DOCSLIB.ORG

Adaptive Radiation of Multituberculate Mammals Before the Extinction of Dinosaurs

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Adaptive Radiation of Multituberculate Mammals Before the Extinction of Dinosaurs LETTER doi:10.1038/nature10880 Adaptive radiation of multituberculate mammals before the extinction of dinosaurs Gregory P. Wilson1, Alistair R. Evans2, Ian J. Corfe3, Peter D. Smits1,2, Mikael Fortelius3,4 & Jukka Jernvall3 TheCretaceous–Paleogene mass extinction approximately 66 million the ecological rise of angiosperms8 and suggests that the resources years ago is conventionally thought to have been a turning point in that were available to multituberculates were relatively unaffected mammalian evolution1,2. Prior to that event and for the first two- by the Cretaceous–Paleogene mass extinction. Taken together, our thirds of their evolutionary history, mammals were mostly confined results indicate that mammals were able to take advantage of new to roles as generalized, small-bodied, nocturnal insectivores3, ecological opportunities in the Mesozoic and that at least some of presumably under selection pressures from dinosaurs4. Release these opportunities persisted through the Cretaceous–Paleogene from these pressures, by extinction of non-avian dinosaurs at the mass extinction. Similar broad-scale ecomorphological inventories Cretaceous–Paleogene boundary, triggered ecological diversification of other radiations may help to constrain the possible causes of mass of mammals1,2. Although recent individual fossil discoveries have extinctions9,10. shown that some mammalian lineages diversified ecologically during Multituberculate mammals were a taxonomically rich3,11 and the Mesozoic era5, comprehensive ecological analyses of mammalian numerically abundant12 clade that had originated by the Middle groups crossing the Cretaceous–Paleogene boundary are lacking. Jurassic epoch (approximately 165 million years (Myr) ago) and went Such analyses are needed because diversification analyses of living extinct in the late Eocene (approximately 35 Myr ago)3,11. They were taxa6,7 allow only indirect inferencesof past ecosystems. Here weshow nearly globally distributed13 and had a distinctive dentition consisting that in arguably the most evolutionarily successful clade of Mesozoic of procumbent incisors, blade-like premolars, molars with longitudinal mammals, the Multituberculata, an adaptive radiation began at least rows of cusps (Fig. 1) and a predominantly posteriorly directed (palinal) 20 million years before the extinction of non-avian dinosaurs and chewing motion14,15. continued across the Cretaceous–Paleogene boundary. Disparity in Palaeontologists have agreed for a long time that the success of dental complexity, which relates to the range of diets, rose sharply in multituberculate mammals was at least partly related to their highly step with generic richness and disparity in body size. Moreover, derived dentition. Despite this, there is little consensus on the inter- maximum dental complexity and body size demonstrate an adaptive pretations of their feeding ecology, perhaps owing to the limitations of shift towards increased herbivory. This dietary expansion tracked previous approaches. For example, toothwear analysis is time intensive a Buccal Occlusal OPC p4 m2 m1 p3 p2 p1 Ctenacodon (155–148 Myr ago) OPC 84.375 b p4 m2 m1 Ptilodus (65–56 Myr ago) OPC 106.75 c m2 m1 p4 Cimolomys (84–66 Myr ago) OPC 202.125 d m2 m1 p4 1 mm + Taeniolabis (65–64 Myr ago) OPC 347.625 − Height Orientation Figure 1 | Cretaceous cimolomyid Cimolomys gracilis (c), Paleocene taeniolabidid Dental and dietary diversity in multituberculate mammals. a–d, Three- Taeniolabis taoensis (d). Surface orientation map of each three-dimensional dimensional buccal–occlusal and occlusal reconstructions of multituberculate reconstruction (colour wheel indicates orientation) for OPC measurements lower-right cheek tooth rows for GIS analysis: Late Jurassic plagiaulacid (shown by the number of coloured patches). Clumps that are smaller than three Ctenacodon serratus (a), Paleocene ptilodontoid Ptilodus kummae (b), Late grid points (black) are ignored. p, premolar; m, molar. Scale bars, 1 mm. 1Department of Biology, University of Washington, Seattle, Washington 98195-1800, USA. 2School of Biological Sciences, Monash University, Victoria 3800, Australia. 3Developmental Biology Program, Institute of Biotechnology, University of Helsinki, PO Box 56, FIN-00014, Helsinki, Finland. 4Department of Geosciences and Geography, University of Helsinki, PO Box 64, FIN-00014, Helsinki, Finland. 22 MARCH 2012 | VOL 483 | NATURE | 457 ©2012 Macmillan Publishers Limited. All rights reserved RESEARCH LETTER and requires high-quality preservation15, and multituberculates lack when comparing morphologically and phylogenetically divergent taxa. living descendants and this hampers comparative studies. Inter- Orientation patch count (OPC), a measure of dental complexity, was pretations of multituberculate feeding ecology therefore vary widely; calculated as the number of discrete surfaces on the cheek tooth row they have been proposed to be broad herbivores, frugivores, granivores, distinguished by differences in orientation (for example, north, root- and bark-eaters, egg-eaters, insectivores, carnivores and southwest; Fig. 1). Extant rodents, carnivorans and bats demonstrate omnivores15–17. a robust correlation between OPC and feeding ecology; OPC increases To obtain a robust and comprehensive view of multituberculate across the dietary spectrum from carnivores toomnivores to herbivores, ecomorphological diversity through time, we quantified dental com- despite many differences in specific tooth components, body size plexity in 41 genera using geographic information systems (GIS) and chewing mechanics among these taxa18,19. For a given clade, the analyses18 of three-dimensional crown surfaces of lower cheek teeth standard deviation of OPC is an effective proxy for the dietary diver- (Fig. 1; Supplementary Table 1). These analyses do not require cusp sification and divergence in feeding function: higher standard devi- and facet homologies to be established, which can be a challenging task ation means greater dental disparity and a broader range of diets. OPC thus offers promise as a powerful tool for quantifying overall tooth K–Pg shape and inferring diet in extinct taxa, such as multituberculates, that 80100120140160180 60 40 have highly derived dentitions with uncertain homology with living a mammals and imprecise functional analogy. 350 60 Among the earliest multituberculates, the ‘Plagiaulacida’ are a Dental-complexity disparity 300 paraphyletic assemblage of taxa with up to four simple blade-like 50 premolars and two multi-cusped molars (Fig. 1a). OPC analyses of 250 ‘plagiaulacids’ from the Late Jurassic through to the Early Cretaceous 40 (s.d.) 200 Herbivore epoch (from 156–100 Myr ago) show low and tightly constrained PD Omni 30 dental complexity (Fig. 2a; OPC, 84–125). Their OPC values corre- 150 Mean dental spond to carnivory and the low end of animal-dominated omnivory complexity (OPC) AD Omni 100 20 among extant mammals (for example, eating both insects and fruits). Carnivore Multituberculates in the early Late Cretaceous (100–84 Myr ago), 50 10 which include mostly basal members of the suborder Cimolodonta, Hypercarn 0 0 had a slightly higher mean OPC than did the ‘plagiaulacids’ but b retained the low standard deviation of OPC (Fig. 2a), indicating low 25 morphological disparity. A distinct break occurred 84–66 Myr ago, in the latest Cretaceous, when the mean OPC rose and peaked within the 20 Campanian (mean OPC, 145) and maximum OPC and disparity sharply increased as well (Fig. 2a; OPC, 70–230). Of the 17 taxa for 15 this interval, 5 have OPC values that are greater than 160 and 2 have OPC values that are greater than 200, corresponding to values for 10 plant-dominated omnivory and herbivory among extant mammals, (no. of genera) respectively (Fig. 2a). Taxonomic richness Taxonomic 5 Finally, in the early Paleocene (66–62 Myr ago) multituberculates maintained high OPC (mean OPC, 138) and disparity peaked (Fig. 2a; OPC, 70–348). The early Paleocene Taeniolabis from North 0 c 100 America (Fig. 1d) had the highest OPC among multituberculates (OPC, 348), which exceeded OPC values of extant herbivorous rodents and 2.5 carnivorans18. Of the 16 other early Paleocene taxa, 4 have OPC values 10 Body size disparity greater than 160 and 1 has an OPC value greater than 200 (Fig. 2a). 2.0 Mean OPC and disparity of OPC declined during the remainder of the 1 (s.d.) Paleocene and in the early Eocene (62–49 Myr ago). Ectypodus, the 1.5 only known genus from the middle to late Eocene (49–35 Myr ago), has 0.1 a low OPC (109), corresponding to the high end of the range for extant 1.0 mammalian carnivores. This sharp drop in dental ecomorphological Mean body size (kg) 0.01 0.5 Figure 2 | Temporal patterns of multituberculate dental complexity, taxonomic richness, body size and angiosperm ecological diversification. 0 d a, Dental complexity (measured by OPC) for 41 multituberculate genera (solid black lines) and estimated for 24 additional genera (dashed black lines; see Supplementary Information) with mean dental complexity (OPC; red line) and 40 16 Leaf-vein density disparity as standard deviations of OPC (blue line) in 5-Myr bins. Lengths of (mm per mm horizontal lines represent temporal ranges of taxa or uncertainties in ages of 30 12 fossil localities. Labels for dietary classes are positioned at the lower end of their range based on OPC values in modern mammals18. Green shaded area represents plant-dominated omnivory (PD omni) and herbivory. 20 8 2 ) b, Taxonomic richness is equal to the number
Load more

Recommended publications
  • Dome-Headed, Small-Brained Island Mammal from the Late Cretaceous of Romania
    Dome-headed, small-brained island mammal from the Late Cretaceous of Romania Zoltán Csiki-Savaa,1, Mátyás Vremirb, Jin Mengc, Stephen L. Brusatted, and Mark A. Norellc aLaboratory of Paleontology, Faculty of Geology and Geophysics, University of Bucharest, 010041 Bucharest, Romania; bDepartment of Natural Sciences, Transylvanian Museum Society, 400009 Cluj-Napoca, Romania; cDivision of Paleontology, American Museum of Natural History, New York, NY 10024; and dSchool of GeoSciences, Grant Institute, University of Edinburgh, EH9 3FE Edinburgh, United Kingdom Edited by Neil H. Shubin, The University of Chicago, Chicago, IL, and approved March 26, 2018 (received for review January 20, 2018) The island effect is a well-known evolutionary phenomenon, in describe the anatomy of kogaionids in detail, include them in a which island-dwelling species isolated in a resource-limited envi- comprehensive phylogenetic analysis, estimate their body sizes, ronment often modify their size, anatomy, and behaviors compared and present a reconstruction of their brain and sense organs. with mainland relatives. This has been well documented in modern This species exhibits several features that we interpret as re- and Cenozoic mammals, but it remains unclear whether older, more lated to its insular habitat, most notably a brain that is sub- primitive Mesozoic mammals responded in similar ways to island stantially reduced in size compared with close relatives and habitats. We describe a reasonably complete and well-preserved skeleton of a kogaionid, an enigmatic radiation of Cretaceous island- mainland contemporaries, demonstrating that some Mesozoic dwelling multituberculate mammals previously represented by frag- mammals were susceptible to the island effect like in more mentary fossils.
    [Show full text]
  • Enamel Ultrastructure of Multituberculate Mammals: an Investigation of Variability
    CO?JTRIBI!TIONS FROM THE MUSEUM OF PALEOK.1-OLOCiY THE UNIVERSITY OF MICHIGAN VOL. 27. NO. 1, p. 1-50 April I, 1985 ENAMEL ULTRASTRUCTURE OF MULTITUBERCULATE MAMMALS: AN INVESTIGATION OF VARIABILITY BY SANDRA J. CARLSON and DAVID W. KRAUSE MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN ANN ARBOR CONTRlBUTlONS FROM THE MUSEUM OF PALEON I OLOGY Philip D. Gingerich, Director Gerald R. Smith. Editor This series of contributions from the Museum of Paleontology is a medium for the publication of papers based chiefly upon the collection in the Museum. When the number of pages issued is sufficient to make a volume, a title page and a table of contents will be sent to libraries on the mailing list, and to individuals upon request. A list of the separate papers may also be obtained. Correspondence should be directed to the Museum of Paleontology, The University of Michigan, Ann Arbor, Michigan, 48109. VOLS. 11-XXVI. Parts of volumes may be obtained if available. Price lists available upon inquiry. CONTRIBUTIONS FROM THE MUSEUM OF PALEONTOLOGY THE UNIVERSITY OF MICHIGAN Vol . 27, no. 1, p. 1-50, pub1 ished April 1, 1985, Sandra J. Carlson and David W. Krause (Authors) ERRATA Page 11, Figure 4 caption, first line, should read "(1050X)," not "(750X)." ENAMEL ULTRASTRUCTURE OF MULTITUBERCULATE MAMMALS: AN INVESTIGATION OF VARIABILITY BY Sandra J. Carlsonl and David W. Krause' Abstract.-The nature and extent of enamel ultrastructural variation in mammals has not been thoroughly investigated. In this study we attempt to identify and evaluate the sources of variability in enamel ultrastructural patterns at a number of hierarchic levels within the extinct order Multituberculata.
    [Show full text]
  • AMERICAN MUSEUM NOVITATES Published by Number 267 Tnz AMERICAN Musumof Natural History April 30, 1927
    AMERICAN MUSEUM NOVITATES Published by Number 267 Tnz AMERICAN MUsuMOF NATuRAL HIsTORY April 30, 1927 56.9(117:78.6) MAMMALIAN FAUNA OF THE HELL CREEK FORMATION OF MONTANA BY GEORGE GAYLORD SIMPSON In 1907, Barnum Brown' announced the discovery, in the Hell Creek beds of Montana, of a small number of mammalian teeth. He then listed only Ptilodus sp., Meniscoessus conquistus Cope and Menisco8ssus sp., without description. In connection with recent work on the mammals of the Paskapoo formation of Alberta, this collection was referred to the writer for further study through the kindness of Mr. Brown and of Dr. W. D. Matthew, and a brief consideration of it is here presented. The material now available consists of two lots, one collected in 1906 by Brown and Kaisen, the other part of the Cameron Collection. The latter has no definite data as to locality save "the vicinity of Forsyth, Montana, and Snow Creek," and is thus from a region intermediate between the locality of the other Hell Creek specimens and that of the Niobrara County, Wyoming, Lance, but much nearer the former. Brown's collection is from near the head of Crooked Creek, in Dawson County, about eleven miles south of the Missouri River, Crooked Creek joining the latter about four miles northeast of the mouth of Hell Creek, along which are the type exposures of the formation. The mammals agree with the other palaeontological data in being of Lance age, although slightly different in detail from the Wyoming Lance fauna. The only localities now known for mammals of Lance age are the present ones, the classical Niobrara County Lance outcrops whence came all of Marsh's specimens, and an unknown point or points in South Dakota where Wortman found the types of Meniscoessus conquistus Cope and Thlzeodon padanicus Cope.
    [Show full text]
  • Multituberculate Mammals from the Wahweap
    MULTITUBERCULATE MAMMALS FROM THE WAHWEAP (CAMPANIAN, AQUILAN) AND KAIPAROWITS (CAMPANIAN, JUDITHIAN) FORMATIONS, WITHIN AND NEAR GRAND STAIRCASE-ESCALANTE NATIONAL MONUMENT, SOUTHERN UTAH Jeffrey G. Eaton Department of Geosciences Weber State University Ogden, UT 84408-2507 phone: (801) 626-6225 fax: (801) 626-7445 e-mail: [email protected] Cover photo by author: Powell Point in “The Blues,” the early Tertiary Claron Formation on the horizon and the Kaiparowits Formation in the foreground. ISBN 1-55791-665-9 Reference to any specific commercial product by trade name, trademark, or manufacturer does not constitute endorsement or recommendation by the Utah Geological Survey MISCELLANEOUS PUBLICATION 02-4 UTAH GEOLOGICAL SURVEY a division of 2002 Utah Department of Natural Resources STATE OF UTAH Michael O. Leavitt, Governor DEPARTMENT OF NATURAL RESOURCES Robert Morgan, Executive Director UTAH GEOLOGICAL SURVEY Richard G. Allis, Director UGS Board Member Representing Robert Robison (Chairman) ...................................................................................................... Minerals (Industrial) Geoffrey Bedell.............................................................................................................................. Minerals (Metals) Stephen Church .................................................................................................................... Minerals (Oil and Gas) E.H. Deedee O’Brien .......................................................................................................................
    [Show full text]
  • 71St Annual Meeting Society of Vertebrate Paleontology Paris Las Vegas Las Vegas, Nevada, USA November 2 – 5, 2011 SESSION CONCURRENT SESSION CONCURRENT
    ISSN 1937-2809 online Journal of Supplement to the November 2011 Vertebrate Paleontology Vertebrate Society of Vertebrate Paleontology Society of Vertebrate 71st Annual Meeting Paleontology Society of Vertebrate Las Vegas Paris Nevada, USA Las Vegas, November 2 – 5, 2011 Program and Abstracts Society of Vertebrate Paleontology 71st Annual Meeting Program and Abstracts COMMITTEE MEETING ROOM POSTER SESSION/ CONCURRENT CONCURRENT SESSION EXHIBITS SESSION COMMITTEE MEETING ROOMS AUCTION EVENT REGISTRATION, CONCURRENT MERCHANDISE SESSION LOUNGE, EDUCATION & OUTREACH SPEAKER READY COMMITTEE MEETING POSTER SESSION ROOM ROOM SOCIETY OF VERTEBRATE PALEONTOLOGY ABSTRACTS OF PAPERS SEVENTY-FIRST ANNUAL MEETING PARIS LAS VEGAS HOTEL LAS VEGAS, NV, USA NOVEMBER 2–5, 2011 HOST COMMITTEE Stephen Rowland, Co-Chair; Aubrey Bonde, Co-Chair; Joshua Bonde; David Elliott; Lee Hall; Jerry Harris; Andrew Milner; Eric Roberts EXECUTIVE COMMITTEE Philip Currie, President; Blaire Van Valkenburgh, Past President; Catherine Forster, Vice President; Christopher Bell, Secretary; Ted Vlamis, Treasurer; Julia Clarke, Member at Large; Kristina Curry Rogers, Member at Large; Lars Werdelin, Member at Large SYMPOSIUM CONVENORS Roger B.J. Benson, Richard J. Butler, Nadia B. Fröbisch, Hans C.E. Larsson, Mark A. Loewen, Philip D. Mannion, Jim I. Mead, Eric M. Roberts, Scott D. Sampson, Eric D. Scott, Kathleen Springer PROGRAM COMMITTEE Jonathan Bloch, Co-Chair; Anjali Goswami, Co-Chair; Jason Anderson; Paul Barrett; Brian Beatty; Kerin Claeson; Kristina Curry Rogers; Ted Daeschler; David Evans; David Fox; Nadia B. Fröbisch; Christian Kammerer; Johannes Müller; Emily Rayfield; William Sanders; Bruce Shockey; Mary Silcox; Michelle Stocker; Rebecca Terry November 2011—PROGRAM AND ABSTRACTS 1 Members and Friends of the Society of Vertebrate Paleontology, The Host Committee cordially welcomes you to the 71st Annual Meeting of the Society of Vertebrate Paleontology in Las Vegas.
    [Show full text]
  • Lhiwanj[Fuseum
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by American Museum of Natural History Scientific... >lhiwanJ[fuseum PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK 24, N.Y. NUMBER 2 2 26 AUGUST I7, I 965 First Evidence of Tooth Replacement in the Subclass Allotheria (Mammalia) BY FREDERICK S. SZALAY1 INTRODUCTION Multituberculates (the only known order of the subclass Allotheria) are abundantly represented in Mesozoic and Paleocene mammal locali- ties. Of the relatively large number of multituberculate mandibles and maxillae known up to the summer of 1963, not one showed a tooth in the process of replacement. Young specimens were known with less fully erupted teeth (Jepsen, 1940, p. 245; Clemens, 1963, p. 34), but it has not been possible before to demonstrate diphyodonty in multituberculates. With a now-standardized washing technique used for obtaining ver- tebrate microfossils (Hibbard, 1949; McKenna, 1962), a vertebrate paleontology field party of the American Museum of Natural History collected a large assemblage of vertebrate fossils during the summer of 1963. The collection was of approximately Torrejonian age from the eastern part of the Washakie Basin in southern Wyoming.2 Among the large number of multituberculates represented, a fragmentary left man- dible (A.M.N.H. No. 83003) is one of the two specimens described in the present paper that supply the first direct evidence of allotherian tooth replacement. The deciduous lower incisor is still present in the mandible, 1 Department of Zoology, Columbia University, New York, New York.
    [Show full text]
  • The Largest Fossil Rodent Andre´S Rinderknecht1 and R
    Proc. R. Soc. B doi:10.1098/rspb.2007.1645 Published online The largest fossil rodent Andre´s Rinderknecht1 and R. Ernesto Blanco2,* 1Museo Nacional de Historia Natural y Antropologı´a, Montevideo 11300, Uruguay 2Facultad de Ingenierı´a, Instituto de Fı´sica, Julio Herrera y Reissig 565, Montevideo 11300, Uruguay The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000 kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San Jose´ Formation, Uruguay, usually assigned to the Pliocene–Pleistocene (4–2 Myr ago), and the proposed palaeoenviron- ment where this rodent lived was characterized as an estuarine or deltaic system with forest communities. Keywords: giant rodents; Dinomyidae; megamammals 1. INTRODUCTION 3. HOLOTYPE The order Rodentia is the most abundant group of living MNHN 921 (figures 1 and 2; Museo Nacional de Historia mammals with nearly 40% of the total number of Natural y Antropologı´a, Montevideo, Uruguay): almost mammalian species recorded (McKenna & Bell 1997; complete skull without left zygomatic arch, right incisor, Wilson & Reeder 2005). In general, rodents have left M2 and right P4-M1. body masses smaller than 1 kg with few exceptions. The largest living rodent, the carpincho or capybara 4. AGE AND LOCALITY (Hydrochoerus hydrochaeris), which lives in the Neotro- Uruguay, Departament of San Jose´, coast of Rı´odeLa pical region of South America, has a body mass of Plata, ‘Kiyu´’ beach (348440 S–568500 W).
    [Show full text]
  • Craniodental Anatomy of a New Late Cretaceous Multituberculate Mammal from Udan Sayr, Mongolia
    University of Louisville ThinkIR: The University of Louisville's Institutional Repository Electronic Theses and Dissertations 8-2014 Craniodental anatomy of a new late cretaceous multituberculate mammal from Udan Sayr, Mongolia. Amir Subhash Sheth University of Louisville Follow this and additional works at: https://ir.library.louisville.edu/etd Part of the Anatomy Commons, and the Medical Neurobiology Commons Recommended Citation Sheth, Amir Subhash, "Craniodental anatomy of a new late cretaceous multituberculate mammal from Udan Sayr, Mongolia." (2014). Electronic Theses and Dissertations. Paper 1317. https://doi.org/10.18297/etd/1317 This Master's Thesis is brought to you for free and open access by ThinkIR: The nivU ersity of Louisville's Institutional Repository. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of ThinkIR: The nivU ersity of Louisville's Institutional Repository. This title appears here courtesy of the author, who has retained all other copyrights. For more information, please contact [email protected]. CRANIODENTAL ANATOMY OF A NEW LATE CRETACEOUS MULTITUBERCULATE MAMMAL FROM UDAN SAYR, MONGOLIA By Amir Subhash Sheth B.A., Centre College, 2010 A Thesis Submitted to the Faculty of the School of Medicine of the University of Louisville in Partial Fulfillment of the Requirements for the Degree of Master of Science Department of Anatomical Sciences and Neurobiology University of Louisville Louisville, Kentucky August 2014 CRANIODENTAL ANATOMY OF A NEW LATE CRETACEOUS MULTITUBERCULATE MAMMAL FROM UDAN SAYR, MONGOLIA By Amir Subhash Sheth B.A., Centre College, 2010 A Thesis Approved on July 18th, 2014 By the Following Thesis Committee: ________________________________ (Guillermo W.
    [Show full text]
  • Mammals from the Mesozoic of Mongolia
    Mammals from the Mesozoic of Mongolia Introduction and Simpson (1926) dcscrihed these as placental (eutherian) insectivores. 'l'he deltathcroids originally Mongolia produces one of the world's most extraordi- included with the insectivores, more recently have narily preserved assemblages of hlesozoic ma~nmals. t)een assigned to the Metatheria (Kielan-Jaworowska Unlike fossils at most Mesozoic sites, Inany of these and Nesov, 1990). For ahout 40 years these were the remains are skulls, and in some cases these are asso- only Mesozoic ~nanimalsknown from Mongolia. ciated with postcranial skeletons. Ry contrast, 'I'he next discoveries in Mongolia were made by the Mesozoic mammals at well-known sites in North Polish-Mongolian Palaeontological Expeditions America and other continents have produced less (1963-1971) initially led by Naydin Dovchin, then by complete material, usually incomplete jaws with den- Rinchen Barsbold on the Mongolian side, and Zofia titions, or isolated teeth. In addition to the rich Kielan-Jaworowska on the Polish side, Kazi~nierz samples of skulls and skeletons representing Late Koualski led the expedition in 1964. Late Cretaceous Cretaceous mam~nals,certain localities in Mongolia ma~nmalswere collected in three Gohi Desert regions: are also known for less well preserved, but important, Bayan Zag (Djadokhta Formation), Nenlegt and remains of Early Cretaceous mammals. The mammals Khulsan in the Nemegt Valley (Baruungoyot from hoth Early and Late Cretaceous intervals have Formation), and llcrmiin 'ISav, south-\vest of the increased our understanding of diversification and Neniegt Valley, in the Red beds of Hermiin 'rsav, morphologic variation in archaic mammals. which have heen regarded as a stratigraphic ecluivalent Potentially this new information has hearing on the of the Baruungoyot Formation (Gradzinslti r't crl., phylogenetic relationships among major branches of 1977).
    [Show full text]
  • Investigating Evolutionary Processes Using Ancient and Historical DNA of Rodent Species
    Investigating evolutionary processes using ancient and historical DNA of rodent species Thesis submitted for the degree of Doctor of Philosophy (PhD) University of London Royal Holloway University of London Egham, Surrey TW20 OEX Selina Brace November 2010 1 Declaration I, Selina Brace, declare that this thesis and the work presented in it is entirely my own. Where I have consulted the work of others, it is always clearly stated. Selina Brace Ian Barnes 2 “Why should we look to the past? ……Because there is nowhere else to look.” James Burke 3 Abstract The Late Quaternary has been a period of significant change for terrestrial mammals, including episodes of extinction, population sub-division and colonisation. Studying this period provides a means to improve understanding of evolutionary mechanisms, and to determine processes that have led to current distributions. For large mammals, recent work has demonstrated the utility of ancient DNA in understanding demographic change and phylogenetic relationships, largely through well-preserved specimens from permafrost and deep cave deposits. In contrast, much less ancient DNA work has been conducted on small mammals. This project focuses on the development of ancient mitochondrial DNA datasets to explore the utility of rodent ancient DNA analysis. Two studies in Europe investigate population change over millennial timescales. Arctic collared lemming (Dicrostonyx torquatus) specimens are chronologically sampled from a single cave locality, Trou Al’Wesse (Belgian Ardennes). Two end Pleistocene population extinction-recolonisation events are identified and correspond temporally with - localised disappearance of the woolly mammoth (Mammuthus primigenius). A second study examines postglacial histories of European water voles (Arvicola), revealing two temporally distinct colonisation events in the UK.
    [Show full text]
  • A Aardvark, 96 Abderites, 15, 162 Abderitidae, 11, 159, 200 Aboriginal, 15, 17 Adamantina, 79, 83 Africa, 79, 96, 116, 127, 130
    Index A Antarctic Circumpolar Current (ACC), 126, Aardvark, 96 188, 210 Abderites, 15, 162 Antarctic Counter Current, 104 Abderitidae, 11, 159, 200 Antarctic Peninsula, 12, 80, 83, 97, 109, Aboriginal, 15, 17 113–116, 165, 187, 216 Adamantina, 79, 83 Antarctic Region, 113, 133 Africa, 79, 96, 116, 127, 130, 141 Antarctodonas, 110 Afrotemperate Region, 133 Antechinus, 56 Afrothere, 96 Aonken Sea, 139 Afrotheria, 96, 97 Aptian, 79, 98, 129 Alamitan, 83, 90, 95, 141, 211 Aquatic, 130 Alchornea, 113 Araceae, 113 Alcidedorbignia, 94 Araucaria, 130 Alisphenoid, 10, 11 Arboreal, 6, 12, 38, 58–61, 64, 65 Allen, 80 Archaeodolops, 195 Allenian, 211 Archaeohyracidae, 143 Allotherian, 212 Archaeonothos, 109 Allqokirus, 95, 214 Arctodictis, 166 Alphadelphian, 214 Arecaceae, 113 Altiplano, 127 Argentina, 13, 17, 19, 22, 61, 80, 83, 95, 107, Altricial, 203 112, 116, 130, 135, 136, 138, 157 Ameghinichnus, 140 Argentodites, 212 Ameridelphia, 157, 165, 166, 186, 192, 195 Argyrolagidae, 13, 158, 196, 220 Ameridelphian, 91, 95, 106, 107, 110, 157, Argyrolagoidea, 13, 143, 195, 201, 220 166, 200, 213, 215, 216 Argyrolagus, 158, 220 Amphidolops, 195, 200 Arid diagonal, 135, 136, 138 Anachlysictis, 23, 161 Arminiheringia, 166, 194 Andean Range, 133 A1 scenario, 138 Andean Region, 127, 132, 133, 135, 136 Ascending ramus, 170 Andes, 12, 127 Asia, 6, 127, 156, 202 Andinodelphys, 95, 157, 159 Astragalar, 10 Angiosperm, 114, 115, 129, 190 Astrapotheria, 3 Angular process, 10, 11, 171, 175 Atacama Desert, 130, 133, 136 Animalivore, 47 Atlantic Forest, 61, 130 Animalivorous, 47 Atlantic Ocean, 137 Ankle bone, 96, 107 Atlantogenata, 97 Antarctica, 8, 12, 79, 98–100, 104, 109, 112, Australasia, 218 115, 116, 126, 127, 133, 135, 137, 210, 220 © Springer Science+Business Media Dordrecht 2016 227 F.J.
    [Show full text]
  • Vertebrate Paleontology of the Cretaceous/Tertiary Transition of Big Bend National Park, Texas (Lancian, Puercan, Mammalia, Dinosauria, Paleomagnetism)
    Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1986 Vertebrate Paleontology of the Cretaceous/Tertiary Transition of Big Bend National Park, Texas (Lancian, Puercan, Mammalia, Dinosauria, Paleomagnetism). Barbara R. Standhardt Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Standhardt, Barbara R., "Vertebrate Paleontology of the Cretaceous/Tertiary Transition of Big Bend National Park, Texas (Lancian, Puercan, Mammalia, Dinosauria, Paleomagnetism)." (1986). LSU Historical Dissertations and Theses. 4209. https://digitalcommons.lsu.edu/gradschool_disstheses/4209 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This reproduction was made from a copy of a manuscript sent to us for publication and microfilming. While the most advanced technology has been used to pho­ tograph and reproduce this manuscript, the quality of the reproduction is heavily dependent upon the quality of the material submitted. Pages in any manuscript may have indistinct print. In all cases the best available copy has been filmed. The following explanation of techniques is provided to help clarify notations which may appear on this reproduction. 1. Manuscripts may not always be complete. When it is not possible to obtain missing pages, a note appears to indicate this. 2. When copyrighted materials are removed from the manuscript, a note ap­ pears to indicate this. 3.
    [Show full text]