DOCSLIB.ORG

Premaxillae of the Extinct Megalonychid Sloths Acratocnus, Neocnus, and Megalonyx, and Their Phylogenetic Implication

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Premaxillae of the Extinct Megalonychid Sloths Acratocnus, Neocnus, and Megalonyx, and Their Phylogenetic Implication See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/282505841 Premaxillae of the Extinct Megalonychid Sloths Acratocnus, Neocnus, and Megalonyx, and their Phylogenetic Implication.... Article in Journal of Mammalian Evolution · September 2015 DOI: 10.1007/s10914-015-9308-7 CITATIONS READS 2 169 4 authors, including: Lauren Lyon H. Gregory McDonald East Tennessee State University BLM - The Bureau of Land Management Salt … 8 PUBLICATIONS 2 CITATIONS 127 PUBLICATIONS 2,512 CITATIONS SEE PROFILE SEE PROFILE Timothy J. Gaudin University of Tennessee at Chattanooga 61 PUBLICATIONS 1,618 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Digital endocasts of extinct and extant sloths View project Palaeobiology and functional anatomy of fossil Carnivora View project All content following this page was uploaded by Timothy J. Gaudin on 27 November 2015. The user has requested enhancement of the downloaded file. Premaxillae of the Extinct Megalonychid Sloths Acratocnus, Neocnus, and Megalonyx, and their Phylogenetic Implications (Mammalia, Xenarthra) Lauren M. Lyon, Chelsea Powell, H. Gregory McDonald & Timothy J. Gaudin Journal of Mammalian Evolution ISSN 1064-7554 J Mammal Evol DOI 10.1007/s10914-015-9308-7 1 23 Your article is protected by copyright and all rights are held exclusively by Springer Science +Business Media New York. This e-offprint is for personal use only and shall not be self- archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com”. 1 23 Author's personal copy J Mammal Evol DOI 10.1007/s10914-015-9308-7 ORIGINAL PAPER Premaxillae of the Extinct Megalonychid Sloths Acratocnus, Neocnus,andMegalonyx, and their Phylogenetic Implications (Mammalia, Xenarthra) Lauren M. Lyon1,2 & Chelsea Powell 1 & H. Gregory McDonald3 & Timothy J. Gaudin1 # Springer Science+Business Media New York 2015 Abstract In most folivorans, the premaxilla is loosely at- maxilla in two species of Megalonyx from North America, the tached to the maxilla, so that it is often missing in otherwise Blancan North American Land Mammal Age (NALMA) very well-preserved fossil skulls. Despite its infrequent pres- M. leptostomus and Rancholabrean NALMA M. jeffersonii. ervation in sloths, the premaxilla has been shown to have These species show a progressive reorientation of the premax- phylogenetically significant variation among the taxa that do illa within Megalonyx from a primitive horizontal element preserve the element. In the family Megalonychidae, the to a nearly vertical element, and some significant changes in premaxilla is known only in the early taxon Eucholoeops the anatomy of the incisive foramen. Morphological evidence (Santacrucian South American Land Mammal Age suggests that a broadened, plate-like premaxilla constitutes a [SALMA]), the extant two-toed sloth Choloepus,andthe synapomorphy for the entire clade Megalonychidae. North American Neogene taxon Megalonyx, the last described Furthermore, although Eucholoeops retains a short anterior only in an unpublished Master’s thesis. We report here process of the premaxilla like that of megatherioid sloths, this the discovery of the premaxilla in two genera of extinct process is lacking in the other megalonychids, suggesting that megalonychids, Neocnus and Acratocnus. These small bodied, the loss of this process may unite late Miocene to Recent semiarboreal megalonychid sloths are endemic to the islands megalonychids. of the Greater Antilles. Though the presence of sloths in the Caribbean dates at least to the late Oligocene, the best known Keywords Megalonychidae . Premaxilla . Neocnus . taxa derive from Pleistocene to Holocene cave deposits in Acratocnus . Megalonyx . Folivora Puerto Rico, Hispaniola, and Cuba. We also describe the pre- Introduction * Timothy J. Gaudin [email protected] The premaxilla is normally the anteriormost bone of the ven- Lauren M. Lyon tral rostrum in the mammalian skull. Among placentals it has [email protected] an extensive sutural attachment to the maxilla posteriorly, a H. Gregory McDonald dorsal attachment to the nasal and occasionally the frontal [email protected] bone, and often a small posterior contact with the vomer (Novacek 1993). It is typically tripartite, consisting of a body, a palatal process, and a dorsal process. The body, which is 1 Department of Biological & Environmental Sciences, University of Tennessee at Chattanooga, 615 McCallie Avenue, horizontal and lateral to the incisive foramen, forms the an- Chattanooga, TN 37403-2598, USA terolateral margin of the hard palate and houses the incisor 2 Department of Geosciences and Don Sunquist Center of Excellence teeth in most mammals, although these may be secondarily in Paleontology, East Tennessee State University, 325 Treasure Lane, lost as, for example, in some artiodactyls, sirenians, and in Johnson City, TN 37614, USA most xenarthrans (Ungar 2010). The palatal process is also 3 Museum Management Program, National Park Service, 1201 horizontal but lies medial to the incisive foramen. The dorsal Oakridge Drive, Fort Collins, CO 80525, USA process extends along the lateral margin of the external nares Author's personal copy J Mammal Evol (Evans and Christiansen 1979). In Folivora (=Tardigrada; investigate the systematic implications of premaxillary morphol- Fariña and Vizcaíno 2003), the incisors normally housed in ogy within Megalonychidae, and between Megalonychidae the body of the premaxilla have been lost, and the dorsal and other sloths. process is greatly reduced or absent (Engelmann 1985; Gaudin 2004). Thus, only the body and the palatal process remain, described herein as the lateral and medial rami of Material and Methods the premaxilla, respectively. This follows terminology long in use among sloth specialists, who refer to these portions of The present study was occasioned by the discovery of two iso- the bone as the medial and lateral Barms^ or Bbranches^ (see, lated premaxillary bones in museum collection drawers. Both e.g., Scott 1903–4; Stock 1925) of the premaxilla, formalized represent the first instance in which the bone has been recovered as the medial and lateral rami by De Iuliis (1994). There is for the relevant taxa, despite the fact that both taxa have been often an additional anterior process in sloths, defined as a thoroughly described in the literature, and are known from nu- distinct projection extending forward from the junction of merous well-preserved skulls (e.g., see Anthony 1926;Paula the lateral and medial rami (following De Iuliis 1994;De Couto 1967;MacPheeetal.2000; Gaudin 2011). The first pre- Iuliis et al. 2011). The xenarthran premaxilla typically forms maxilla was found among the extensive collection of sloth re- most, if not all, of the margin of the incisive foramen, which mains from Holocene cave deposits in Haiti housed at the Florida serves as the opening into the oral cavity for the nasopalatine Museum of Natural History, and derives from the small bodied duct (Wible and Gaudin 2004). megalonychid sloth, Neocnus comes (UF 248501, right side In most folivoran species, the premaxilla is not sutured to the only; Fig. 2). The second was found at the American Museum maxilla. This means that the premaxilla is rarely found articu- of Natural History, and pertains to the mid-sized late Pleistocene/ lated with fossil skulls (indeed, the premaxilla is frequently Holocene megalonychid sloth from Puerto Rico, Acratocnus missing in museum specimens of the extant three-toed sloth odontrigonus (AMNH 17716, left side only; Fig. 3). Figures 2 Bradypus), and its morphology is poorly known. There are and 3 show the bones in dorsal and ventral view, and include exceptions, e.g., the Mio-Pliocene nothrothere, Thalassocnus reconstructions showing the positions the bones would occupy (McDonald and Muizon 2002). In the megathere in the intact skull. One of us (HGM) had also noted the preser- Megatherium and the scelidothere, Scelidotherium, the lateral vation of the premaxilla in specimens of the late Pliocene ramus is often fused to the skull and the premaxilla is (Blancan NALMA) North American species Megalonyx commonly preserved, though curiously this is not the case in leptostomus (UF 216900, right side only; Fig. 4) from the their respective close Neotropical relatives, Eremotherium and Florida Museum of Natural History, and the late Pleistocene Catonyx. Despite its infrequent preservation, De Iuliis (1994) (Rancholabrean NALMA) North American species Megalonyx has shown that the bone exhibits significant variation among jeffersonii from the Florida Museum of Natural History living and fossil sloths that can be systematically informative. (UF 213841), the Idaho Museum of Natural History (IMNH In the present study, descriptions of the morphology of the 23034), and the Denver Museum of Nature and Science premaxilla are provided in six species of megalonychid sloths: (DMNS EVP. 65000). Descriptions of M. jeffersonii are based Choloepus
Load more

Recommended publications
  • Ancient Mitogenomes Shed Light on the Evolutionary History And
    Ancient Mitogenomes Shed Light on the Evolutionary History and Biogeography of Sloths Frédéric Delsuc, Melanie Kuch, Gillian Gibb, Emil Karpinski, Dirk Hackenberger, Paul Szpak, Jorge Martinez, Jim Mead, H. Gregory Mcdonald, Ross Macphee, et al. To cite this version: Frédéric Delsuc, Melanie Kuch, Gillian Gibb, Emil Karpinski, Dirk Hackenberger, et al.. Ancient Mitogenomes Shed Light on the Evolutionary History and Biogeography of Sloths. Current Biology - CB, Elsevier, 2019. hal-02326384 HAL Id: hal-02326384 https://hal.archives-ouvertes.fr/hal-02326384 Submitted on 22 Oct 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 1 Ancient Mitogenomes Shed Light on the Evolutionary 2 History and Biogeography of Sloths 3 Frédéric Delsuc,1,13,*, Melanie Kuch,2 Gillian C. Gibb,1,3, Emil Karpinski,2,4 Dirk 4 Hackenberger,2 Paul Szpak,5 Jorge G. Martínez,6 Jim I. Mead,7,8 H. Gregory 5 McDonald,9 Ross D. E. MacPhee,10 Guillaume Billet,11 Lionel Hautier,1,12 and 6 Hendrik N. Poinar2,* 7 Author list footnotes 8 1Institut des Sciences de l’Evolution de Montpellier
    [Show full text]
  • Research, Society and Development, V. 9, N. 7, E316973951, 2020 (CC by 4.0) | ISSN 2525-3409 | DOI
    Research, Society and Development, v. 9, n. 7, e316973951, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i7.3951 Mendes, MS, Zanesco, T, Melki, LB, Rangel, CC, Ferreira, BM, Lima, CV, Oliveira, MA & Candeiro, CRA. (2020). Eremotherium (Xenarthra, Mammalia) das coleções da Universidade Federal de Goiás, Brasil. Research, Society and Development, 9(7): 1-18, e316973951. Eremotherium (Xenarthra, Mammalia) das coleções da Universidade Federal de Goiás, Brasil Eremotherium (Xenarthra, Mammalia) from the collections of the Universidade Federal de Goiás, Brazil Eremotherium (Xenarthra, Mammalia) de las colecciones de la Universidade Federal de Goiás, Brasil Recebido: 25/04/2020 | Revisado: 01/05/2020 | Aceito: 07/05/2020 | Publicado: 14/05/2020 Millena Silva Mendes ORCID: http://orcid.org/0000-0003-3894-7331 Universidade Federal de Goiás, Brasil E-mail: [email protected] Tábata Zanesco ORCID: http://orcid.org/0000-0002-6850-629 Universidade Federal do Rio de Janeiro, Brasil E-mail: [email protected] Luiza Bomfim Melki ORCID: http://orcid.org/0000-0003-0862-8946 Universidade Federal do Rio de Janeiro, Brasil E-mail: [email protected] Caio César Rangel ORCID: http://orcid.org/0000-0001-8707-9441 Universidade Federal de Uberlândia, Brasil E-mail: [email protected] Bruno Martins Ferreira ORCID: http://orcid.org/0000-0001-9498-9179 Universidade Federal de Goiás, Brasil E-mail: [email protected] Cláudia Valéria Lima ORCID: http://orcid.org/0000-0001-9991-2541 1 Research, Society and Development,
    [Show full text]
  • Uma Perspectiva Macroecológica Sobre O Risco De Extinção Em Mamíferos
    Universidade Federal de Goiás Instituto de Ciências Biológicas Programa de Pós-graduação em Ecologia e Evolução Uma Perspectiva Macroecológica sobre o Risco de Extinção em Mamíferos VINÍCIUS SILVA REIS Goiânia 2019 VINÍCIUS SILVA REIS Uma Perspectiva Macroecológica sobre o Risco de Extinção em Mamíferos Tese apresentada ao Programa de Pós-graduação em Ecologia e Evolução do Departamento de Ecologia do Instituto de Ciências Biológicas da Universidade Federal de Goiás como requisito parcial para a obtenção do título de Doutor em Ecologia e Evolução. Orientador: Profº Drº Matheus de Souza Lima- Ribeiro Co-orientadora: Profª Drª Levi Carina Terribile Goiânia 2019 DEDI CATÓRIA Ao meu pai Wilson e à minha mãe Iris por sempre acreditarem em mim. “Esper o que próxima vez que eu te veja, você s eja um novo homem com uma vasta gama de novas experiências e aventuras. Não he site, nem se permita dar desculpas. Apenas vá e faça. Vá e faça. Você ficará muito, muito feliz por ter feito”. Trecho da carta escrita por Christopher McCandless a Ron Franz contida em Into the Wild de Jon Krakauer (Livre tradução) . AGRADECIMENTOS Eis que a aventura do doutoramento esteve bem longe de ser um caminho solitário. Não poderia ter sido um caminho tão feliz se eu não tivesse encontrado pessoas que me ensinaram desde método científico até como se bebe cerveja de verdade. São aos que estiveram comigo desde sempre, aos que permaneceram comigo e às novas amizades que eu construí quando me mudei pra Goiás que quero agradecer por terem me apoiado no nascimento desta tese: À minha família, em especial meu pai Wilson, minha mãe Iris e minha irmã Flora, por me apoiarem e me incentivarem em cada conquista diária.
    [Show full text]
  • Michael O. Woodburne1,* Alberto L. Cione2,**, and Eduardo P. Tonni2,***
    Woodburne, M.O.; Cione, A.L.; and Tonni, E.P., 2006, Central American provincialism and the 73 Great American Biotic Interchange, in Carranza-Castañeda, Óscar, and Lindsay, E.H., eds., Ad- vances in late Tertiary vertebrate paleontology in Mexico and the Great American Biotic In- terchange: Universidad Nacional Autónoma de México, Instituto de Geología and Centro de Geociencias, Publicación Especial 4, p. 73–101. CENTRAL AMERICAN PROVINCIALISM AND THE GREAT AMERICAN BIOTIC INTERCHANGE Michael O. Woodburne1,* Alberto L. Cione2,**, and Eduardo P. Tonni2,*** ABSTRACT The age and phyletic context of mammals that dispersed between North and South America during the past 9 m.y. is summarized. The presence of a Central American province of cladogenesis and faunal differentiation is explored. One apparent aspect of such a province is to delay dispersals of some taxa northward from Mexico into the continental United States, largely during the Blancan. Examples are recognized among the various xenar- thrans, and cervid artiodactyls. Whereas the concept of a Central American province has been mentioned in past investigations it is upgraded here. Paratoceras (protoceratid artio- dactyl) and rhynchotheriine proboscideans provide perhaps the most compelling examples of Central American cladogenesis (late Arikareean to early Barstovian and Hemphillian to Rancholabrean, respectively), but this category includes Hemphillian sigmodontine rodents, and perhaps a variety of carnivores and ungulates from Honduras in the medial Miocene, as well as peccaries and equids from Mexico. For South America, Mexican canids and hy- drochoerid rodents may have had an earlier development in Mexico. Remarkably, the first South American immigrants to Mexico (after the Miocene heralds; the xenarthrans Plaina and Glossotherium) apparently dispersed northward at the same time as the first Holarctic taxa dispersed to South America (sigmodontine rodents and the tayassuid artiodactyls).
    [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]
  • Taphonomy and Significance of Jefferson's Ground Sloth (Xenarthra: Megalonychidae) from Utah
    Western North American Naturalist Volume 61 Number 1 Article 9 1-29-2001 Taphonomy and significance of Jefferson's ground sloth (Xenarthra: Megalonychidae) from Utah H. Gregory McDonald Hagerman Fossil Beds National Monument, Hagerman, Idaho Wade E. Miller Thomas H. Morris Follow this and additional works at: https://scholarsarchive.byu.edu/wnan Recommended Citation McDonald, H. Gregory; Miller, Wade E.; and Morris, Thomas H. (2001) "Taphonomy and significance of Jefferson's ground sloth (Xenarthra: Megalonychidae) from Utah," Western North American Naturalist: Vol. 61 : No. 1 , Article 9. Available at: https://scholarsarchive.byu.edu/wnan/vol61/iss1/9 This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Western North American Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. Western North American Naturalist 61(1), © 2001, pp. 64–77 TAPHONOMY AND SIGNIFICANCE OF JEFFERSON’S GROUND SLOTH (XENARTHRA: MEGALONYCHIDAE) FROM UTAH H. Gregory McDonald1, Wade E. Miller2, and Thomas H. Morris2 ABSTRACT.—While a variety of mammalian megafauna have been recovered from sediments associated with Lake Bonneville, Utah, sloths have been notably rare. Three species of ground sloth, Megalonyx jeffersonii, Paramylodon har- lani, and Nothrotheriops shastensis, are known from the western United States during the Pleistocene. Yet all 3 are rare in the Great Basin, and the few existing records are from localities on the basin margin. The recent discovery of a partial skeleton of Megalonyx jeffersonii at Point-of-the-Mountain, Salt Lake County, Utah, fits this pattern and adds to our understanding of the distribution and ecology of this extinct species.
    [Show full text]
  • Xenarthra: Megatheriidae) Were in Chile?: New Evidences from the Bahía Inglesa Formation, with a Reappraisal of Their Biochronological Affinities
    Andean Geology ISSN: 0718-7092 ISSN: 0718-7106 [email protected] Servicio Nacional de Geología y Minería Chile How many species of the aquatic sloth Thalassocnus (Xenarthra: Megatheriidae) were in Chile?: new evidences from the Bahía Inglesa Formation, with a reappraisal of their biochronological affinities Peralta-Prat, Javiera; Solórzano, Andrés How many species of the aquatic sloth Thalassocnus (Xenarthra: Megatheriidae) were in Chile?: new evidences from the Bahía Inglesa Formation, with a reappraisal of their biochronological affinities Andean Geology, vol. 46, no. 3, 2019 Servicio Nacional de Geología y Minería, Chile Available in: https://www.redalyc.org/articulo.oa?id=173961656010 This work is licensed under Creative Commons Attribution 3.0 International. PDF generated from XML JATS4R by Redalyc Project academic non-profit, developed under the open access initiative Javiera Peralta-Prat, et al. How many species of the aquatic sloth Thalassocnus (Xenarthra: Megath... Paleontological Note How many species of the aquatic sloth alassocnus (Xenarthra: Megatheriidae) were in Chile?: new evidences from the Bahía Inglesa Formation, with a reappraisal of their biochronological affinities ¿Cuántas especies del perezoso acuático alassocnus (Xenarthra: Megatheriidae) existieron en Chile?: nuevas evidencias de la Formación Bahía Inglesa, con una revisión de sus afinidades biocronológicas. Javiera Peralta-Prat 1 Redalyc: https://www.redalyc.org/articulo.oa? Universidad de Concepción, Chile id=173961656010 [email protected] Andrés Solórzano *2 Universidad de Concepción, Chile [email protected] Received: 13 July 2018 Accepted: 27 November 2018 Published: 04 February 2019 Abstract: e aquatic sloth, alassocnus, is one of the most intriguing lineage of mammal known from the southern pacific coast of South America during the late Neogene.
    [Show full text]
  • Paleogeography of the Caribbean Region: Implications for Cenozoic Biogeography
    PALEOGEOGRAPHY OF THE CARIBBEAN REGION: IMPLICATIONS FOR CENOZOIC BIOGEOGRAPHY MANUEL A. ITURRALDE-VINENT Research Associate, Department of Mammalogy American Museum of Natural History Curator, Geology and Paleontology Group Museo Nacional de Historia Natural Obispo #61, Plaza de Armas, CH-10100, Cuba R.D.E. MA~PHEE Chairman and Curator, Department of Mammalogy American Museum of Natural History BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY Number 238, 95 pages, 22 figures, 2 appendices Issued April 28, 1999 Price: $10.60 a copy Copyright O American Museum of Natural History 1999 ISSN 0003-0090 CONTENTS Abstract ....................................................................... 3 Resumen ....................................................................... 4 Resumo ........................................................................ 5 Introduction .................................................................... 6 Acknowledgments ............................................................ 8 Abbreviations ................................................................ 9 Statement of Problem and Methods ............................................... 9 Paleogeography of the Caribbean Region: Evidence and Analysis .................. 18 Early Middle Jurassic to Late Eocene Paleogeography .......................... 18 Latest Eocene to Middle Miocene Paleogeography .............................. 27 Eocene-Oligocene Transition (35±33 Ma) .................................... 27 Late Oligocene (27±25 Ma) ...............................................
    [Show full text]
  • The Southernmost Occurrence of the Aquatic Sloth Thalassocnus (Mammalia, Tardigrada) in Two New Pliocene Localities in Chile
    THE SOUTHERNMOST OCCURRENCE OF THE AQUATIC SLOTH THALASSOCNUS (MAMMALIA, TARDIGRADA) IN TWO NEW PLIOCENE LOCALITIES IN CHILE Por:De Los Arcos, S (De Los Arcos, Saleta)[ 1 ] ; Partarrieu, D (Partarrieu, Diego)[ 1,2 ] ; Carrillo- Briceno, J (Carrillo-Briceno, Jorge)[ 3 ] ; Amson, E(Amson, Eli)[ 3,4,5 ] AMEGHINIANA Volumen: 54 Número: 4 Páginas: 351-369 DOI: 10.5710/AMGH.29.12.2016.3004 Fecha de publicación: AUG 2017 Tipo de documento:Article Ver impacto de la revista Resumen Thalassocnus is a sloth (Mammalia, Tardigrada) adapted to an aquatic lifestyle. It was first described from the Neogene deposits of the Pisco Formation of Peru, from where most of the specimens come. The genus is represented by five species ranging from the late Miocene to the late Pliocene, occupying successive stratigraphic levels. Morpho-functional studies of the cranial and postcranial skeleton of Thalassocnus have demonstrated the progressive adaptation of these sloths to a marine environment, establishing gradual differences from from the geologically oldest to the youngest species of the genus. The first records of Thalassocnus outside the Pisco Formation have been referred to the Neogene Bahia Inglesa Formation, in northern Chile, where older species were recovered. In this paper, we describe materials from two new Pliocene localities in Chile: the Coquimbo and the Horcon formations, in northern and central Chile, respectively. The Coquimbo Formation material was collected from the Lomas del Sauce locality and consists of a partial skeleton of a single individual. Detailed comparisons of the elements with diagnostic features enabled the referral of this specimen to T. carolomartini. The material from the Horcon Formation was collected from the Playa La Luna locality and consists of an isolated phalanx, which is attributed to one of the species of Thalassocnus younger than T.
    [Show full text]
  • La Brea and Beyond: the Paleontology of Asphalt-Preserved Biotas
    La Brea and Beyond: The Paleontology of Asphalt-Preserved Biotas Edited by John M. Harris Natural History Museum of Los Angeles County Science Series 42 September 15, 2015 Cover Illustration: Pit 91 in 1915 An asphaltic bone mass in Pit 91 was discovered and exposed by the Los Angeles County Museum of History, Science and Art in the summer of 1915. The Los Angeles County Museum of Natural History resumed excavation at this site in 1969. Retrieval of the “microfossils” from the asphaltic matrix has yielded a wealth of insect, mollusk, and plant remains, more than doubling the number of species recovered by earlier excavations. Today, the current excavation site is 900 square feet in extent, yielding fossils that range in age from about 15,000 to about 42,000 radiocarbon years. Natural History Museum of Los Angeles County Archives, RLB 347. LA BREA AND BEYOND: THE PALEONTOLOGY OF ASPHALT-PRESERVED BIOTAS Edited By John M. Harris NO. 42 SCIENCE SERIES NATURAL HISTORY MUSEUM OF LOS ANGELES COUNTY SCIENTIFIC PUBLICATIONS COMMITTEE Luis M. Chiappe, Vice President for Research and Collections John M. Harris, Committee Chairman Joel W. Martin Gregory Pauly Christine Thacker Xiaoming Wang K. Victoria Brown, Managing Editor Go Online to www.nhm.org/scholarlypublications for open access to volumes of Science Series and Contributions in Science. Natural History Museum of Los Angeles County Los Angeles, California 90007 ISSN 1-891276-27-1 Published on September 15, 2015 Printed at Allen Press, Inc., Lawrence, Kansas PREFACE Rancho La Brea was a Mexican land grant Basin during the Late Pleistocene—sagebrush located to the west of El Pueblo de Nuestra scrub dotted with groves of oak and juniper with Sen˜ora la Reina de los A´ ngeles del Rı´ode riparian woodland along the major stream courses Porciu´ncula, now better known as downtown and with chaparral vegetation on the surrounding Los Angeles.
    [Show full text]
  • Redalyc.VERTEBRATE PALEONTOLOGY in CENTRAL
    Red de Revistas Científicas de América Latina, el Caribe, España y Portugal Sistema de Información Científica Lucas, Spencer G. VERTEBRATE PALEONTOLOGY IN CENTRAL AMERICA: 30 YEARS OF PROGRESS Revista Geológica de América Central, , 2014, pp. 139-155 Universidad de Costa Rica San José, Costa Rica Available in: http://www.redalyc.org/articulo.oa?id=45433963013 Revista Geológica de América Central, ISSN (Printed Version): 0256-7024 [email protected] Universidad de Costa Rica Costa Rica How to cite Complete issue More information about this article Journal's homepage www.redalyc.org Non-Profit Academic Project, developed under the Open Acces Initiative Revista Geológica de América Central, Número Especial 2014: 30 Aniversario: 139-155, 2014 DOI: 10.15517/rgac.v0i0.16576 ISSN: 0256-7024 VERTEBRATE PALEONTOLOGY IN CENTRAL AMERICA: 30 YEARS OF PROGRESS PALEONTOLOGÍA DE VERTEBRADOS EN AMÉRICA CENTRAL: 30 AÑOS DE PROGRESO Spencer G. Lucas New Mexico Museum of Natural History and Science, 1801 Mountain Road N. W., Albuquerque, New Mexico 87104 USA [email protected] (Recibido: 7/08/2014; aceptado: 10/10/2014) ABSTRACT: Vertebrate paleontology began in Central America in 1858 with the first published records, but the last 30 years have seen remarkable advances. These advances range from new localities, to new taxa to new analyses of diverse data. Central American vertebrate fossils represent all of the major taxonomic groups of vertebrates—fishes, amphibians, reptiles (especially turtles), birds and mammals (mostly xenarthrans, carnivores and ungulates)—but co- verage is very uneven, with many groups (especially small vertebrates) poorly represented. The vertebrate fossils of Central America have long played an important role in understanding the great American biotic interchange.
    [Show full text]
  • A Well-Preserved Ground Sloth (Megalonyx) Cranium from Turin, Monona County, Iowa
    Proceedings of the Iowa Academy of Science Volume 90 Number Article 6 1983 A Well-Preserved Ground Sloth (Megalonyx) Cranium from Turin, Monona County, Iowa H. Gregory McDonald Idaho State University Duane C. Anderson University of Iowa Let us know how access to this document benefits ouy Copyright ©1983 Iowa Academy of Science, Inc. Follow this and additional works at: https://scholarworks.uni.edu/pias Recommended Citation McDonald, H. Gregory and Anderson, Duane C. (1983) "A Well-Preserved Ground Sloth (Megalonyx) Cranium from Turin, Monona County, Iowa," Proceedings of the Iowa Academy of Science, 90(4), 134-140. Available at: https://scholarworks.uni.edu/pias/vol90/iss4/6 This Research is brought to you for free and open access by the Iowa Academy of Science at UNI ScholarWorks. It has been accepted for inclusion in Proceedings of the Iowa Academy of Science by an authorized editor of UNI ScholarWorks. For more information, please contact [email protected]. McDonald and Anderson: A Well-Preserved Ground Sloth (Megalonyx) Cranium from Turin, Mon Proc. Iowa Acad. Sci. 90(4): 134-140. 1983 A Well-Preserved Ground Sloth (Mega/onyx) Cranium from Turin, Monona County, Iowa H. GREGORY McDONALD 1 Idaho Museum of Natural History, Idaho State University, Pocatello, Idaho 83209 DUANE C. ANDERSON State Archaeologist, Univeristy of Iowa, Iowa City, Iowa 52242 A well-preserved cranium of a large Pleistocene ground sloth (Mega/onyx jeffersonii) is described in detail and compared with six other North American Mega/onyx crania. Although the morphology of the Iowa specimen compares favorably with all others, the descending flange of the zygomatic arch is unusual in that it is sharply deflected to the posterior.
    [Show full text]