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Bertrand OC, Jiménez Lao M, Shelley SL, Wible JR, Williamson TE, Meng J, Brusatte SL. The virtual brain endocast of Trogosus (Mammalia, Tillodontia) and its relevance in understanding the extinction of archaic placental mammals. J Anat 2024; 244:1-21. [PMID: 37720992 PMCID: PMC10734658 DOI: 10.1111/joa.13951] [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: 06/10/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/19/2023] Open
Abstract
After successfully diversifying during the Paleocene, the descendants of the first wave of mammals that survived the end-Cretaceous mass extinction waned throughout the Eocene. Competition with modern crown clades and intense climate fluctuations may have been part of the factors leading to the extinction of these archaic groups. Why these taxa went extinct has rarely been studied from the perspective of the nervous system. Here, we describe the first virtual endocasts for the archaic order Tillodontia. Three species from the middle Eocene of North America were analyzed: Trogosus hillsii, Trogosus grangeri, and Trogosus castoridens. We made morphological comparisons with the plaster endocast of another tillodont, Tillodon fodiens, as well as groups potentially related to Tillodontia: Pantodonta, Arctocyonidae, and Cimolesta. Trogosus shows very little inter-specific variation with the only potential difference being related to the fusion of the optic canal and sphenorbital fissure. Many ancestral features are displayed by Trogosus, including an exposed midbrain, small neocortex, orbitotemporal canal ventral to rhinal fissure, and a broad circular fissure. Potential characteristics that could unite Tillodontia with Pantodonta, and Arctocyonidae are the posterior position of cranial nerve V3 exit in relation to the cerebrum and the low degree of development of the subarcuate fossa. The presence of large olfactory bulbs and a relatively small neocortex are consistent with a terrestrial lifestyle. A relatively small neocortex may have put Trogosus at risk when competing with artiodactyls for potentially similar resources and avoiding predation from archaic carnivorans, both of which are known to have had larger relative brain and neocortex sizes in the Eocene. These factors may have possibly exacerbated the extinction of Tillodontia, which showed highly specialized morphologies despite the increase in climate fluctuations throughout the Eocene, before disappearing during the middle Eocene.
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Affiliation(s)
- Ornella C Bertrand
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Edifici ICTA-ICP, Cerdanyola del Vallès, Barcelona, Spain
- School of GeoSciences, Grant Institute, University of Edinburgh, Edinburgh, Scotland, UK
| | - Marina Jiménez Lao
- School of GeoSciences, Grant Institute, University of Edinburgh, Edinburgh, Scotland, UK
| | - Sarah L Shelley
- School of GeoSciences, Grant Institute, University of Edinburgh, Edinburgh, Scotland, UK
- Section of Mammals, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA
| | - John R Wible
- Section of Mammals, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA
| | - Thomas E Williamson
- New Mexico Museum of Natural History and Science, Albuquerque, New Mexico, USA
| | - Jin Meng
- Division of Paleontology, American Museum of Natural History, New York, New York, USA
| | - Stephen L Brusatte
- School of GeoSciences, Grant Institute, University of Edinburgh, Edinburgh, Scotland, UK
- New Mexico Museum of Natural History and Science, Albuquerque, New Mexico, USA
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White CL, Bloch JI, Morse PE, Silcox MT. Virtual endocast of late Paleocene Niptomomys (Microsyopidae, Euarchonta) and early primate brain evolution. J Hum Evol 2023; 175:103303. [PMID: 36608392 DOI: 10.1016/j.jhevol.2022.103303] [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: 08/05/2021] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 01/05/2023]
Abstract
Paleogene microsyopid plesiadapiforms are among the oldest euarchontans known from relatively complete crania. While cranial endocasts are known for larger-bodied Eocene microsyopine microsyopids, this study documents the first virtual endocast for the more diminutive uintasoricine microsyopids, derived from a specimen of Niptomomys cf. Niptomomys doreenae (USNM 530198) from the late Paleocene of Wyoming. Size estimates of smaller-bodied uintasoricines are similar to those inferred for the common ancestor of Primates, so the virtual endocast of Niptomomys may provide a useful model to study early primate brain evolution. Due to the broken and telescoped nature of the neurocranium of USNM 530198, a μCT scan of the specimen was used to create a 3D model of multiple bone fragments that were then independently isolated, repositioned, and merged to form a cranial reconstruction from which a virtual endocast was extracted. The virtual endocast of Niptomomys has visible caudal colliculi, suggesting less caudal expansion of the cerebrum compared to that of euprimates, but similar to that of several other plesiadapiforms. The part of the endocast representing the olfactory bulbs is larger relative to overall endocast volume in Niptomomys (8.61%) than that of other known plesiadapiforms (∼5%) or euprimates (<3.5%). The petrosal lobules (associated with visual stabilization) are relatively large for a Paleocene placental mammal (1.66%). The encephalization quotient of Niptomomys is relatively high (range = 0.35-0.85) compared to that of Microsyops (range = 0.32-0.52), with the upper estimates in the range of values calculated for early euprimates. However, this contrast likely relates in part to the small size of the taxon, and is not associated with evidence of neocortical expansion. These findings are consistent with a model of shifting emphasis in primate evolution toward functions of the cerebrum and away from olfaction with the origin of euprimates.
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Affiliation(s)
- Chelsea L White
- Department of Anthropology, University of Toronto Scarborough, 1265 Military Trail, Scarborough, Ontario, M1C 1A4, Canada
| | - Jonathan I Bloch
- Florida Museum of Natural History, University of Florida, P.O. Box 117800, Gainesville, FL, 32611-7800, USA
| | - Paul E Morse
- Florida Museum of Natural History, University of Florida, P.O. Box 117800, Gainesville, FL, 32611-7800, USA; Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Mary T Silcox
- Department of Anthropology, University of Toronto Scarborough, 1265 Military Trail, Scarborough, Ontario, M1C 1A4, Canada.
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Goswami A, Noirault E, Coombs EJ, Clavel J, Fabre AC, Halliday TJD, Churchill M, Curtis A, Watanabe A, Simmons NB, Beatty BL, Geisler JH, Fox DL, Felice RN. Attenuated evolution of mammals through the Cenozoic. Science 2022; 378:377-383. [DOI: 10.1126/science.abm7525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Cenozoic diversification of placental mammals is the archetypal adaptive radiation. Yet, discrepancies between molecular divergence estimates and the fossil record fuel ongoing debate around the timing, tempo, and drivers of this radiation. Analysis of a three-dimensional skull dataset for living and extinct placental mammals demonstrates that evolutionary rates peak early and attenuate quickly. This long-term decline in tempo is punctuated by bursts of innovation that decreased in amplitude over the past 66 million years. Social, precocial, aquatic, and herbivorous species evolve fastest, especially whales, elephants, sirenians, and extinct ungulates. Slow rates in rodents and bats indicate dissociation of taxonomic and morphological diversification. Frustratingly, highly similar ancestral shape estimates for placental mammal superorders suggest that their earliest representatives may continue to elude unequivocal identification.
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Affiliation(s)
- Anjali Goswami
- Department of Life Sciences, Natural History Museum, London, UK
- Department of Genetics, Evolution, and Environment, University College London, London, UK
| | - Eve Noirault
- Department of Life Sciences, Natural History Museum, London, UK
| | - Ellen J. Coombs
- Department of Life Sciences, Natural History Museum, London, UK
- Department of Genetics, Evolution, and Environment, University College London, London, UK
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Julien Clavel
- Université Lyon, Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023 LEHNA, Villeurbanne, France
| | - Anne-Claire Fabre
- Department of Life Sciences, Natural History Museum, London, UK
- Naturhistorisches Museum Bern, Bern, Switzerland
- Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Thomas J. D. Halliday
- Department of Life Sciences, Natural History Museum, London, UK
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Morgan Churchill
- Department of Biology, University of Wisconsin Oshkosh, Oshkosh, WI, USA
| | - Abigail Curtis
- Department of Biology, University of Washington, Seattle, WA, USA
| | - Akinobu Watanabe
- Department of Life Sciences, Natural History Museum, London, UK
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, NY, USA
- Division of Paleontology, American Museum of Natural History, New York, NY, USA
| | - Nancy B. Simmons
- Department of Mammalogy, Division of Vertebrate Zoology, American Museum of Natural History, New York, NY, USA
| | - Brian L. Beatty
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, NY, USA
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Jonathan H. Geisler
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, New York, NY, USA
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - David L. Fox
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Ryan N. Felice
- Department of Life Sciences, Natural History Museum, London, UK
- Department of Genetics, Evolution, and Environment, University College London, London, UK
- Centre for Integrative Anatomy, Department of Cell and Developmental Biology, University College London, London, UK
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4
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Bertrand OC, Shelley SL, Williamson TE, Wible JR, Chester SGB, Flynn JJ, Holbrook LT, Lyson TR, Meng J, Miller IM, Püschel HP, Smith T, Spaulding M, Tseng ZJ, Brusatte SL. Brawn before brains in placental mammals after the end-Cretaceous extinction. Science 2022; 376:80-85. [PMID: 35357913 DOI: 10.1126/science.abl5584] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Mammals are the most encephalized vertebrates, with the largest brains relative to body size. Placental mammals have particularly enlarged brains, with expanded neocortices for sensory integration, the origins of which are unclear. We used computed tomography scans of newly discovered Paleocene fossils to show that contrary to the convention that mammal brains have steadily enlarged over time, early placentals initially decreased their relative brain sizes because body mass increased at a faster rate. Later in the Eocene, multiple crown lineages independently acquired highly encephalized brains through marked growth in sensory regions. We argue that the placental radiation initially emphasized increases in body size as extinction survivors filled vacant niches. Brains eventually became larger as ecosystems saturated and competition intensified.
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Affiliation(s)
- Ornella C Bertrand
- School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, Scotland EH9 3FE, UK
| | - Sarah L Shelley
- School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, Scotland EH9 3FE, UK.,Section of Mammals, Carnegie Museum of Natural History, Pittsburgh, PA, USA
| | | | - John R Wible
- Section of Mammals, Carnegie Museum of Natural History, Pittsburgh, PA, USA
| | - Stephen G B Chester
- Department of Anthropology, Brooklyn College, City University of New York, Brooklyn, NY, USA.,Department of Anthropology, The Graduate Center, City University of New York, New York, NY, USA.,New York Consortium in Evolutionary Primatology, New York, NY, USA
| | - John J Flynn
- Division of Paleontology, American Museum of Natural History, New York, NY, USA.,Department of Earth and Environmental Sciences, Columbia University, New York, NY, USA.,Ecology, Evolutionary Biology, and Behavior subprogram, PhD Program in Biology, The Graduate Center, City University of New York, New York, NY, USA.,PhD Program in Earth and Environmental Sciences, The Graduate Center, City University of New York, New York, NY, USA
| | - Luke T Holbrook
- Department of Biological Sciences, Rowan University, Glassboro, NJ, USA
| | | | - Jin Meng
- Division of Paleontology, American Museum of Natural History, New York, NY, USA
| | - Ian M Miller
- Denver Museum of Nature & Science, Denver, CO, USA.,National Geographic Society, Washington, DC, USA
| | - Hans P Püschel
- School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, Scotland EH9 3FE, UK
| | - Thierry Smith
- Directorate Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium
| | - Michelle Spaulding
- Department of Biological Sciences, Purdue University Northwest, Westville, IN, USA
| | - Z Jack Tseng
- Department of Integrative Biology and Museum of Paleontology, University of California, Berkeley, CA, USA
| | - Stephen L Brusatte
- School of GeoSciences, University of Edinburgh, Grant Institute, Edinburgh, Scotland EH9 3FE, UK.,New Mexico Museum of Natural History and Science, Albuquerque, NM, USA
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5
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Ferreira JD, Dozo MT, de Moura Bubadué J, Kerber L. Morphology and postnatal ontogeny of the cranial endocast and paranasal sinuses of capybara (Hydrochoerus hydrochaeris), the largest living rodent. J Morphol 2021; 283:66-90. [PMID: 34775628 DOI: 10.1002/jmor.21428] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 11/04/2021] [Accepted: 11/07/2021] [Indexed: 01/22/2023]
Abstract
Recent studies have analyzed and described the endocranial cavities of caviomorph rodents. However, no study has documented the changes in the morphology and relative size of such cavities during ontogeny. Expecting to contribute to the discussion of the endocranial spaces of extinct caviomorphs, we aimed to characterize the cranial endocast morphology and paranasal sinuses of the largest living rodent, Hydrochoerus hydrochaeris, by focusing on its ontogenetic growth patterns. We analyzed 12 specimens of different ontogenetic stages and provided a comparison with other cavioids. Our study demonstrates that the adult cranial endocast of H. hydrochaeris is characterized by olfactory bulbs with an irregular shape, showing an elongated olfactory tract without a clear circular fissure, a marked temporal region that makes the endocast with rhombus outline, and gyrencephaly. Some of these traits change as the brain grows. The cranial pneumatization is present in the frontal and lacrimal bones. We identified two recesses (frontal and lacrimal) and one sinus (frontal). These pneumatic cavities increase their volume as the cranium grows, covering the cranial region of the cranial endocast. The encephalization quotient was calculated for each specimen, demonstrating that it decreases as the individual grows, being much higher in younger specimens than in adults. Our results show that the ontogenetic stage can be a confounding factor when it comes to the general patterns of encephalization of extinct rodents, reinforcing the need for paleobiologists to take the age of the specimens into account in future studies on this subject to avoid age-related biases.
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Affiliation(s)
- José D Ferreira
- Programa de Pós-Graduação em Biodiversidade Animal, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, Brazil.,Centro de Apoio à Pesquisa Paleontológica da Quarta Colônia, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Maria Teresa Dozo
- Instituto Patagónico de Geología y Paleontología, CCT CONICET-CENPAT, Puerto Madryn, Argentina
| | - Jamile de Moura Bubadué
- Laboratório de Ciências Ambientais, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Brazil
| | - Leonardo Kerber
- Programa de Pós-Graduação em Biodiversidade Animal, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, Brazil.,Centro de Apoio à Pesquisa Paleontológica da Quarta Colônia, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, Brazil.,Museu Paraense Emílio Goeldi, Coordenação de Ciências da Terra e Ecologia, Belém, Brazil
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6
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Pampush JD, Fuselier EJ, Yapuncich GS. Using BayesModelS to provide Bayesian- and phylogenetically-informed primate body mass predictions. J Hum Evol 2021; 161:103077. [PMID: 34688978 DOI: 10.1016/j.jhevol.2021.103077] [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: 12/09/2019] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 10/20/2022]
Abstract
An accurate prediction of the body mass of an extinct species can greatly inform the reconstruction of that species' ecology. Therefore, paleontologists frequently predict the body mass of extinct taxa from fossilized materials, particularly dental dimensions. Body mass prediction has traditionally been performed in a frequentist statistical framework, and accounting for phylogenetic relationships while calibrating prediction models has only recently become more commonplace. In this article, we apply BayesModelS-a phylogenetically informed Bayesian prediction method-to predict body mass in a sample of 49 euarchontan species (24 strepsirrhines, 20 platyrrhines, 3 tarsiids, 1 dermopteran, and 1 scandentian) and compare this approach's body mass prediction accuracy with other commonly used techniques, namely ordinary least squares, phylogenetic generalized least squares, and phylogenetic independent contrasts (PICs). When predicting the body masses of extant euarchontans from dental and postcranial variables, BayesModelS and PICs have substantially higher predictive accuracy than ordinary least squares and phylogenetic generalized least squares. The improved performances of BayesModelS and PIC are most evident for dentally derived body mass proxies or when body mass proxies have high degrees of phylogenetic covariance. Predicted values generated by BayesModelS and PIC methods also show less variance across body mass proxies when applied to the Eocene adapiform Notharctus tenebrosus. These more explicitly phylogenetically based methods should prove useful for predicting body mass in a paleontological context, and we provide executive scripts for both BayesModelS and PIC to increase ease of application.
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Affiliation(s)
- 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.
| | - Edward J Fuselier
- Department of Mathematical Sciences, High Point University, High Point, NC 27260, USA
| | - Gabriel S Yapuncich
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA; Medical Education Administration, Duke University School of Medicine, Durham, NC 27710, USA
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Jaeger JJ, Sein C, Gebo DL, Chaimanee Y, Nyein MT, Oo TZ, Aung MM, Suraprasit K, Rugbumrung M, Lazzari V, Soe AN, Chavasseau O. Amphipithecine primates are stem anthropoids: cranial and postcranial evidence. Proc Biol Sci 2020; 287:20202129. [PMID: 33171091 DOI: 10.1098/rspb.2020.2129] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Since their discovery in 1927, the phylogenetic status of the Myanmar amphipithecines has been highly debated. These fossil primates are recognized either as anthropoids or as adapiform strepsirrhines. This uncertainty was largely the consequence of a limited fossil record consisting mostly of jaw fragments but lacking the critical cranial elements that might resolve this debate. We report here cranial remains associated with an ulna from a single individual pertaining to the amphipithecine Ganlea megacanina. In addition to anthropoid-like dentognathic characters, Ganlea displays several ulna and skull features that testify to its anthropoid affinities (e.g. short subvertically oriented lacrimal duct, lacrimal foramen and bone inside the orbit, maxillary contribution to the lower orbital rim, fused metopic suture). By contrast to crown anthropoids, however, Ganlea lacks postorbital closure, confirming that postorbital closure appeared later than many anthropoid dentognathic characters and evolved convergently in extant tarsiers and anthropoids. Thus, amphipithecines must now be recognized as stem anthropoids offering a unique window on the early evolution of cranial and skeletal features in anthropoids, and reinforcing the hypothesis of an origin and early diversification of anthropoids in Asia.
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Affiliation(s)
- J-J Jaeger
- Laboratory PALEVOPRIM, UMR CNRS 7262, University of Poitiers, 6 Rue Michel Brunet, 86073 Poitiers Cedex 9, France
| | - C Sein
- Department of Higher Education, Ministry of Education, Naypyitaw 15011, Myanmar
| | - D L Gebo
- Department of Anthropology, Northern Illinois University, DeKalb, IL 60115, USA
| | - Y Chaimanee
- Laboratory PALEVOPRIM, UMR CNRS 7262, University of Poitiers, 6 Rue Michel Brunet, 86073 Poitiers Cedex 9, France
| | - M T Nyein
- Department of Underwater Archaeology, Field School of Archaeology, Pyay Township, Bago Region, Myanmar
| | - T Z Oo
- Department of Geology, East Yangon University, Thanlyin Township, Yangon, Myanmar
| | - M M Aung
- Department of Geology, East Yangon University, Thanlyin Township, Yangon, Myanmar
| | - K Suraprasit
- Department of Geology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - M Rugbumrung
- Department of Mineral Resources, Rama VI Road, Bangkok 10400, Thailand
| | - V Lazzari
- Laboratory PALEVOPRIM, UMR CNRS 7262, University of Poitiers, 6 Rue Michel Brunet, 86073 Poitiers Cedex 9, France
| | - A N Soe
- University of Distance Education, Mandalay 05023, Myanmar
| | - O Chavasseau
- Laboratory PALEVOPRIM, UMR CNRS 7262, University of Poitiers, 6 Rue Michel Brunet, 86073 Poitiers Cedex 9, France
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López-Torres S, Bertrand OC, Lang MM, Silcox MT, Fostowicz-Frelik Ł. Cranial endocast of the stem lagomorph Megalagus and brain structure of basal Euarchontoglires. Proc Biol Sci 2020; 287:20200665. [PMID: 32576117 PMCID: PMC7329053 DOI: 10.1098/rspb.2020.0665] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Early lagomorphs are central to our understanding of how the brain evolved in Glires (rodents, lagomorphs and their kin) from basal members of Euarchontoglires (Glires + Euarchonta, the latter grouping primates, treeshrews, and colugos). Here, we report the first virtual endocast of the fossil lagomorph Megalagus turgidus, from the Orella Member of the Brule Formation, early Oligocene, Nebraska, USA. The specimen represents one of the oldest nearly complete lagomorph skulls known. Primitive aspects of the endocranial morphology in Megalagus include large olfactory bulbs, exposure of the midbrain, a small neocortex and a relatively low encephalization quotient. Overall, this suggests a brain morphology closer to that of other basal members of Euarchontoglires (e.g. plesiadapiforms and ischyromyid rodents) than to that of living lagomorphs. However, the well-developed petrosal lobules in Megalagus, comparable to the condition in modern lagomorphs, suggest early specialization in that order for the stabilization of eye movements necessary for accurate visual tracking. Our study sheds new light on the reconstructed morphology of the ancestral brain in Euarchontoglires and fills a critical gap in the understanding of palaeoneuroanatomy of this major group of placental mammals.
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Affiliation(s)
- Sergi López-Torres
- Division of Paleontology, American Museum of Natural History, New York, NY, USA.,Richard Gilder Graduate School, American Museum of Natural History, New York, NY, USA.,New York Consortium in Evolutionary Primatology, New York, NY, USA.,Department of Evolutionary Paleobiology, Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland
| | - Ornella C Bertrand
- School of Geosciences, Grant Institute, University of Edinburgh, Edinburgh EH9 3FE, UK
| | - Madlen M Lang
- Department of Anthropology, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Mary T Silcox
- Department of Anthropology, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Łucja Fostowicz-Frelik
- Department of Evolutionary Paleobiology, Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland.,Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, People's Republic of China.,CAS Center for Excellence in Life and Paleoenvironment, Beijing 100044, People's Republic of China
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9
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Bertrand OC, San Martin‐Flores G, Silcox MT. Endocranial shape variation in the squirrel‐related clade and their fossil relatives using 3D geometric morphometrics: contributions of locomotion and phylogeny to brain shape. J Zool (1987) 2019. [DOI: 10.1111/jzo.12665] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- O. C. Bertrand
- School of GeoSciences University of Edinburgh Grant Institute Edinburgh UK
| | | | - M. T. Silcox
- Department of Anthropology University of Toronto Scarborough Toronto ON Canada
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10
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New Virtual Endocasts of Eocene Ischyromyidae and Their Relevance in Evaluating Neurological Changes Occurring Through Time in Rodentia. J MAMM EVOL 2018. [DOI: 10.1007/s10914-017-9425-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Boyer DM, Harrington AR. Scaling of bony canals for encephalic vessels in euarchontans: Implications for the role of the vertebral artery and brain metabolism. J Hum Evol 2017; 114:85-101. [PMID: 29447763 DOI: 10.1016/j.jhevol.2017.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 09/01/2017] [Accepted: 09/02/2017] [Indexed: 01/07/2023]
Abstract
Supplying the central nervous system with oxygen and glucose for metabolic activities is a critical function for all animals at physiologic, anatomical, and behavioral levels. A relatively proximate challenge to nourishing the brain is maintaining adequate blood flow. Euarchontans (primates, dermopterans and treeshrews) display a diversity of solutions to this challenge. Although the vertebral artery is a major encephalic vessel, previous research has questioned its importance for irrigating the cerebrum. This presents a puzzling scenario for certain strepsirrhine primates (non-cheirogaleid lemuriforms) that have reduced promontorial branches of the internal carotid artery and no apparent alternative encephalic vascular route except for the vertebral artery. Here, we present results of phylogenetic comparative analyses of data on the cross-sectional area of bony canals that transmit the vertebral artery (transverse foramina). These results show that, across primates (and within major primate subgroups), variation in the transverse foramina helps significantly to explain variation in forebrain mass even when variation in promontorial canal cross-sectional areas are also considered. Furthermore, non-cheirogaleid lemuriforms have larger transverse foramina for their endocranial volume than other euarchontans, suggesting that the vertebral arteries compensate for reduced promontorial artery size. We also find that, among internal carotid-reliant euarchontans, species that are more encephalized tend to have a promontorial canal that is larger relative to the transverse foramina. Tentatively, we consider the correlation between arterial canal diameters (as a proxy for blood flow) and brain metabolic demands. The results of this analysis imply that human investment in brain metabolism (∼27% of basal metabolic rate) may not be exceptional among euarchontans.
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Affiliation(s)
- Doug M Boyer
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA.
| | - Arianna R Harrington
- Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA
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Bernardi M, Couette S. Eocene Paleoecology ofAdapis parisiensis(Primate, Adapidae): From Inner Ear to Lifestyle. Anat Rec (Hoboken) 2017; 300:1576-1588. [DOI: 10.1002/ar.23609] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/03/2017] [Accepted: 02/13/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Margot Bernardi
- EPHE, PSL Research University, Paris; Dijon 21000 France
- Biogéosciences, UMR CNRS 6282; Univ Bourgogne Franche-Comté; 6 Bd Gabriel Dijon 21000 France
| | - Sébastien Couette
- EPHE, PSL Research University, Paris; Dijon 21000 France
- Biogéosciences, UMR CNRS 6282; Univ Bourgogne Franche-Comté; 6 Bd Gabriel Dijon 21000 France
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Gilbert CC, Jungers WL. Comment on relative brain size in early primates and the use of encephalization quotients in primate evolution. J Hum Evol 2017; 109:79-87. [PMID: 28587753 DOI: 10.1016/j.jhevol.2017.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 04/06/2017] [Accepted: 04/26/2017] [Indexed: 10/19/2022]
Affiliation(s)
- Christopher C Gilbert
- Department of Anthropology, Hunter College of the City University of New York, 695 Park Avenue, New York, NY 10065, USA; PhD Programs in Anthropology and Biology, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA; New York Consortium in Evolutionary Primatology, USA.
| | - William L Jungers
- Department of Anatomical Sciences, School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; Association Vahatra, Antananarivo 101, Madagascar
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