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Brasil MF, Monson TA, Taylor CE, Yohler RM, Hlusko LJ. A Pleistocene assemblage of near-modern Papio hamadryas from the Middle Awash study area, Afar Rift, Ethiopia. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2023; 180:48-76. [PMID: 36790648 DOI: 10.1002/ajpa.24634] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 07/15/2022] [Accepted: 09/05/2022] [Indexed: 11/13/2022]
Abstract
OBJECTIVES The aim of this study is to assess a new assemblage of papionin fossils (n = 143) recovered from later Pleistocene sediments in the Middle Awash study area in the Afar Rift of Ethiopia. MATERIALS AND METHODS We collected metric and qualitative data to compare the craniodental and postcranial anatomy of the papionin fossils with subspecies of modern Papio hamadryas and with Plio-Pleistocene African papionins. We also estimated sex and ontogenetic age. RESULTS The new fossils fit well within the range of morphological variation observed for extant P. hamadryas, overlapping most closely in dental size and proportions with the P. h. cynocephalus individuals in our extant samples, and well within the ranges of P. h. anubis and P. h. hamadryas. The considerable overlap in craniodental anatomy with multiple subspecies precludes subspecific diagnosis. We therefore referred 143 individuals to P. hamadryas ssp. The majority of the individuals assessed for ontogenetic age fell into middle- and old-adult age categories based on the degree of dental wear. Males (26%) were better represented than females (12%) among individuals preserving the canine-premolar honing complex. DISCUSSION These new near-modern P. hamadryas fossils provide a window into population-level variation in the later Pleistocene. Our findings echo previous suggestions from genomic studies that the papionin family tree may have included a ghost population and provide a basis for future testing of hypotheses regarding hybridization in the recent evolutionary history of this taxon.
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Affiliation(s)
- Marianne F Brasil
- Berkeley Geochronology Center, Berkeley, California, USA.,Human Evolution Research Center, University of California Berkeley, Berkeley, California, USA
| | - Tesla A Monson
- Department of Anthropology, Western Washington University, Bellingham, Washington, USA
| | - Catherine E Taylor
- Human Evolution Research Center, University of California Berkeley, Berkeley, California, USA.,Department of Integrative Biology, University of California Berkeley, Berkeley, California, USA
| | - Ryan M Yohler
- Human Evolution Research Center, University of California Berkeley, Berkeley, California, USA.,Department of Integrative Biology, University of California Berkeley, Berkeley, California, USA
| | - Leslea J Hlusko
- Human Evolution Research Center, University of California Berkeley, Berkeley, California, USA.,Department of Integrative Biology, University of California Berkeley, Berkeley, California, USA.,Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain
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Arenson JL, Harrison T, Sargis EJ, Taboada HG, Gilbert CC. A new species of fossil guenon (Cercopithecini, Cercopithecidae) from the Early Pleistocene Lower Ngaloba Beds, Laetoli, Tanzania. J Hum Evol 2022; 163:103136. [PMID: 35033736 DOI: 10.1016/j.jhevol.2021.103136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/06/2021] [Accepted: 12/06/2021] [Indexed: 11/30/2022]
Abstract
The living guenons (Cercopithecini, Cercopithecidae) are speciose and widely distributed across sub-Saharan Africa but are poorly represented in the fossil record. In addition, the craniodental and skeletal similarity of the guenons has hampered the identification of fragmentary material, likely obscuring the taxonomic diversity represented in the fossil record. Here, we describe a new fossil guenon specimen (LAET 75-3703) from the Lower Ngaloba Beds, Laetoli in Tanzania, dated to ∼1.7-1.2 Ma and preserving the lower face and mandible. Comparison to 278 extant guenon specimens, representing all six extant genera, identified several informative traits for distinguishing between the morphologically similar Chlorocebus and Cercopithecus, and these support the attribution of LAET 75-3703 to Chlorocebus. A discriminant function analysis of seven craniodental indices on a subsample of Chlorocebus and Cercopithecus was robust with an overall correct classification rate of 80.4%, and it classified LAET 75-3703 as a member of Chlorocebus with a posterior probability of 92.7%. LAET 75-3703 shares with Chlorocebus the presence of small 'thumbprint' depressions on the maxilla; a tall, narrow, and diamond-shaped nasal aperture; a relatively longer and shallower face; relatively buccolingually broader molars; and a shallow mandible that decreases in depth posteriorly. In addition, LAET 75-3703 is distinguished from all extant guenons, including other species of Chlorocebus, in having a very small P3 relative to M1 area. As such, LAET 75-3703 is assigned to a new species, Chlorocebus ngedere sp. nov. This specimen represents the first cercopithecin from Laetoli, as well as the oldest fossil cercopithecin confidently attributed to a modern genus.
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Affiliation(s)
- Julia L Arenson
- PhD Program in Anthropology, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY, 10016, USA; New York Consortium in Evolutionary Primatology (NYCEP), New York, NY, 10016, USA.
| | - Terry Harrison
- New York Consortium in Evolutionary Primatology (NYCEP), New York, NY, 10016, USA; Center for the Study of Human Origins, Department of Anthropology, New York University, 25 Waverly Place, New York, NY, 10003, USA
| | - Eric J Sargis
- Department of Anthropology, Yale University, 10 Sachem Street, New Haven, CT, 06511, USA; Divisions of Vertebrate Paleontology and Vertebrate Zoology, Yale Peabody Museum of Natural History, 170 Whitney Avenue, New Haven, CT, 06511, USA; Yale Institute for Biospheric Studies, P.O. Box 208118, New Haven, CT, 06520, USA
| | - Hannah G Taboada
- Center for the Study of Human Origins, Department of Anthropology, New York University, 25 Waverly Place, New York, NY, 10003, USA
| | - Christopher C Gilbert
- PhD Program in Anthropology, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY, 10016, USA; New York Consortium in Evolutionary Primatology (NYCEP), New York, NY, 10016, USA; Department of Anthropology, Hunter College, CUNY, 695 Park Avenue, New York, NY, 10065, USA; Division of Paleontology, American Museum of Natural History, Central Park West, New York, NY, 10024, USA
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