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Russo GA, Prang TC, McGechie FR, Kuo S, Ward CV, Feibel C, Nengo IO. An ape partial postcranial skeleton (KNM-NP 64631) from the Middle Miocene of Napudet, northern Kenya. J Hum Evol 2024; 192:103519. [PMID: 38843697 DOI: 10.1016/j.jhevol.2024.103519] [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: 10/06/2023] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 06/23/2024]
Abstract
An ape partial postcranial skeleton (KNM-NP 64631) was recovered during the 2015-2021 field seasons at Napudet, a Middle Miocene (∼13 Ma) locality in northern Kenya. Bony elements representing the shoulder, elbow, hip, and ankle joints, thoracic and lumbar vertebral column, and hands and feet, offer valuable new information about the body plan and positional behaviors of Middle Miocene apes. Body mass estimates from femoral head dimensions suggest that the KNM-NP 64631 individual was smaller-bodied (c. 13-17 kg) than some Miocene taxa from eastern Africa, including Ekembo nyanzae, and probably Equatorius africanus or Kenyapithecus wickeri, and was more comparable to smaller-bodied male Nacholapithecus kerioi individuals. Similar to many Miocene apes, the KNM-NP 64631 individual had hip and hallucal tarsometatarsal joints reflecting habitual hindlimb loading in a variety of postures, a distal tibia with a large medial malleolus, an inflated humeral capitulum, probably a long lumbar spine, and a long pollical proximal phalanx relative to femoral head dimensions. The KNM-NP 64631 individual departs from most Early Miocene apes in its possession of a more steeply beveled radial head and deeper humeral zona conoidea, reflecting enhanced supinating-pronating abilities at the humeroradial joint. The KNM-NP 64631 individual also differs from Early Miocene Ekembo heseloni in having a larger elbow joint (inferred from radial head size) relative to the mediolateral width of the lumbar vertebral bodies and a more asymmetrical talar trochlea, and in these ways recalls inferred joint proportions for, and talocrural morphology of, N. kerioi. Compared to most Early Miocene apes, the KNM-NP 64631 individual likely relied on more forelimb-dominated arboreal behaviors, perhaps including vertical climbing (e.g., extended elbow, hoisting). Moreover, the Napudet ape partial postcranial skeleton suggests that an arboreally adapted body plan characterized by relatively large (here, based on joint size) forelimbs, but lacking orthograde suspensory adaptations, may not have been 'unusual' among Middle Miocene apes.
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Affiliation(s)
- Gabrielle A Russo
- Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Thomas C Prang
- Department of Anthropology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Faye R McGechie
- Department of Basic Medical Sciences, University of Arizona College of Medicine - Phoenix 475 N 5th St, Phoenix, AZ 85004, USA
| | - Sharon Kuo
- Department of Biomedical Sciences, University of Minnesota, Duluth, Duluth, MN 55802, USA; Technological Primates Research Group, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Carol V Ward
- Department of Pathology and Anatomical Sciences, M263 Medical Sciences Building, University of Missouri, Columbia, MO 65212, USA; Department of Anthropology, 107 Swallow Hall, University of Missouri, Columbia, MO 65211, USA
| | - Craig Feibel
- Department of Earth and Planetary Sciences, Rutgers University, Busch Campus, Piscataway, NJ 08854, USA; Department of Anthropology, Rutgers University, Douglass Campus, New Brunswick, NJ 08901, USA
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Selig KR. Hypoconulid loss in cercopithecins: Functional and developmental considerations. J Hum Evol 2024; 187:103479. [PMID: 38181576 DOI: 10.1016/j.jhevol.2023.103479] [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: 05/29/2023] [Revised: 11/28/2023] [Accepted: 11/28/2023] [Indexed: 01/07/2024]
Abstract
Cercopithecins differ from papionins in lacking a M3 hypoconulid. Although this loss may be related to dietary differences, the functional and developmental ramifications of hypoconulid loss are currently unclear. The following makes use of dental topographic analysis to quantify shape variation in a sample of cercopithecin M3s, as well as in a sample of Macaca, which has a hypoconulid. To help understand the consequences of hypoconulid loss, Macaca M3s were virtually cropped to remove the hypoconulid and were also subjected to dental topographic analysis. The patterning cascade model and the inhibitory cascade model attempt to explain variation in cusp pattern and molar proportions, respectively. These models have both previously been used to explain patterns of variation in cercopithecines, but have not been examined in the context of hypoconulid loss. For example, previous work suggests that earlier developing cusps impact the development of later developing cusps (i.e., the hypoconulid) and that cercopithecines do not conform to the predictions of the inhibitory cascade model in that the size of the molars is not linear moving distally. Results of the current study suggest that the loss of the hypoconulid is associated with a reduction in dental topography among cercopithecins, which is potentially related to diet, although the connection to diet is not necessarily clear. Results also suggest that the loss of the hypoconulid can be explained by the patterning cascade model, and that hypoconulid loss explains the apparent lack of support for the inhibitory cascade model among cercopithecines. These findings highlight the importance of a holistic approach to studying variation in molar proportions and developmental models.
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Affiliation(s)
- Keegan R Selig
- Department of Evolutionary Anthropology, Duke University, Biological Sciences Building, 130 Science Drive, Durham, NC, 27708, USA.
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Morse PE, Pampush JD, Kay RF. Dental topography of the Oligocene anthropoids Aegyptopithecus zeuxis and Apidium phiomense: Paleodietary insights from analysis of wear series. J Hum Evol 2023; 180:103387. [PMID: 37245335 DOI: 10.1016/j.jhevol.2023.103387] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/30/2023]
Abstract
Fossil primate dietary inference is enhanced when ascertained through multiple, distinct proxies. Dental topography can be used to assess changes in occlusal morphology with macrowear, providing insight on tooth use and function across the lifespans of individuals. We measured convex Dirichlet normal energy-a dental topography metric reflecting occlusal sharpness of features such as cusps and crests-in macrowear series of the second mandibular molars of two African anthropoid taxa from ∼30 Ma (Aegyptopithecus zeuxis and Apidium phiomense). Wear was quantified via three proxies: occlusal dentine exposure, inverse relief index, and inverse occlusal relief. The same measurements were calculated on macrowear series of four extant platyrrhine taxa (Alouatta, Ateles, Plecturocebus, and Sapajus apella) to provide an analogical framework for dietary inference in the fossil taxa. We predicted that Ae. zeuxis and Ap. phiomense would show similar patterns in topographic change with wear to one another and to extant platyrrhine frugivores like Ateles and Plecturocebus. The fossil taxa have similar distributions of convex Dirichlet normal energy to one another, and high amounts of concave Dirichlet normal energy 'noise' in unworn molars-a pattern shared with extant hominids that may distort dietary interpretations. Inverse relief index was the most useful wear proxy for comparison among the taxa in this study which possess disparate enamel thicknesses. Contrary to expectations, Ae. zeuxis and Ap. phiomense both resemble S. apella in exhibiting an initial decline in convex Dirichlet normal energy followed by an increase at the latest stages of wear as measured by inverse relief index, lending support to previous suggestions that hard-object feeding played a role in their dietary ecology. Based on these results and previous analyses of molar shearing quotients, microwear, and enamel microstructure, we suggest that Ae. zeuxis had a pitheciine-like strategy of seed predation, whereas Ap. phiomense potentially consumed berry-like compound fruits with hard seeds.
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Affiliation(s)
- Paul E Morse
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.
| | - James D Pampush
- Department of Exercise Science, High Point University, High Point, NC 27260, USA; Department of Physician Assistant Studies, High Point University, High Point, NC 27260, USA
| | - Richard F Kay
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA; Division of Earth and Climate Sciences, Nicholas School, Duke University, Durham, NC 27708, USA
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Guatelli-Steinberg D, Schwartz GT, O'Hara MC, Gurian K, Rychel J, Dunham N, Cunneyworth PMK, Donaldson A, McGraw WS. Aspects of molar form and dietary proclivities of African colobines. J Hum Evol 2023; 180:103384. [PMID: 37201412 DOI: 10.1016/j.jhevol.2023.103384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 04/04/2023] [Accepted: 04/09/2023] [Indexed: 05/20/2023]
Abstract
This study investigates aspects of molar form in three African colobine species: Colobus polykomos, Colobus angolensis, and Piliocolobus badius. Our samples of C. polykomos and P. badius are from the Taï Forest, Ivory Coast; our sample of C. angolensis is from Diani, Kenya. To the extent that protective layers surrounding seeds are hard, we predicted that molar features related to hard-object feeding would be more pronounced in Colobus than they are Piliocolobus, as seed-eating generally occurs at higher frequencies in species of the former. We further predicted that among the colobines we studied, these features would be most pronounced in Taï Forest C. polykomos, which feeds on Pentaclethra macrophylla seeds encased within hard and tough seed pods. We compared overall enamel thickness, enamel thickness distribution, absolute crown strength, cusp tip geometry, and flare among molar samples. Sample sizes per species and molar type varied per comparison. We predicted differences in all variables except overall enamel thickness, which we expected would be invariant among colobines as a result of selection for thin enamel in these folivorous species. Of the variables we examined, only molar flare differed significantly between Colobus and Piliocolobus. Our findings suggest that molar flare, an ancient feature of cercopithecoid molars, was retained in Colobus but not in Piliocolobus, perhaps as a result of differences in the seed-eating proclivities of the two genera. Contrary to predictions, none of the aspects of molar form we investigated tracked current dietary differences in seed-eating between the two Colobus species. Finally, we explored the possibility that molar flare and absolute crown strength, when analyzed together, might afford greater differentiation among these colobine species. A multivariate t test of molar flare and absolute crown strength differentiated C. polykomos and P. badius, possibly reflecting known niche divergence between these two sympatric Taï Forest species.
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Affiliation(s)
- Debbie Guatelli-Steinberg
- Department of Anthropology, The Ohio State University, 174 West 18th Ave, Columbus, OH, 43210, USA; School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK.
| | - Gary T Schwartz
- Institute of Human Origins & School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, 85287, USA
| | - Mackie C O'Hara
- Department of Anthropology, The Ohio State University, 174 West 18th Ave, Columbus, OH, 43210, USA; School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK
| | - Kaita Gurian
- Department of Anthropology, The Ohio State University, 174 West 18th Ave, Columbus, OH, 43210, USA
| | - Jess Rychel
- Department of Anthropology, The Ohio State University, 174 West 18th Ave, Columbus, OH, 43210, USA
| | - Noah Dunham
- Division of Conservation and Science, Cleveland Metroparks Zoo, 4200 Wildlife Way, Cleveland, OH, 44109, USA; Department of Biology, Case Western Reserve University, 2080 Adelbert Road, Cleveland, OH, 44106, USA
| | | | - Andrea Donaldson
- Colobus Conservation, P.O. Box 5380-80401, Diani, Kenya; Department of Anthropology, Durham University, Durham, DH1 3LE, UK
| | - W Scott McGraw
- Department of Anthropology, The Ohio State University, 174 West 18th Ave, Columbus, OH, 43210, USA
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Guatelli‐Steinberg D, Schwartz GT, O'Hara MC, Gurian K, Rychel J, McGraw WS. Molar form, enamel growth, and durophagy in Cercocebus and Lophocebus. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 179:386-404. [PMCID: PMC9796247 DOI: 10.1002/ajpa.24592] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 06/20/2022] [Accepted: 06/29/2022] [Indexed: 05/29/2023]
Abstract
Objectives To test the hypothesis that differences in crown structure, enamel growth, and crown geometry in Cercocebus and Lophocebus molars covary with differences in the feeding strategies (habitual vs. fallback durophagy, respectively) of these two genera. Relative to Lophocebus molars, Cercocebus molars are predicted to possess features associated with greater fracture resistance and to differ in enamel growth parameters related to these features. Materials and Methods Sample proveniences are as follows: Cercocebus atys molars are from the Taï Forest, Ivory Coast; Lophocebus albigena molars are from a site north of Makoua, Republic of Congo; and a Lophocebus atterimus molar is from the Lomako Forest, Democratic Republic of Congo. For μCT scans on which aspects of molar form were measured, sample sizes ranged from 5 to 35 for Cercocebus and 3 to 12 for Lophocebus. A subsample of upper molars was physically sectioned to measure enamel growth variables. Results Partly as a function of their larger size, Cercocebus molars had significantly greater absolute crown strength (ACS) than Lophocebus molars, supporting the hypothesis. Greater crown heights in Cercocebus are achieved through faster enamel extension rates. Also supporting the hypothesis, molar flare and proportional occlusal basin enamel thickness were significantly greater in Cercocebus. Relative enamel thickness (RET), however, was significantly greater in Lophocebus. Discussion If ACS is a better predictor of fracture resistance than RET, then Cercocebus molars may be more fracture resistant than those of Lophocebus. Greater molar flare and proportional occlusal basin thickness might also afford Cercocebus molars greater fracture resistance.
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Affiliation(s)
| | - Gary T. Schwartz
- School of Human Evolution and Social Change and Institute of Human OriginsArizona State UniversityTempeArizonaUSA
| | - Mackie C. O'Hara
- Department of AnthropologyThe Ohio State UniversityColumbusOhioUSA
- School of Anthropology and ConservationUniversity of KentCanterburyUK
| | - Kaita Gurian
- Department of AnthropologyThe Ohio State UniversityColumbusOhioUSA
| | - Jess Rychel
- Department of AnthropologyThe Ohio State UniversityColumbusOhioUSA
| | - W. Scott McGraw
- Department of AnthropologyThe Ohio State UniversityColumbusOhioUSA
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Rossie JB, Cote SM. Additional hominoid fossils from the early Miocene of the Lothidok Formation, Kenya. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 179:261-275. [PMID: 36790670 DOI: 10.1002/ajpa.24594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 03/23/2022] [Accepted: 06/06/2022] [Indexed: 11/07/2022]
Abstract
OBJECTIVES Hominoid fossils are abundant at early Miocene fossil sites in the Lothidok Range, located directly west of Lake Turkana in northern Kenya. The West Turkana Miocene Project (WTMP) has worked in the Lothidok Range since 2008 with the goal of further elucidating the paleobiology of the hominoids through the recovery of new specimens and detailed documentation of their paleoecological context. To date our research has focused largely on the Kalodirr and Moruorot Site Complexes, both radiometrically dated to ~17.5-16.8 Ma. MATERIALS AND METHODS Our ongoing fieldwork at the Kalodirr Site Complex resulted in the discovery of new dentognathic specimens of the three previously identified species of fossil hominoids-Turkanapithecus kalakolensis, Simiolus enjiessi, and Afropithecus turkanensis. RESULTS A new mandible and an isolated M3 of T. kalakolensis from Kalodirr further clarify the lower molar morphology of the species and permit identification of KNM-MO 1 as a mandible of T. kalakolensis. A new mandible of S. enjiessi provides evidence of the relative proportions of the first and second lower molars. A new male specimen of A. turkanensis shows unusual P4 morphology that may be a developmental anomaly or a previously unknown morphological variant. DISCUSSION An improved understanding of the lower molar morphology of T. kalakolensis further strengthens its identification as a nyanzapithecine. Our new specimens and subsequent re-identification of existing collections makes it clear that all three Lothidok hominoids are known from both the Moruorot and Kalodirr Site Complexes. The Lothidok Range holds great promise for further documenting hominoid evolution.
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Affiliation(s)
- James B Rossie
- Department of Anthropology, Stony Brook University, Stony Brook, New York, USA
| | - Susanne M Cote
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
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Pozzi L, Penna A. Rocks and clocks revised: New promises and challenges in dating the primate tree of life. Evol Anthropol 2022; 31:138-153. [PMID: 35102633 DOI: 10.1002/evan.21940] [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: 12/02/2020] [Revised: 10/04/2021] [Accepted: 01/12/2022] [Indexed: 01/14/2023]
Abstract
In recent years, multiple technological and methodological advances have increased our ability to estimate phylogenies, leading to more accurate dating of the primate tree of life. Here we provide an overview of the limitations and potentials of some of these advancements and discuss how dated phylogenies provide the crucial temporal scale required to understand primate evolution. First, we review new methods, such as the total-evidence dating approach, that promise a better integration between the fossil record and molecular data. We then explore how the ever-increasing availability of genomic-level data for more primate species can impact our ability to accurately estimate timetrees. Finally, we discuss more recent applications of mutation rates to date divergence times. We highlight example studies that have applied these approaches to estimate divergence dates within primates. Our goal is to provide a critical overview of these new developments and explore the promises and challenges of their application in evolutionary anthropology.
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Affiliation(s)
- Luca Pozzi
- Department of Anthropology, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Anna Penna
- Department of Anthropology, The University of Texas at San Antonio, San Antonio, Texas, USA
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de Vries D, Heritage S, Borths MR, Sallam HM, Seiffert ER. Widespread loss of mammalian lineage and dietary diversity in the early Oligocene of Afro-Arabia. Commun Biol 2021; 4:1172. [PMID: 34621013 PMCID: PMC8497553 DOI: 10.1038/s42003-021-02707-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 09/21/2021] [Indexed: 11/16/2022] Open
Abstract
Diverse lines of geological and geochemical evidence indicate that the Eocene-Oligocene transition (EOT) marked the onset of a global cooling phase, rapid growth of the Antarctic ice sheet, and a worldwide drop in sea level. Paleontologists have established that shifts in mammalian community structure in Europe and Asia were broadly coincident with these events, but the potential impact of early Oligocene climate change on the mammalian communities of Afro-Arabia has long been unclear. Here we employ dated phylogenies of multiple endemic Afro-Arabian mammal clades (anomaluroid and hystricognath rodents, anthropoid and strepsirrhine primates, and carnivorous hyaenodonts) to investigate lineage diversification and loss since the early Eocene. These analyses provide evidence for widespread mammalian extinction in the early Oligocene of Afro-Arabia, with almost two-thirds of peak late Eocene diversity lost in these clades by ~30 Ma. Using homology-free dental topographic metrics, we further demonstrate that the loss of Afro-Arabian rodent and primate lineages was associated with a major reduction in molar occlusal topographic disparity, suggesting a correlated loss of dietary diversity. These results raise new questions about the relative importance of global versus local influences in shaping the evolutionary trajectories of Afro-Arabia's endemic mammals during the Oligocene.
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Affiliation(s)
- Dorien de Vries
- Ecosystems and Environment Research Centre, School of Science, Engineering and Environment, University of Salford, Manchester, UK
- Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Steven Heritage
- Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY, 11794, USA
- Duke Lemur Center Museum of Natural History, Durham, NC, 27705, USA
| | - Matthew R Borths
- Duke Lemur Center Museum of Natural History, Durham, NC, 27705, USA
| | - Hesham M Sallam
- Duke Lemur Center Museum of Natural History, Durham, NC, 27705, USA
- Mansoura University Vertebrate Paleontology, Department of Geology, Faculty of Science, Mansoura, Egypt
- Institute of Global Health and Human Ecology (I-GHHE), School of Sciences and Engineering, American University in Cairo, New Cairo, Egypt
| | - Erik R Seiffert
- Duke Lemur Center Museum of Natural History, Durham, NC, 27705, USA.
- Department of Integrative Anatomical Sciences, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA.
- Department of Mammalogy, Natural History Museum of Los Angeles County, Los Angeles, CA, 90007, USA.
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Locke EM, Benefit BR, Kimock CM, Miller ER, Nengo I. New dentognathic fossils of Noropithecus bulukensis (Primates, Victoriapithecidae) from the late Early Miocene of Buluk, Kenya. J Hum Evol 2020; 148:102886. [PMID: 33031954 DOI: 10.1016/j.jhevol.2020.102886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 08/28/2020] [Accepted: 08/28/2020] [Indexed: 10/23/2022]
Abstract
The late Early Miocene site of Buluk, Kenya, has yielded fossil remains of several catarrhine primates, including 16 dentognathic specimens of the stem cercopithecoid Noropithecus bulukensis. With the exception of the large sample of Victoriapithecus macinnesi from the middle Miocene of Maboko Island, Kenya, the majority of stem cercopithecoid taxa are represented by small sample sizes. We describe and analyze 91 new cercopithecoid fossils collected from Buluk between 2004 and 2018, including several previously undescribed tooth positions for N. bulukensis, and provide the first evaluation of dental metric and morphological variation in this sample. The results show that the expanded Buluk sample exhibits high levels of dental variation in the postcanine tooth row, similar to V. macinnesi at Maboko, but this variation is consistent with a single-species hypothesis. Subtle differences in the shape of the I1, breadth of the C1 and P3, relative breadth of M1, upper and lower molar distal shelf lengths, the degree of M2 basal flare, and a less-developed lower molar distal lophid differentiate the dentition of N. bulukensis from V. macinnesi. Although differences exist between the N. bulukensis and V. macinnesi dental samples, the high degree of variation within each sample complicates the identification of many individual specimens. New partial maxillae and mandibles allow reassessment of previously described diagnostic differences between N. bulukensis and V. macinnesi, negating upper molar arcade shape as a diagnostic feature and confirming the existence of differences in mandibular symphyseal morphology. Overall, new fossils from Buluk provide new evidence of the dentognathic anatomy of a medium-sized cercopithecoid that coexisted with a diverse group of noncercopithecoid catarrhines at the end of the early Miocene.
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Affiliation(s)
- Ellis M Locke
- Institute of Human Origins, Arizona State University, Tempe, AZ, 85282, USA; School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, 85282, USA.
| | - Brenda R Benefit
- Department of Anthropology, New Mexico State University, Las Cruces, NM, 88003, USA
| | - Clare M Kimock
- Center for the Study of Human Origins, Department of Anthropology, New York University, New York, NY, 10003, USA; New York Consortium in Evolutionary Primatology, New York, NY, 10003, USA
| | - Ellen R Miller
- Department of Anthropology, Wake Forest University, Winston-Salem, NC, 27106, USA
| | - Isaiah Nengo
- Turkana Basin Institute, Stony Brook University, Stony Brook, NY, 11794, USA
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Monson TA. Patterns and magnitudes of craniofacial covariation in extant cercopithecids. Anat Rec (Hoboken) 2020; 303:3068-3084. [PMID: 32220100 DOI: 10.1002/ar.24398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 01/15/2020] [Accepted: 01/25/2020] [Indexed: 01/17/2023]
Abstract
The cranium contains almost all of the vertebrate sensory organs and plays an essential role in vertebrate evolution. Research on the primate cranium has revealed that it is both highly integrated and modular, but studies have historically focused on covariance between the neurocranium and facial skeleton rather than on bones specific to special senses such as vision. The goal of this work is to investigate patterns and magnitudes of craniofacial covariation in extant cercopithecids with particular attention to the orbits. This study takes a quantitative approach using data collected from 38 homologous cranial landmarks across 11 genera of cercopithecid monkeys (Cercopithecidae, N = 291). These data demonstrate that both patterns and magnitudes of craniofacial covariation differ across Cercopithecidae at subfamily, tribe, and genus levels, with the strongest integration in the papionins (and specifically Papio) and significantly weaker covariation in the colobines, particularly Presbytis. Orbital height does not covary with other measurements of the cranium to the same degree as other cranial traits in Cercopithecidae and is highly constrained across the family. This study has important implications for our understanding of the evolution and development of morphological diversity in the cercopithecid cranium and evolution of the primate eye. This study also highlights the potential error of broad assumptions about generalizing patterns and magnitudes of modularity and integration across primates. Additionally, these findings reiterate the importance of trait selection for interpreting fossil taxonomy, as craniofacial covariation may impact phenotypes commonly used to differentiate fossil primate species.
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Affiliation(s)
- Tesla A Monson
- Department of Anthropology, Western Washington University, Bellingham, Washington, USA
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