archaeology and History, La Trobe University, Bundoora, Victoria, Australia
- Palaeo-Research Institute, University of Johannesburg, Gauteng, South Africa
| | - David S Strait
- Palaeo-Research Institute, University of Johannesburg, Gauteng, South Africa
- Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri, USA
- DFG Center for Advanced Studies "Words, Bones, Genes, Tools", University of Tübingen, Tübingen, Germany
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3
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Braga J, Grine FE. New craniodental fossils of Paranthropus robustus from Kromdraai, South Africa (2014-2017 excavations). J Hum Evol 2024; 188:103481. [PMID: 38382132 DOI: 10.1016/j.jhevol.2023.103481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 11/21/2023] [Accepted: 12/02/2023] [Indexed: 02/23/2024]
Abstract
Since the initial discovery of Paranthropus robustus at the site of Kromdraai in 1938, the hypodigm of this species has been expanded by subsequent work at the localities of Swartkrans and Drimolen, with a few fossils also known from Cooper's D, Gondolin and Sterkfontein Member 5. Beginning in 2014, systematic excavations at Kromdraai uncovered a large and previously unknown fossiliferous area, shedding light on Units O and P in the earliest part of the site's stratigraphic sequence. The aim of this paper is to provide detailed descriptions and illustrations of 30 P. robustus craniodental specimens recovered between 2014 and 2017 within the Unit P deposits at Kromdraai. This new sample predates all prior conspecific specimens found at this site (including the holotype of P. robustus from Kromdraai, TM 1517). Its basic dental morphology dimensions and cranial features are compared in a preliminary analysis with other P. robustus samples. The P. robustus sample from Kromdraai Unit P documents previously unknown portions of the P. robustus juvenile cranium. The new dental and cranial remains aid in the exploration of potential morphological distinctions between site-specific P. robustus samples and are compared favorably in size and morphology with the small P. robustus specimens from Drimolen (e.g., DNH 7). These findings do not support the hypothesis that the specimens from Drimolen belong to a different taxonomic group. Instead, they reinforce the presence of a significant degree of sexual dimorphism within P. robustus. The Kromdraai Unit P specimens also contribute to the biodemographic profile of P. robustus. The notable prevalence of infants (i.e., juvenile individuals before the emergence of their first permanent molars) mirrors the natural mortality profiles observed in wild chimpanzees. This suggests a closer resemblance in the processes of accumulation in Kromdraai Unit P and Drimolen than at Swartkrans.
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Affiliation(s)
- José Braga
- Centre for Anthropobiology & Genomics of Toulouse, CNRS UMR 5288, Université de Toulouse, Université Paul Sabatier, 37 allées Jules Guesde, Toulouse, France; Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa.
| | - Frederick E Grine
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA; Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794, USA
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4
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Strait DS, Martin JM, Leece AB, Baker SE, Herries AIR. Reply to Rak et al. (2021) "The DNH 7 skull of Australopithecus robustus from Drimolen (Main Quarry), South Africa" [J. Hum. Evol. 151 (2021), 102913]. J Hum Evol 2023; 181:103403. [PMID: 37354648 DOI: 10.1016/j.jhevol.2023.103403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 05/28/2023] [Accepted: 05/28/2023] [Indexed: 06/26/2023]
Affiliation(s)
- David S Strait
- Department of Anthropology, Washington University in St. Louis, One Brookings Ave., St. Louis, MO 63130, USA; Palaeo-Research Institute, University of Johannesburg, House 10, Bunting Road Campus, Auckland Park, Gauteng 2092, South Africa.
| | - Jesse M Martin
- Palaeoscience, Dept. of Archaeology and History, La Trobe University, Melbourne Campus, Corner of Plenty Road and Kingsbury Drive, Bundoora, 3086 VIC, Australia
| | - A B Leece
- Palaeoscience, Dept. of Archaeology and History, La Trobe University, Melbourne Campus, Corner of Plenty Road and Kingsbury Drive, Bundoora, 3086 VIC, Australia; Geoarchaeology and Archaeometry Research Group, Faculty of Science and Engineering, Southern Cross University, Military Rd, East Lismore, NSW 2480, Australia
| | - Stephanie E Baker
- Palaeo-Research Institute, University of Johannesburg, House 10, Bunting Road Campus, Auckland Park, Gauteng 2092, South Africa
| | - Andy I R Herries
- Palaeo-Research Institute, University of Johannesburg, House 10, Bunting Road Campus, Auckland Park, Gauteng 2092, South Africa; Palaeoscience, Dept. of Archaeology and History, La Trobe University, Melbourne Campus, Corner of Plenty Road and Kingsbury Drive, Bundoora, 3086 VIC, Australia
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5
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Delezene LK, Skinner MM, Bailey SE, Brophy JK, Elliott MC, Gurtov A, Irish JD, Moggi-Cecchi J, de Ruiter DJ, Hawks J, Berger LR. Descriptive catalog of Homo naledi dental remains from the 2013 to 2015 excavations of the Dinaledi Chamber, site U.W. 101, within the Rising Star cave system, South Africa. J Hum Evol 2023; 180:103372. [PMID: 37229947 DOI: 10.1016/j.jhevol.2023.103372] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 03/31/2023] [Accepted: 03/31/2023] [Indexed: 05/27/2023]
Abstract
More than 150 hominin teeth, dated to ∼330-241 thousand years ago, were recovered during the 2013-2015 excavations of the Dinaledi Chamber of the Rising Star cave system, South Africa. These fossils comprise the first large single-site sample of hominin teeth from the Middle Pleistocene of Africa. Though scattered remains attributable to Homo sapiens, or their possible lineal ancestors, are known from older and younger sites across the continent, the distinctive morphological feature set of the Dinaledi teeth supports the recognition of a novel hominin species, Homo naledi. This material provides evidence of African Homo lineage diversity that lasts until at least the Middle Pleistocene. Here, a catalog, anatomical descriptions, and details of preservation and taphonomic alteration are provided for the Dinaledi teeth. Where possible, provisional associations among teeth are also proposed. To facilitate future research, we also provide access to a catalog of surface files of the Rising Star jaws and teeth.
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Affiliation(s)
- Lucas K Delezene
- Department of Anthropology, University of Arkansas, Fayetteville, AR 72701, USA; Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa.
| | - Matthew M Skinner
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa; School of Anthropology and Conservation, University of Kent, Marlowe Building, Canterbury CT2 7NR, UK; Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Shara E Bailey
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany; Department of Anthropology, Center for the Study of Human Origins, New York University, New York, NY 10003, USA
| | - Juliet K Brophy
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa; Department of Geography and Anthropology, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Marina C Elliott
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa; Department of Archaeology, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, USA
| | - Alia Gurtov
- Stripe, Inc., 199 Water Street, 30th Floor, New York, NY 10038, USA
| | - Joel D Irish
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa; School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK
| | - Jacopo Moggi-Cecchi
- Laboratory of Anthropology, Department of Biology, University of Florence, Via del Proconsolo 12, Firenze 50122, Italy
| | - Darryl J de Ruiter
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa; Department of Anthropology, Texas A&M University, College Station, TX 77843, USA
| | - John Hawks
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa; Department of Anthropology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Lee R Berger
- National Geographic Society, 1145 17th Street NW, Washington, DC 20036, USA; Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Private Bag 3, WITS 2050, South Africa
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6
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Braga J, Wood BA, Zimmer VA, Moreno B, Miller C, Thackeray JF, Zipfel B, Grine FE. Hominin fossils from Kromdraai and Drimolen inform Paranthropus robustus craniofacial ontogeny. SCIENCE ADVANCES 2023; 9:eade7165. [PMID: 37134165 PMCID: PMC10156105 DOI: 10.1126/sciadv.ade7165] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Ontogeny provides critical information about the evolutionary history of early hominin adult morphology. We describe fossils from the southern African sites of Kromdraai and Drimolen that provide insights into early craniofacial development in the Pleistocene robust australopith Paranthropus robustus. We show that while most distinctive robust craniofacial features appear relatively late in ontogeny, a few do not. We also find unexpected evidence of independence in the growth of the premaxillary and maxillary regions. Differential growth results in a proportionately larger and more postero-inferiorly rotated cerebral fossa in P. robustus infants than in the developmentally older Australopithecus africanus juvenile from Taung. The accumulated evidence from these fossils suggests that the iconic SK 54 juvenile calvaria is more likely early Homo than Paranthropus. It is also consistent with the hypothesis that P. robustus is more closely related to Homo than to A. africanus.
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Affiliation(s)
- José Braga
- Centre for Anthropobiology and Genomics of Toulouse, CNRS UMR 5288, Université de Toulouse, Université Paul Sabatier, 37 allées Jules Guesde, Toulouse, France
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg, South Africa
| | - Bernard A Wood
- Center for the Advanced Study of Human Paleobiology, George Washington University, Washington, DC 20052, USA
| | | | - Benjamin Moreno
- SARL IMA Solutions, 19 rue Jean Mermoz, 31100 Toulouse, France
| | - Catherine Miller
- Department of Anthropology, Dartmouth College, Hanover, NH 03755, USA
| | - John F Thackeray
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg, South Africa
| | - Bernhard Zipfel
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, WITS 2050, Johannesburg, South Africa
| | - Frederick E Grine
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA
- Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794, USA
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7
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Mongle CS, Strait DS, Grine FE. An updated analysis of hominin phylogeny with an emphasis on re-evaluating the phylogenetic relationships of Australopithecus sediba. J Hum Evol 2023; 175:103311. [PMID: 36706599 DOI: 10.1016/j.jhevol.2022.103311] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 12/16/2022] [Accepted: 12/16/2022] [Indexed: 01/26/2023]
Abstract
The discovery and description of Australopithecus sediba has reignited the debate over the evolutionary history of the australopiths and the genus Homo. It has been suggested that A. sediba may be an ancestor of Homo because it possesses a mosaic of derived Homo-like and primitive australopith-like traits. However, an alternative hypothesis proposes that the majority of the purported Homo-like craniodental characters can be attributed to the juvenile status of the type specimen, MH1. We conducted an independent character assessment of the craniodental morphology of A. sediba, with particular emphasis on evaluating whether the ontogenetic status of MH1 may have affected its purported Homo-like characteristics. In doing so, we have also expanded fossil hypodigms to incorporate the new Australopithecus anamensis cranium from Woranso-Mille (MRD-VP-1/1), as well as recently described Paranthropus robustus cranial remains from Drimolen (DNH 7, DNH 155). Morphological character data were analyzed using both standard parsimony and Bayesian techniques. In addition, we conducted a series of Bayesian analyses constrained to evaluate the hypothesis that Australopithecus africanus and A. sediba are sister taxa. Based on the results of the parsimony and Bayesian analyses, we could not reject the hypothesis that A. sediba shares its closest phylogenetic affinities with the genus Homo. Therefore, based on currently available craniodental evidence, we conclude that A. sediba is plausibly the terminal end of a lineage that shared a common ancestor with the earliest representatives of Homo. We caution, however, that the discovery of new A. sediba fossils preserving adult cranial morphology or the inclusion of postcranial characters may ultimately necessitate a re-evaluation of this hypothesis.
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Affiliation(s)
- Carrie S Mongle
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794-4364, USA; Division of Anthropology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024-5192, USA; Turkana Basin Institute, Stony Brook University, Stony Brook, NY 11794-4364, USA.
| | - David S Strait
- Department of Anthropology, Washington University in St. Louis, 1 Brookings Dr, St. Louis, MO 63130, USA; Palaeo-Research Institute, University of Johannesburg, Cottesloe, Johannesburg, 2092, South Africa
| | - Frederick E Grine
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794-4364, USA; Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794-4364, USA
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8
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Leece AB, Martin JM, Baker S, Wilson C, Strait DS, Schwartz GT, Herries AIR. New hominin dental remains from the ∼2.04-1.95 Ma Drimolen Main Quarry, South Africa. Ann Hum Biol 2023; 50:407-427. [PMID: 37812213 DOI: 10.1080/03014460.2023.2261849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023]
Abstract
BACKGROUND The Drimolen Palaeocave site is situated within the UNESCO Fossil Hominid Sites of South Africa World Heritage Area and has yielded numerous hominin fossils since its discovery in 1992. Most of these fossils are represented by isolated dental elements, which have been attributed to either of two distinct hominin genera, Paranthropus and Homo. AIM This paper provides morphological descriptions for a further 19 specimens that have been recovered from the ∼2.04-1.95 Ma Drimolen Main Quarry (DMQ) deposits since 2008. This paper also discusses the two primary hypotheses used to explain Paranthropus robustus variation: sexual dimorphism, and micro-evolution within a lineage. SUBJECTS AND METHODS These 19 fossils are represented by 47 dental elements and expand the sample of DMQ early Homo from 13 to 15, and the sample of Paranthropus robustus from 69 to 84. RESULTS The evidence presented in this paper was found to be inconsistent with the sexual dimorphism hypothesis. CONCLUSION Some support was found for the micro-evolution hypothesis.
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Affiliation(s)
- A B Leece
- Palaeoscience, Department of Archaeology and History, La Trobe University, Bundoora, VIC, Australia
- Geoarchaeology and Archaeometry Research Group, Southern Cross GeoScience, Southern Cross University, Lismore, NSW, Australia
| | - J M Martin
- Palaeoscience, Department of Archaeology and History, La Trobe University, Bundoora, VIC, Australia
| | - S Baker
- Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa
| | - C Wilson
- Palaeoscience, Department of Archaeology and History, La Trobe University, Bundoora, VIC, Australia
| | - D S Strait
- Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa
- Department of Anthropology, WA University in St. Louis, St. Louis, MO, USA
| | - G T Schwartz
- Institute of Human Origins, School of Human Evolution and Social Change, AZ State University, Tempe, AZ, USA
| | - A I R Herries
- Palaeoscience, Department of Archaeology and History, La Trobe University, Bundoora, VIC, Australia
- Palaeo-Research Institute, University of Johannesburg, Johannesburg, South Africa
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9
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Leece AB, Martin JM, Herries AIR, Riga A, Menter CG, Moggi‐Cecchi J. New hominin dental remains from the Drimolen Main Quarry, South Africa (1999–2008). AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 179:240-260. [PMCID: PMC9796117 DOI: 10.1002/ajpa.24570] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 04/20/2022] [Accepted: 05/17/2022] [Indexed: 10/10/2023]
Abstract
Objectives Twenty‐four dental specimens from the Drimolen Main Quarry (DMQ) are described. This increases the number of DMQ Paranthropus robustus specimens from 48 to 63 and DMQ Homo specimens from 8 to 12. This allows reassessment of the proposed differences between the DMQ P. robustus assemblage and that of Swartkrans. Analysis conducted assesses intraspecific and inter‐locality variation. Materials and Methods We examined the P. robustus and early Homo assemblages from South Africa. Morphology was observed using a hand lens and a binocular microscope. Mesiodistal and buccolingual measurements were taken using plastic‐tipped calipers. Summary statistics were generated and patterns of variability in P. robustus were assessed through box plots and Mann–Whitney U tests. Results Comparison between the expanded DMQ and Swartkrans P. robustus assemblages demonstrates overlap in size. Ten dental variables show statistically significant differences. Discussion The expanded P. robustus sample allowed us to re‐examine previous analyses of differences in tooth size between the samples. While analyses presented here show a high degree of overlap in the MD and BL dimensions of the two assemblages, significant differences were found in the mean values of these variables in the postcanine maxillary teeth—consistent with previous analyses. Two current hypotheses may explain this pattern: 1) dental size increase through the P. robustus lineage or 2) different sample composition between the two sites. Small sample sizes for all permanent dental classes in the DMQ assemblage represents a limitation on this analysis and interpretations thereof. Any addition to the DMQ or the Swartkrans samples may alter these results.
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Affiliation(s)
- Angeline B. Leece
- Palaeoscience Labs, Department of Archaeology and HistoryLa Trobe University, Melbourne CampusBundooraVictoriaAustralia
| | - Jesse M. Martin
- Palaeoscience Labs, Department of Archaeology and HistoryLa Trobe University, Melbourne CampusBundooraVictoriaAustralia
| | - Andy I. R. Herries
- Palaeoscience Labs, Department of Archaeology and HistoryLa Trobe University, Melbourne CampusBundooraVictoriaAustralia
- Palaeo Research Institute, Humanities Research VillageUniversity of JohannesburgAuckland ParkSouth Africa
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10
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New fossils from Kromdraai and Drimolen, South Africa, and their distinctiveness among Paranthropus robustus. Sci Rep 2022; 12:13956. [PMID: 35977986 PMCID: PMC9385619 DOI: 10.1038/s41598-022-18223-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/08/2022] [Indexed: 11/08/2022] Open
Abstract
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 emphasize the importance of allometry to interpret paleodiversity in P. robustus as either the consequence of differences in body size, or as yet unknown factors. Some features of the inner ear of P. robustus represent directional selection soon after its origin, whereas the size and shape variations described here may result from evolutionary changes.
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11
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Abstract
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 of 23 specimens, only 4 are unambiguously attributed to Homo, 3 of them coming from Swartkrans member 1 (SK 27, SK 847, and SKX 21204) and 1 from Sterkfontein (Sts 9). Three other specimens from Sterkfontein (StW 80 and 81, SE 1508, and StW 669) approximate the Homo condition in terms of overall enamel-dentine junction shape, but retain Australopithecus-like dental traits, and their generic status remains unclear. The other specimens, including SK 15, present a dominant australopith dental signature. In light of these results, previous dietary and ecological interpretations can be reevaluated, showing that the geochemical signal of one tooth from Kromdraai (KB 5223) and two from Swartkrans (SK 96 and SKX 268) is consistent with that of australopiths.
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12
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Braga J, Samir C, Fradi A, Feunteun Y, Jakata K, Zimmer VA, Zipfel B, Thackeray JF, Macé M, Wood BA, Grine FE. Cochlear shape distinguishes southern African early hominin taxa with unique auditory ecologies. Sci Rep 2021; 11:17018. [PMID: 34426640 PMCID: PMC8382707 DOI: 10.1038/s41598-021-96543-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/11/2021] [Indexed: 02/07/2023] Open
Abstract
Insights into potential differences among the bony labyrinths of Plio-Pleistocene hominins may inform their evolutionary histories and sensory ecologies. We use four recently-discovered bony labyrinths from the site of Kromdraai to significantly expand the sample for Paranthropus robustus. Diffeomorphometry, which provides detailed information about cochlear shape, reveals size-independent differences in cochlear shape between P. robustus and Australopithecus africanus that exceed those among modern humans and the African apes. The cochlea of P. robustus is distinctive and relatively invariant, whereas cochlear shape in A. africanus is more variable, resembles that of early Homo, and shows a degree of morphological polymorphism comparable to that evinced by modern species. The curvature of the P. robustus cochlea is uniquely derived and is consistent with enhanced sensitivity to low-frequency sounds. Combined with evidence for selection, our findings suggest that sound perception shaped distinct ecological adaptations among southern African early hominins.
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Affiliation(s)
- J. Braga
- grid.15781.3a0000 0001 0723 035XCentre d’Anthropobiologie et de Génomique de Toulouse, Université Paul Sabatier Toulouse III, Faculté de Médecine Purpan, 37 allées Jules Guesde, Toulouse, France ,grid.11951.3d0000 0004 1937 1135Evolutionary Studies Institute, University of the Witwatersrand, PO WITS, Johannesburg, 2050 South Africa
| | - C. Samir
- grid.503317.30000 0000 9971 4898LIMOS, UMR 6158 CNRS-Université Clermont Auvergne, 63173 Aubière, France
| | - A. Fradi
- grid.503317.30000 0000 9971 4898LIMOS, UMR 6158 CNRS-Université Clermont Auvergne, 63173 Aubière, France
| | - Y. Feunteun
- grid.503317.30000 0000 9971 4898LIMOS, UMR 6158 CNRS-Université Clermont Auvergne, 63173 Aubière, France
| | - K. Jakata
- grid.11951.3d0000 0004 1937 1135Evolutionary Studies Institute, University of the Witwatersrand, PO WITS, Johannesburg, 2050 South Africa
| | - V. A. Zimmer
- grid.6936.a0000000123222966Faculty of Informatics, Technical University of Munich, Munich, Germany
| | - B. Zipfel
- grid.11951.3d0000 0004 1937 1135Evolutionary Studies Institute, University of the Witwatersrand, PO WITS, Johannesburg, 2050 South Africa
| | - J. F. Thackeray
- grid.11951.3d0000 0004 1937 1135Evolutionary Studies Institute, University of the Witwatersrand, PO WITS, Johannesburg, 2050 South Africa
| | - M. Macé
- Véto 31, 73 Avenue du Général de Gaulle, 47000 Agen, France
| | - B. A. Wood
- grid.253615.60000 0004 1936 9510Center for the Advanced Study of Human Paleobiology, George Washington University, Washington, DC 20052 USA
| | - F. E. Grine
- grid.36425.360000 0001 2216 9681Department of Anthropology, Stony Brook University, Stony Brook, NY 11794 USA ,grid.36425.360000 0001 2216 9681Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY 11794 USA
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