DOCSLIB.ORG

Supporting Online Material

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Supporting Online Material Supplementary Information for Quantitative assessment of tarsal morphology illuminates locomotor behaviour in Paleocene mammals following the end-Cretaceous mass extinction Sarah L. Shelleya,b,1, Stephen L. Brusattea, Thomas E. Williamsonc aSchool of GeoSciences, Grant Institute, University of Edinburgh, James Hutton Road, King's Buildings, Edinburgh, EH9 3FE, United Kingdom. bSection of Mammals, Carnegie Museum of Natural History, 5800 Baum Blvd, Pittsburgh, Pennsylvania, 15206, United States of America (previous address). cNew Mexico Museum of Natural History and Science, 1801 Mountain Rd NW, Albuquerque, New Mexico, 87104, United States of America. 1To whom correspondence should be addressed. Email: [email protected] (SLS) This PDF file includes: Supplementary text Figs. S1 to S24 Tables S1 to S16 References for SI Other supplementary materials for this manuscript include the following: Datasets S1 to S5 1 Supplementary Information Text Methods Datasets Tarsal data. Measurements. 29 tarsal measurements (Fig. S1) were taken from the astragalus and calcaneum for a sample of extant and fossil mammals (Dataset S1). Note we refer to these measurements as tarsal measurements for ease of reading but recognise that they are from only two tarsal bones. Measurements were taken with the tarsals orientated as if the taxon being measured were plantigrade to maintain consistency in terminology. The following list of measurements is based on personal observation of tarsal osteology and compiled to describe the morphological and functional variation of the bones thoroughly, whilst also remaining measurable for as many taxa as possible. Note that there are some zero values in our measurements: zero values indicate the absence or loss of a given feature in the view measured which in itself is a character. In some instances, extinct taxon measurements are composited. This was done with care and only where the specimens closely approximate each other in size (often times the specimens are found in close association but cannot be determined to be from the same individual or have been accessioned separately). Specimen numbers are listed in Dataset S1. List of measurements used in this study corresponding to those illustrated in Fig. S1b: 17 measurements were taken from the astragalus: A1 maximum anteroposterior length of the astragalus A2 maximum anteroposterior length of the astragalar body A3 maximum anteroposterior length of the medial trochlear keel (highest edge) A4 maximum anteroposterior length of the lateral trochlear keel (highest edge) A5 maximum mediolateral width of astragalar body A6 maximum width or length of posteromedial expansion 2 A7 maximum width of fibial facet in dorsal view A8 maximum mediolateral width of trochlea at anterior border A9 maximum mediolateral width of astragalar head A10 maximum length of ectal facet A11 maximum anteroposterior length of sustentacular facet A12 maximum mediolateral width of sustentacular facet A13 maximum dorsoplantar depth of astragalar body A14 maximum dorsoplantar depth of astragalar head A15 maximum dorsoplantar height of lateral trochlear keel A16 maximum dorsoplantar height of medial trochlear keel A17 maximum anteroposterior length between anterior medial rim of trochlear and anterior margin of astragalar head 12 measurements were taken from the calcaneum: C1 maximum anteroposterior length of the calcaneum C2 maximum anteroposterior length of the calcaneal tuber C3 maximum mediolateral width of the posterior end of the calcaneum C4 maximum mediolateral width of the calcaneal body C5 minimum mediolateral width of the calcaneal tuber C6 maximum anteroposterior length of the sustentacular facet C7 maximum mediolateral width of the sustentacular facet C8 maximum length of the ectal facet C9 maximum width of the ectal facet C10 maximum dorsoplantar depth of the calcaneal tuber C11 maximum dorsoplantar depth of the cuboid facet C12 maximum mediolateral width of the cuboid facet Taxon sample. Extant taxa. We sampled a total of 85 extant therian taxa. Given the improbability of measuring tarsals for every extant mammal species, we aimed to build a proxy dataset by 3 selecting taxa that were relatively straightforward to assign to a given locomotor group, covered all extant orders that locomote primarily on land, and covered a broad range of locomotor behaviours that occur on land. This number includes representatives for every pertinent placental order with the exception of Chiroptera, Dermoptera, Pholidota and Sirenia. We did not include extant representatives for Chiroptera given they do not use their hindlimbs for sustained locomotion on land (although we recognise the unusual exception of mystacinid bats). We also chose to not include dermopterans in this study given their extreme morphologies and outlier position in morphospace associated with gliding behaviour (e.g. see [1] but also [2]) and the fact we were not able to obtain enough measurements for ostensible Paleocene dermopterans to include in our dataset (e.g. Mixodectes) [3]. We did not include Pholidota given they possess highly unusual tarsal bones (i.e. extreme reduction of the sustentacular facet) making meaningful inclusion into this dataset difficult. We also excluded Sirenia given that they lack tarsal bones. We note that 85 out of 6490 extant eutherian mammals species or 72 out of 1311 genera [4] is sampling slightly over 1% of extant mammal species and 5.5% of genera. This value is diminutive, however, consider that how species are defined does likely not directly correlate with tarsal diversity. Furthermore, when breaking down the taxonomic composition of extant species, 2552 of extant species are rodents (many of which are recognised by genotypic rather than phenotypic features) and we have sampled across a range of rodents exhibiting an exemplary range of morphologies and locomotor behaviours; 1386 species are bats which are not pertinent to this current study; 551 are artiodactyls which although relevant are relatively constrained in their tarsal morphology and locomotor behaviours (with the exception of extant cetaceans which lack tarsals and were therefore not included in our dataset). This is the same rationale commonly used in phylogenetic analyses using morphological data; for example, the Mammal Tree of Life project used 46 taxa to represent the diversity of extant mammals [5]. Furthermore, we utilise discriminant analyses to test the validity of our data sample at predicting locomotor behaviour—the results of this analysis show that tarsals can be used to predict locomotor behaviour accurately in our dataset, and thus this dataset is useful for our purposes. 4 Paleocene taxa. We were able to measure a total of 40 Paleocene taxa. A core aim of this project was to incorporate as many Paleocene mammals as possible. These mostly belonged to so-called ‘archaic’ groups but also included species considered to be members (or stem members) of extant orders. In our sample we have chosen to include species of Eocene age known for tarsal bones which have a generic temporal range that extends back into the Paleocene. Taxon age information is provided in Dataset S1. Cretaceous taxa. We sampled a total of five Cretaceous species. We chose to not extend our sample outside of Cladotheria as taking homologous measurements would have become difficult. To this end, our sample includes cladotherians known from three- dimensionally preserved tarsal specimens for which we were able to obtain the necessary measurements. Notable exceptions include Zalambdalestes [6] and Asioryctes which are known for tarsal bones but for which we could not obtain enough measurements to include in this study. Regression data. Five measurements were taken for a sample of 79 extant therian taxa and four extinct Paleocene taxa (Dataset S5). Our fossil sample was limited to specimens that allowed for body weight estimates to be calculated using associated postcranial material (see below) List of measurements used for regression analyses: Maximum proximodistal length of the humerus Minimum midshaft circumference of the humerus Maximum mediolateral width of the humerus Maximum proximodistal length of the femur Minimum midshaft circumference of the femur Institutional abbreviations AMNH, American Museum of Natural History, New York, New York, USA CM, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA 5 CNHM, Chicago Natural History Museum, Chicago, Illinois, USA DGM, Divisão Nacional de Producão Mineral, Rio de Janeiro, Brazil IMM, Inner Mongolian Museum, Hohhot, Inner Mongolia, China IPPAS, Institute of Palaeozoology, Polish Academy of Sciences, Warsaw, Poland IRSNB, Royal Belgian Institute of Natural Sciences, Brussels, Belgium. ISEZ, Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Kraków, Poland IVPP, Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China; MACN, Museo Argentino de Ciencias Naturales, Buenos Aires, Argentina MHNC, Museo de Historia Natural “Alcide d’Orbigny”, Cochabamba, Bolivia; MNHN, Muséum national d’Histoire naturelle, Paris, France NMMNH, New Mexico Museum of Natural History and Science, Albuquerque, New Mexico, USA NMS, National Museum of Scotland, Edinburgh, UK PSS-MAE, Paleontological and Stratigraphy Branch (Geological Institute), Mongolian Academy of Sciences – American Museum of Natural History Expeditions, Ulaanbaatar, Mongolia UCMP, Museum of Paleontology, University of California, Berkeley, California, USA; UF, Vertebrate Paleontology collection, Florida
Load more

Recommended publications
  • Paleoenvironment of the Late Eocene Chadronian-Age Whitehead Creek Locality (Northwestern Nebraska)
    St. Cloud State University theRepository at St. Cloud State Culminating Projects in Cultural Resource Management Department of Anthropology 10-2019 Paleoenvironment of the Late Eocene Chadronian-Age Whitehead Creek Locality (Northwestern Nebraska) Samantha Mills Follow this and additional works at: https://repository.stcloudstate.edu/crm_etds Part of the Archaeological Anthropology Commons Recommended Citation Mills, Samantha, "Paleoenvironment of the Late Eocene Chadronian-Age Whitehead Creek Locality (Northwestern Nebraska)" (2019). Culminating Projects in Cultural Resource Management. 28. https://repository.stcloudstate.edu/crm_etds/28 This Thesis is brought to you for free and open access by the Department of Anthropology at theRepository at St. Cloud State. It has been accepted for inclusion in Culminating Projects in Cultural Resource Management by an authorized administrator of theRepository at St. Cloud State. For more information, please contact [email protected]. Paleoenvironment of the Late Eocene Chadronian-Age Whitehead Creek Locality (Northwestern Nebraska) by Samantha M. Mills A Thesis Submitted to the Graduate Faculty of St. Cloud State University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Functional Morphology October, 2019 Thesis Committee: Matthew Tornow, Chairperson Mark Muñiz Bill Cook Tafline Arbor 2 Abstract Toward the end of the Middle Eocene (40-37mya), the environment started to decline on a global scale. It was becoming more arid, the tropical forests were disappearing from the northern latitudes, and there was an increase in seasonality. Research of the Chadronian (37- 33.7mya) in the Great Plains region of North America has documented the persistence of several mammalian taxa (e.g. primates) that are extinct in other parts of North America.
    [Show full text]
  • New Paleocene Skeletons and the Relationship of Plesiadapiforms to Crown-Clade Primates
    New Paleocene skeletons and the relationship of plesiadapiforms to crown-clade primates Jonathan I. Bloch*†, Mary T. Silcox‡, Doug M. Boyer§, and Eric J. Sargis¶ʈ *Florida Museum of Natural History, University of Florida, P. O. Box 117800, Gainesville, FL 32611; ‡Department of Anthropology, University of Winnipeg, 515 Portage Avenue, Winnipeg, MB, Canada, R3B 2E9; §Department of Anatomical Science, Stony Brook University, Stony Brook, NY 11794-8081; ¶Department of Anthropology, Yale University, P. O. Box 208277, New Haven, CT 06520; and ʈDivision of Vertebrate Zoology, Peabody Museum of Natural History, Yale University, New Haven, CT 06520 Communicated by Alan Walker, Pennsylvania State University, University Park, PA, November 30, 2006 (received for review December 6, 2005) Plesiadapiforms are central to studies of the origin and evolution preserved cranium of a paromomyid (10) seemed to independently of primates and other euarchontan mammals (tree shrews and support a plesiadapiform–dermopteran link, leading to the wide- flying lemurs). We report results from a comprehensive cladistic spread acceptance of this phylogenetic hypothesis. The evidence analysis using cranial, postcranial, and dental evidence including supporting this interpretation has been questioned (7, 9, 13, 15, 16, data from recently discovered Paleocene plesiadapiform skeletons 19, 20), but no previous study has evaluated the plesiadapiform– (Ignacius clarkforkensis sp. nov.; Dryomomys szalayi, gen. et sp. dermopteran link by using cranial, postcranial, and dental evidence,
    [Show full text]
  • Mammal and Plant Localities of the Fort Union, Willwood, and Iktman Formations, Southern Bighorn Basin* Wyoming
    Distribution and Stratigraphip Correlation of Upper:UB_ • Ju Paleocene and Lower Eocene Fossil Mammal and Plant Localities of the Fort Union, Willwood, and Iktman Formations, Southern Bighorn Basin* Wyoming U,S. GEOLOGICAL SURVEY PROFESS IONAL PAPER 1540 Cover. A member of the American Museum of Natural History 1896 expedition enter­ ing the badlands of the Willwood Formation on Dorsey Creek, Wyoming, near what is now U.S. Geological Survey fossil vertebrate locality D1691 (Wardel Reservoir quadran­ gle). View to the southwest. Photograph by Walter Granger, courtesy of the Department of Library Services, American Museum of Natural History, New York, negative no. 35957. DISTRIBUTION AND STRATIGRAPHIC CORRELATION OF UPPER PALEOCENE AND LOWER EOCENE FOSSIL MAMMAL AND PLANT LOCALITIES OF THE FORT UNION, WILLWOOD, AND TATMAN FORMATIONS, SOUTHERN BIGHORN BASIN, WYOMING Upper part of the Will wood Formation on East Ridge, Middle Fork of Fifteenmile Creek, southern Bighorn Basin, Wyoming. The Kirwin intrusive complex of the Absaroka Range is in the background. View to the west. Distribution and Stratigraphic Correlation of Upper Paleocene and Lower Eocene Fossil Mammal and Plant Localities of the Fort Union, Willwood, and Tatman Formations, Southern Bighorn Basin, Wyoming By Thomas M. Down, Kenneth D. Rose, Elwyn L. Simons, and Scott L. Wing U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1540 UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1994 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Robert M. Hirsch, Acting Director For sale by U.S. Geological Survey, Map Distribution Box 25286, MS 306, Federal Center Denver, CO 80225 Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S.
    [Show full text]
  • Geology and Vertebrate Paleontology of Western and Southern North America
    OF WESTERN AND SOUTHERN NORTH AMERICA OF WESTERN AND SOUTHERN NORTH PALEONTOLOGY GEOLOGY AND VERTEBRATE Geology and Vertebrate Paleontology of Western and Southern North America Edited By Xiaoming Wang and Lawrence G. Barnes Contributions in Honor of David P. Whistler WANG | BARNES 900 Exposition Boulevard Los Angeles, California 90007 Natural History Museum of Los Angeles County Science Series 41 May 28, 2008 Paleocene primates from the Goler Formation of the Mojave Desert in California Donald L. Lofgren,1 James G. Honey,2 Malcolm C. McKenna,2,{,2 Robert L. Zondervan,3 and Erin E. Smith3 ABSTRACT. Recent collecting efforts in the Goler Formation in California’s Mojave Desert have yielded new records of turtles, rays, lizards, crocodilians, and mammals, including the primates Paromomys depressidens Gidley, 1923; Ignacius frugivorus Matthew and Granger, 1921; Plesiadapis cf. P. anceps; and Plesiadapis cf. P. churchilli. The species of Plesiadapis Gervais, 1877, indicate that Member 4b of the Goler Formation is Tiffanian. In correlation with Tiffanian (Ti) lineage zones, Plesiadapis cf. P. anceps indicates that the Laudate Discovery Site and Edentulous Jaw Site are Ti2–Ti3 and Plesiadapis cf. P. churchilli indicates that Primate Gulch is Ti4. The presence of Paromomys Gidley, 1923, at the Laudate Discovery Site suggests that the Goler Formation occurrence is the youngest known for the genus. Fossils from Member 3 and the lower part of Member 4 indicate a possible marine influence as Goler Formation sediments accumulated. On the basis of these specimens and a previously documented occurrence of marine invertebrates in Member 4d, the Goler Basin probably was in close proximity to the ocean throughout much of its existence.
    [Show full text]
  • 8. Primate Evolution
    8. Primate Evolution Jonathan M. G. Perry, Ph.D., The Johns Hopkins University School of Medicine Stephanie L. Canington, B.A., The Johns Hopkins University School of Medicine Learning Objectives • Understand the major trends in primate evolution from the origin of primates to the origin of our own species • Learn about primate adaptations and how they characterize major primate groups • Discuss the kinds of evidence that anthropologists use to find out how extinct primates are related to each other and to living primates • Recognize how the changing geography and climate of Earth have influenced where and when primates have thrived or gone extinct The first fifty million years of primate evolution was a series of adaptive radiations leading to the diversification of the earliest lemurs, monkeys, and apes. The primate story begins in the canopy and understory of conifer-dominated forests, with our small, furtive ancestors subsisting at night, beneath the notice of day-active dinosaurs. From the archaic plesiadapiforms (archaic primates) to the earliest groups of true primates (euprimates), the origin of our own order is characterized by the struggle for new food sources and microhabitats in the arboreal setting. Climate change forced major extinctions as the northern continents became increasingly dry, cold, and seasonal and as tropical rainforests gave way to deciduous forests, woodlands, and eventually grasslands. Lemurs, lorises, and tarsiers—once diverse groups containing many species—became rare, except for lemurs in Madagascar where there were no anthropoid competitors and perhaps few predators. Meanwhile, anthropoids (monkeys and apes) emerged in the Old World, then dispersed across parts of the northern hemisphere, Africa, and ultimately South America.
    [Show full text]
  • Depositional History of the Chadron Formation in North Dakota
    Depositional History of the Chadron Formation in North Dakota by Clint A. Boyd1 and John R. Webster2 1North Dakota Geological Survey 2Geosciences, Minot State University REPORT OF INVESTIGATION NO. 120 NORTH DAKOTA GEOLOGICAL SURVEY Edward C. Murphy, State Geologist Lynn D. Helms, Director Dept. of Mineral Resources 2018 Table of Contents Abstract ........................................................................................................................................... v Acknowledgements ........................................................................................................................ vi Introduction ..................................................................................................................................... 1 Late Eocene Paleosols of North Dakota ......................................................................................... 3 Paleosols at White and Haystack Buttes (Stark County) ............................................................ 4 Description of Section 1 .......................................................................................................... 5 Description of Section 2 .......................................................................................................... 7 History of Paleosol Development ......................................................................................... 13 Interpretation ......................................................................................................................... 16
    [Show full text]
  • Foraging Behaviour of the Slender Loris (Loris Lydekkerianus Lydekkerianus): Implications for Theories of Primate Origins
    Journal of Human Evolution 49 (2005) 289e300 Foraging behaviour of the slender loris (Loris lydekkerianus lydekkerianus): implications for theories of primate origins K.A.I. Nekaris* Department of Anthropology, Washington University, Campus Box 1114, One Brookings Drive, St. Louis, MO 63110, USA Received 3 May 2004; accepted 18 April 2005 Abstract Members of the Order Primates are characterised by a wide overlap of visual fields or optic convergence. It has been proposed that exploitation of either insects or angiosperm products in the terminal branches of trees, and the corresponding complex, three-dimensional environment associated with these foraging strategies, account for visual convergence. Although slender lorises (Loris sp.) are the most visually convergent of all the primates, very little is known about their feeding ecology. This study, carried out over 10 ½ months in South India, examines the feeding behaviour of L. lydekkerianus lydekkerianus in relation to hypotheses regarding visual predation of insects. Of 1238 feeding observations, 96% were of animal prey. Lorises showed an equal and overwhelming preference for terminal and middle branch feeding, using the undergrowth and trunk rarely. The type of prey caught on terminal branches (Lepidoptera, Odonata, Homoptera) differed significantly from those caught on middle branches (Hymenoptera, Coleoptera). A two-handed catch accompanied by bipedal postures was used almost exclusively on terminal branches where mobile prey was caught, whereas the more common capture technique of one-handed grab was used more often on sturdy middle branches to obtain slow moving prey. Although prey was detected with senses other than vision, vision was the key sense used upon the final strike.
    [Show full text]
  • Colugos: Obscure Mammals Glide Into the Evolutionary Limelight Robert D Martin
    BioMed Central Minireview Colugos: obscure mammals glide into the evolutionary limelight Robert D Martin Address: Department of Anthropology, The Field Museum, Chicago, IL 60605-2496, USA. Email: [email protected] Published: 1 May 2008 Journal of Biology 2008, 7:13 (doi:10.1186/jbiol74) The electronic version of this article is the complete one and can be found online at http://jbiol.com/content/7/4/13 © 2008 BioMed Central Ltd Abstract Substantial molecular evidence indicates that tree-shrews, colugos and primates cluster together on the mammalian phylogenetic tree. Previously, a sister-group relationship between colugos and primates seemed likely. A new study of colugo chromosomes indicates instead an affinity between colugos and tree-shrews. Colugos, constituting the obscure and tiny order Dermop- shrews, tree-shrews, colugos, bats and primates. However, tera, are gliding mammals confined to evergreen tropical Simpson’s ensuing influential classification of mammals [1] rainforests of South-East Asia. There are two extant species, rejected this assemblage. Subsequently, prompted by Butler now placed in separate genera: Galeopterus variegatus [4], the superorder Archonta was progressively resuscitated, (Malayan colugo, formerly known as Cynocephalus variegatus) although most authors emphatically excluded elephant- and Cynocephalus volans (Philippine colugo). Their most shrews (for example [5,6]). A quite recent major classifi- obvious hallmark is a gliding membrane (patagium) cation of mammals [7] united tree-shrews, colugos, bats surrounding almost the entire body margin. Colugos are and primates in the grand order Archonta. also called ‘flying lemurs’, but - as Simpson aptly noted [1] - they “are not lemurs and cannot fly”. They differ from other This whole topic has been reinvigorated by molecular gliding mammals (certain rodents and marsupials) in that evidence indicating that tree-shrews, colugos and primates, the patagium also extends between the hind limbs and the at least, may be quite closely related.
    [Show full text]
  • NHS Dissertation4
    Patterns and Processes in the Dental Evolution of North American Plesiadapiforms and Euprimates from the Late Paleocene and Early Eocene DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Graduate School of The Ohio State University By Naava Hadassah Schottenstein, B.S. Graduate Program in Evolution, Ecology and Organismal Biology The Ohio State University 2020 Dissertation Committee: John P. Hunter, Advisor Mark Hubbe Bryan Carstens Debbie Guatelli-Steinberg Copyright by Naava Hadassah Schottenstein 2020 Abstract This dissertation explores the radiation of Primates during the Paleogene. The first radiation of Primates began with the plesiadapiforms near the Cretaceous-Paleogene boundary and the second radiation marked the introduction and diversification of euprimates at the beginning of the Eocene. Questions surrounding these radiations include their general patterns of evolution, rates of dental evolution, and potential influences of abiotic and biotic drivers. I explore these questions in euprimates by presenting a study of the Tetonius- Pseudotetonius primate lineage. Rates of evolution and the roles of neutral and adaptive processes across this lineage remain unclear. Linking Tetonius and Pseudotetonius are a series of stratigraphic and morphologic intermediates revealing possible functional and developmental reorganization within the dentition. Notable changes involved a reduction of the P3 and the P4 became a robust tall-cusped tooth. I test whether neutral evolution can explain the phenotypic differences in the lineage, and whether P4 lost developmental association with P3 and became integrated with the molars. I calculate the rate of evolutionary differentiation, based on the ratio between inter- and intra-species variation in length and width of the premolars and molars, between lineage segments and the entire lineage.
    [Show full text]
  • Virtual Endocast of Ignacius Graybullianus (Paromomyidae, Primates) and Brain Evolution in Early Primates
    Virtual endocast of Ignacius graybullianus (Paromomyidae, Primates) and brain evolution in early primates Mary T. Silcoxa,1, Claire K. Dalmynb, and Jonathan I. Blochc aDepartment of Anthropology, University of Winnipeg, 515 Portage Avenue, Winnipeg, MB R3B 2E9, Canada; bDepartment of Social Anthropology, York University, 4700 Keele Street, Toronto ON, M3J 1P3, Canada; cFlorida Museum of Natural History, University of Florida, P. O. Box 117800, Gainesville, FL 32611 Edited by Richard G. Klein, Stanford University, Stanford, CA, and approved May 14, 2009 (received for review November 28, 2008) Extant primates are distinctive among mammals in having rela- tively large brains. As stem primates, Paleogene plesiadapiforms provide direct information relevant to the earliest stages in the evolution of this characteristic. Here we describe a virtual endocast reconstructed from ultra high resolution X-ray computed tomog- raphy data for the paromomyid plesiadapiform Ignacius graybul- lianus (USNM 421608) from the early Eocene of Wyoming. This represents the most complete endocast known for a stem primate, allowing for an unprecedented study of both size and fine details of anatomy. Relative to fossil and extant euprimates, I. graybul- lianus had large olfactory lobes, but less caudal development of the cerebrum and a poorly demarcated temporal lobe, suggesting more emphasis on olfaction and a less well developed visual system. Although its brain was small compared to those of extant primates, the encephalization quotient of I. graybullianus is higher than that calculated for Paleocene Plesiadapis cookei and overlaps Fig. 1. Hypothesis of relationships for primates and other members of the lower portion of the range documented for fossil euprimates.
    [Show full text]
  • Vertical Support Use and Primate Origins Gabriel S
    www.nature.com/scientificreports OPEN Vertical support use and primate origins Gabriel S. Yapuncich 1, Henry J. Feng1, Rachel H. Dunn2, Erik R. Seifert 3 & Doug M. Boyer1 Adaptive scenarios of crown primate origins remain contentious due to uncertain order of acquisition Received: 1 May 2019 and functional signifcance of the clade’s diagnostic traits. A feature of the talus bone in the ankle, Accepted: 6 August 2019 known as the posterior trochlear shelf (PTS), is well-regarded as a derived crown primate trait, but Published: xx xx xxxx its adaptive signifcance has been obscured by poorly understood function. Here we propose a novel biomechanical function for the PTS and model the talus as a cam mechanism. By surveying a large sample of primates and their closest relatives, we demonstrate that the PTS is most strongly developed in extant taxa that habitually grasp vertical supports with strongly dorsifexed feet. Tali of the earliest fossils likely to represent crown primates exhibit more strongly developed PTS cam mechanisms than extant primates. As a cam, the PTS may increase grasping efciency in dorsifexed foot postures by increasing the path length of the fexor fbularis tendon, and thus improve the muscle’s ability to maintain fexed digits without increasing energetic demands. Comparisons are made to other passive digital fexion mechanisms suggested to exist in other vertebrates. These results provide robust anatomical evidence that the habitual vertical support use exerted a strong selective pressure during crown primate origins. Te talus is an important element for reconstructing positional behavior throughout primate evolution because the bone’s morphology correlates well with locomotor and postural behaviors of living euarchontans (the mam- malian clade including Primates, Scandentia, Dermoptera) and it is frequently preserved in fossil assemblages1–4.
    [Show full text]
  • Contextualising Primate Origins – an Ecomorphological Framework
    This is the accepted version of the following article: Soligo C, Smaers JB (2016). Contextualising primate origins – an ecomorphological framework. Journal of Anatomy 228: 608–629, which has been published in final form at [http://onlinelibrary.wiley.com/doi/10.1111/joa.12441/abstract]. This article may be used for non- commercial purposes in accordance with the Wiley Self-Archiving Policy [http://olabout.wiley.com/WileyCDA/Section/id-820227.html ]. Contextualising primate origins – An ecomorphological framework Authors: Christophe Soligo1 Jeroen B Smaers2 1 Department of Anthropology, University College London, 14 Taviton Street, London WC1 0BW, UK 2 Department of Anthropology, Stony Brook University, Stony Brook, New York 11794- 4364, USA Abstract Ecomorphology–the characterisation of the adaptive relationship between an organism’s morphology and its ecological role–has long been central to theories of the origin and early evolution of the primate order. This is exemplified by two of the most influential theories of primate origins: Matt Cartmill’s Visual Predation Hypothesis, and Bob Sussman’s Angiosperm Co-Evolution Hypothesis. However, the study of primate origins is constrained by the absence of data directly documenting the events under investigation, and has to rely instead on a fragmentary fossil record and the methodological assumptions inherent in phylogenetic comparative analyses of extant species. These constraints introduce particular challenges for inferring the ecomorphology of primate origins, since morphology and environmental context must first be inferred, before the relationship between the two can be considered. Fossils can be integrated in comparative analyses and observations of extant model species and laboratory experiments of form-function relationships are critical for the functional interpretation of the morphology of extinct species.
    [Show full text]