DOI: 10.1126/Science.282.5392.1298 , 1298 (1998); 282 Science Et Al
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JVP 26(3) September 2006—ABSTRACTS
Neoceti Symposium, Saturday 8:45 acid-prepared osteolepiforms Medoevia and Gogonasus has offered strong support for BODY SIZE AND CRYPTIC TROPHIC SEPARATION OF GENERALIZED Jarvik’s interpretation, but Eusthenopteron itself has not been reexamined in detail. PIERCE-FEEDING CETACEANS: THE ROLE OF FEEDING DIVERSITY DUR- Uncertainty has persisted about the relationship between the large endoskeletal “fenestra ING THE RISE OF THE NEOCETI endochoanalis” and the apparently much smaller choana, and about the occlusion of upper ADAM, Peter, Univ. of California, Los Angeles, Los Angeles, CA; JETT, Kristin, Univ. of and lower jaw fangs relative to the choana. California, Davis, Davis, CA; OLSON, Joshua, Univ. of California, Los Angeles, Los A CT scan investigation of a large skull of Eusthenopteron, carried out in collaboration Angeles, CA with University of Texas and Parc de Miguasha, offers an opportunity to image and digital- Marine mammals with homodont dentition and relatively little specialization of the feeding ly “dissect” a complete three-dimensional snout region. We find that a choana is indeed apparatus are often categorized as generalist eaters of squid and fish. However, analyses of present, somewhat narrower but otherwise similar to that described by Jarvik. It does not many modern ecosystems reveal the importance of body size in determining trophic parti- receive the anterior coronoid fang, which bites mesial to the edge of the dermopalatine and tioning and diversity among predators. We established relationships between body sizes of is received by a pit in that bone. The fenestra endochoanalis is partly floored by the vomer extant cetaceans and their prey in order to infer prey size and potential trophic separation of and the dermopalatine, restricting the choana to the lateral part of the fenestra. -
A Revised Taxonomy of the Iguanodont Dinosaur Genera and Species
ARTICLE IN PRESS + MODEL Cretaceous Research xx (2007) 1e25 www.elsevier.com/locate/CretRes A revised taxonomy of the iguanodont dinosaur genera and species Gregory S. Paul 3109 North Calvert Station, Side Apartment, Baltimore, MD 21218-3807, USA Received 20 April 2006; accepted in revised form 27 April 2007 Abstract Criteria for designating dinosaur genera are inconsistent; some very similar species are highly split at the generic level, other anatomically disparate species are united at the same rank. Since the mid-1800s the classic genus Iguanodon has become a taxonomic grab-bag containing species spanning most of the Early Cretaceous of the northern hemisphere. Recently the genus was radically redesignated when the type was shifted from nondiagnostic English Valanginian teeth to a complete skull and skeleton of the heavily built, semi-quadrupedal I. bernissartensis from much younger Belgian sediments, even though the latter is very different in form from the gracile skeletal remains described by Mantell. Currently, iguanodont remains from Europe are usually assigned to either robust I. bernissartensis or gracile I. atherfieldensis, regardless of lo- cation or stage. A stratigraphic analysis is combined with a character census that shows the European iguanodonts are markedly more morpho- logically divergent than other dinosaur genera, and some appear phylogenetically more derived than others. Two new genera and a new species have been or are named for the gracile iguanodonts of the Wealden Supergroup; strongly bipedal Mantellisaurus atherfieldensis Paul (2006. Turning the old into the new: a separate genus for the gracile iguanodont from the Wealden of England. In: Carpenter, K. (Ed.), Horns and Beaks: Ceratopsian and Ornithopod Dinosaurs. -
Implications for Predatory Dinosaur Macroecology and Ontogeny in Later Late Cretaceous Asiamerica
Canadian Journal of Earth Sciences Theropod Guild Structure and the Tyrannosaurid Niche Assimilation Hypothesis: Implications for Predatory Dinosaur Macroecology and Ontogeny in later Late Cretaceous Asiamerica Journal: Canadian Journal of Earth Sciences Manuscript ID cjes-2020-0174.R1 Manuscript Type: Article Date Submitted by the 04-Jan-2021 Author: Complete List of Authors: Holtz, Thomas; University of Maryland at College Park, Department of Geology; NationalDraft Museum of Natural History, Department of Geology Keyword: Dinosaur, Ontogeny, Theropod, Paleocology, Mesozoic, Tyrannosauridae Is the invited manuscript for consideration in a Special Tribute to Dale Russell Issue? : © The Author(s) or their Institution(s) Page 1 of 91 Canadian Journal of Earth Sciences 1 Theropod Guild Structure and the Tyrannosaurid Niche Assimilation Hypothesis: 2 Implications for Predatory Dinosaur Macroecology and Ontogeny in later Late Cretaceous 3 Asiamerica 4 5 6 Thomas R. Holtz, Jr. 7 8 Department of Geology, University of Maryland, College Park, MD 20742 USA 9 Department of Paleobiology, National Museum of Natural History, Washington, DC 20013 USA 10 Email address: [email protected] 11 ORCID: 0000-0002-2906-4900 Draft 12 13 Thomas R. Holtz, Jr. 14 Department of Geology 15 8000 Regents Drive 16 University of Maryland 17 College Park, MD 20742 18 USA 19 Phone: 1-301-405-4084 20 Fax: 1-301-314-9661 21 Email address: [email protected] 22 23 1 © The Author(s) or their Institution(s) Canadian Journal of Earth Sciences Page 2 of 91 24 ABSTRACT 25 Well-sampled dinosaur communities from the Jurassic through the early Late Cretaceous show 26 greater taxonomic diversity among larger (>50kg) theropod taxa than communities of the 27 Campano-Maastrichtian, particularly to those of eastern/central Asia and Laramidia. -
Phylogeny and Biogeography of Iguanodontian Dinosaurs, with Implications from Ontogeny and an Examination of the Function of the Fused Carpal-Digit I Complex
Phylogeny and Biogeography of Iguanodontian Dinosaurs, with Implications from Ontogeny and an Examination of the Function of the Fused Carpal-Digit I Complex By Karen E. Poole B.A. in Geology, May 2004, University of Pennsylvania M.A. in Earth and Planetary Sciences, August 2008, Washington University in St. Louis A Dissertation submitted to The Faculty of The Columbian College of Arts and Sciences of The George Washington University in partial fulfillment of the requirements for the degree of Doctor of Philosophy August 31, 2015 Dissertation Directed by Catherine Forster Professor of Biology The Columbian College of Arts and Sciences of The George Washington University certifies that Karen Poole has passed the Final Examination for the degree of Doctor of Philosophy as of August 10th, 2015. This is the final and approved form of the dissertation. Phylogeny and Biogeography of Iguanodontian Dinosaurs, with Implications from Ontogeny and an Examination of the Function of the Fused Carpal-Digit I Complex Karen E. Poole Dissertation Research Committee: Catherine A. Forster, Professor of Biology, Dissertation Director James M. Clark, Ronald Weintraub Professor of Biology, Committee Member R. Alexander Pyron, Robert F. Griggs Assistant Professor of Biology, Committee Member ii © Copyright 2015 by Karen Poole All rights reserved iii Dedication To Joseph Theis, for his unending support, and for always reminding me what matters most in life. To my parents, who have always encouraged me to pursue my dreams, even those they didn’t understand. iv Acknowledgements First, a heartfelt thank you is due to my advisor, Cathy Forster, for giving me free reign in this dissertation, but always providing valuable commentary on any piece of writing I sent her, no matter how messy. -
First Australian Spinosaur Dinosaur Had Global Distribution 15 June 2011
First Australian spinosaur dinosaur had global distribution 15 June 2011 Could the first Australian spinosaur dinosaur be a Spinosaur fossil. Credit: Jon Augier and Museum Victoria Baryonyx? New research has uncovered a fossil cervical vertebra that is nearly identical to a Baryonyx specimen at the Museum. This research suggests spinosaurs lived all over the world. They found that the fossil belonged to a young dinosaur in the meat-eating (theropod) group called spinosaurids. (PhysOrg.com) -- Could the first Australian "The new fossil is the first example of a spinosaurid spinosaur dinosaur be a Baryonyx? New research dinosaur from Australia," says Paul Barrett Natural has uncovered a fossil cervical vertebra that is History Museum dinosaur expert who led this study. nearly identical to a Baryonyx specimen at the "It is almost identical to the Natural History Museum. This research suggests spinosaurs lived Museum's own Baryonyx specimen from England." all over the world. The first spinosaur dinosaur from the Early Cretaceous (125-100 million years ago) of Australia has been uncovered and suggests these meat-eating dinosaurs lived all over the planet, scientists report in the journal Biology Letters today. Scientists from the Natural History Museum and University of Cambridge in the UK and the Museum Victoria and Monash University in Australia, identified a fossil cervical vertebra from a site in Victoria, Australia. 1 / 3 pattern. "They are showing that many of the dinosaurs that we used to think of as distinctively 'northern' or 'southern' in character were much more widespread during this particular period of Earth history. "We're starting to find more similarities than differences as we look at these recent finds in more detail." Supercontinental break up When dinosaurs roamed the planet during the Cretaceous Period, the Earth's surface looked very different to how it does today. -
Paleontological Discoveries in the Chorrillo Formation (Upper Campanian-Lower Maastrichtian, Upper Cretaceous), Santa Cruz Province, Patagonia, Argentina
Rev. Mus. Argentino Cienc. Nat., n.s. 21(2): 217-293, 2019 ISSN 1514-5158 (impresa) ISSN 1853-0400 (en línea) Paleontological discoveries in the Chorrillo Formation (upper Campanian-lower Maastrichtian, Upper Cretaceous), Santa Cruz Province, Patagonia, Argentina Fernando. E. NOVAS1,2, Federico. L. AGNOLIN1,2,3, Sebastián ROZADILLA1,2, Alexis M. ARANCIAGA-ROLANDO1,2, Federico BRISSON-EGLI1,2, Matias J. MOTTA1,2, Mauricio CERRONI1,2, Martín D. EZCURRA2,5, Agustín G. MARTINELLI2,5, Julia S. D´ANGELO1,2, Gerardo ALVAREZ-HERRERA1, Adriel R. GENTIL1,2, Sergio BOGAN3, Nicolás R. CHIMENTO1,2, Jordi A. GARCÍA-MARSÀ1,2, Gastón LO COCO1,2, Sergio E. MIQUEL2,4, Fátima F. BRITO4, Ezequiel I. VERA2,6, 7, Valeria S. PEREZ LOINAZE2,6 , Mariela S. FERNÁNDEZ8 & Leonardo SALGADO2,9 1 Laboratorio de Anatomía Comparada y Evolución de los Vertebrados. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Avenida Ángel Gallardo 470, Buenos Aires C1405DJR, Argentina - fernovas@yahoo. com.ar. 2 Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina. 3 Fundación de Historia Natural “Felix de Azara”, Universidad Maimonides, Hidalgo 775, C1405BDB Buenos Aires, Argentina. 4 Laboratorio de Malacología terrestre. División Invertebrados Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Avenida Ángel Gallardo 470, Buenos Aires C1405DJR, Argentina. 5 Sección Paleontología de Vertebrados. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Avenida Ángel Gallardo 470, Buenos Aires C1405DJR, Argentina. 6 División Paleobotánica. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Avenida Ángel Gallardo 470, Buenos Aires C1405DJR, Argentina. 7 Área de Paleontología. Departamento de Geología, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria (C1428EGA) Buenos Aires, Argentina. 8 Instituto de Investigaciones en Biodiversidad y Medioambiente (CONICET-INIBIOMA), Quintral 1250, 8400 San Carlos de Bariloche, Río Negro, Argentina. -
Cranial Anatomy of Allosaurus Jimmadseni, a New Species from the Lower Part of the Morrison Formation (Upper Jurassic) of Western North America
Cranial anatomy of Allosaurus jimmadseni, a new species from the lower part of the Morrison Formation (Upper Jurassic) of Western North America Daniel J. Chure1,2,* and Mark A. Loewen3,4,* 1 Dinosaur National Monument (retired), Jensen, UT, USA 2 Independent Researcher, Jensen, UT, USA 3 Natural History Museum of Utah, University of Utah, Salt Lake City, UT, USA 4 Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA * These authors contributed equally to this work. ABSTRACT Allosaurus is one of the best known theropod dinosaurs from the Jurassic and a crucial taxon in phylogenetic analyses. On the basis of an in-depth, firsthand study of the bulk of Allosaurus specimens housed in North American institutions, we describe here a new theropod dinosaur from the Upper Jurassic Morrison Formation of Western North America, Allosaurus jimmadseni sp. nov., based upon a remarkably complete articulated skeleton and skull and a second specimen with an articulated skull and associated skeleton. The present study also assigns several other specimens to this new species, Allosaurus jimmadseni, which is characterized by a number of autapomorphies present on the dermal skull roof and additional characters present in the postcrania. In particular, whereas the ventral margin of the jugal of Allosaurus fragilis has pronounced sigmoidal convexity, the ventral margin is virtually straight in Allosaurus jimmadseni. The paired nasals of Allosaurus jimmadseni possess bilateral, blade-like crests along the lateral margin, forming a pronounced nasolacrimal crest that is absent in Allosaurus fragilis. Submitted 20 July 2018 Accepted 31 August 2019 Subjects Paleontology, Taxonomy Published 24 January 2020 Keywords Allosaurus, Allosaurus jimmadseni, Dinosaur, Theropod, Morrison Formation, Jurassic, Corresponding author Cranial anatomy Mark A. -
A Century of Spinosaurs - a Review and Revision of the Spinosauridae
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Queen Mary Research Online A century of spinosaurs - a review and revision of the Spinosauridae with comments on their ecology HONE David William Elliott1, * HOLTZ Thomas Richard Jnr2 1 School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK 2 Department of Geology, University of Maryland, College Park, MD 20742 USA Abstract: The spinosaurids represent an enigmatic and highly unusual form of large tetanuran theropods that were first identified in 1915. A recent flurry of discoveries and taxonomic revisions of this important and interesting clade had added greatly to our knowledge, however, spinosaur body fossils are generally rare and most species are known from only limited skeletal remains. Their unusual anatomical adaptations to the skull, limbs and axial column all differ from other large theropods and point to an unusual ecological niche and a lifestyle intimately linked to water. Keywords: Theropoda, Megalosauroidea, Baryonychinae, Spinosaurinae, palaeoecology E-mail: [email protected] 1 Introduction The Spinosauridae is an enigmatic clade of large and carnivorous theropods from the Jurassic and Cretaceous that are known from both Gondwana and Laurasia (Holtz et al., 2004). Despite their wide temporal and geographic distribution, the clade is known primarily from teeth and the body fossil record is extremely limited (Bertin, 2010). As such, relatively little is known about this group of animals, although their unusual morphology with regard to skull shape, dentition, dorsal neural spines and other features mark them out as divergent from the essential bauplan of other non-tetanuran theropods (Fig 1). -
Second Discovery of a Spinosaurid Tooth from the Sebayashi Formation (Lower Cretaceous), Kanna Town, Gunma Prefecture, Japan
群馬県立自然史博物館研究報告(21):1-6,2017 1 Bull.Gunma Mus.Natu.Hist(. 21):1-6,2017 Original Article Second discovery of a spinosaurid tooth from the Sebayashi Formation (Lower Cretaceous), Kanna Town, Gunma Prefecture, Japan 1 2 2 KUBOTA Katsuhiro, TAKAKUWA Yuji and HASEGAWA Yoshikazu 1Kanna Dinosaur Center: 51-2, Kagahara, Kanna, Tano, Gunma 370-1602, Japan ([email protected]) 2Gunma Museum of Natural History: 1674-1 Kamikuroiwa, Tomioka, Gunma 370-2345, Japan ([email protected]; [email protected]) Abstract: A fragment of an isolated tooth is described from the Lower Cretaceous Sebayashi Formation of the Sanchu Group. Its crown is almost round in cross section and shows distinctive flutes. Between the flutes, there are longitudinal finely granular structures. The distinctive carinae have poorly defined serrations. It is probably assigned as a spinosaurid theropod dinosaur and is the second report from Japan. This spinosaurid tooth is found from the higher stratigraphic horizon of the same formation than the first. The occurrences of spinosaurids from two horizons suggest that spinosaurids might have habituated this area during the deposit of the Sebayashi Formation. The dental comparison between Asian and other spinosaurids suggests that Asian spinosaurids may have unique dental characteristics and be different from any known spinosaurids, although the phylogenetic relationships between Asian and other spinosaurids (baryonychines and spinosaurines) are unclear. Key words: Dinosaur, Spinosauridae, Sebayashi Formation, Gunma Prefecture, Kanna Town Introduction Macro-sized and longitudinal ornamentation on the crown is characteristic in spinosaurids and had been called as crest, flute, A fragmentary dinosaur tooth was collected in a fossil- ridge, and striation (Fig. -
A New Long-Necked Turtle, Laganemys Tenerensis (Pleurodira: Araripemydidae), from the Elrhaz Formation (Aptian–Albian) of Niger
Chapter 14 A New Long-Necked Turtle, Laganemys tenerensis (Pleurodira: Araripemydidae), from the Elrhaz Formation (Aptian–Albian) of Niger Paul C. Sereno and Sara J. ElShafie Abstract An articulated skull and postcranial skeleton of a Introduction pelomedusoid turtle, Laganemys tenerensis gen. et sp. nov., is described from the Lower Cretaceous (Aptian–Albian) Pleurodires are less speciose than cryptodires among living Elrhaz Formation in Niger. Laganemys has a proportion- turtles and are restricted in geographic range to freshwater ately long skull, which increases in depth anteriorly, from habitats in the southern hemisphere. Pleurodiran diversity, the occiput to the snout. The thin flat carapace and plastron habitats, and geographic range, however, were considerably are covered with fine sulcus-and-ridge texture. The carapace greater in the past and appear to have peaked from the has a deep nuchal embayment anteriorly, a small mesopl- Late Cretaceous (ca. 100 Mya) through the Paleocene (ca. astron laterally, and three median fenestrae. The cervical 55 Mya) (Gaffney et al. 2006). Preceding this rich record of series is nearly as long as the carapace with specialized pleurodiran diversity, however, is the first half of pleurodiran joints to enhance lateral flexion between cervicals 2 and 3 history. About 200 million years ago, pleurodires and cryp- and cervicals 6 and 7. The relatively long tail is composed todires diverged from a common casichelydian ancestor, and of at least 26 vertebrae. Forelimbs and hind limbs have long for the ensuing 100 Mya the pleurodire fossil record is and relatively straight unguals. Discovered in a fluvial comparatively thin (Gaffney et al. -
Structural Extremes in a Cretaceous Dinosaur Paul C
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by PubMed Central Structural Extremes in a Cretaceous Dinosaur Paul C. Sereno1*, Jeffrey A. Wilson2, Lawrence M. Witmer3, John A. Whitlock2, Abdoulaye Maga4, Oumarou Ide4, Timothy A. Rowe5 1 Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois, United States of America, 2 Museum of Paleontology and Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan, United States of America, 3 Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, Ohio, United States of America, 4 Institute for Human Science, University of Niamey, Niamey, Republic of Niger, 5 Jackson School of Geological Sciences, The University of Texas at Austin, Austin, Texas, United States of America Fossils of the Early Cretaceous dinosaur, Nigersaurus taqueti, document for the first time the cranial anatomy of a rebbachisaurid sauropod. Its extreme adaptations for herbivory at ground-level challenge current hypotheses regarding feeding function and feeding strategy among diplodocoids, the larger clade of sauropods that includes Nigersaurus. We used high resolution computed tomography, stereolithography, and standard molding and casting techniques to reassemble the extremely fragile skull. Computed tomography also allowed us to render the first endocast for a sauropod preserving portions of the olfactory bulbs, cerebrum and inner ear, the latter permitting us to establish habitual head posture. To elucidate evidence of tooth wear and tooth replacement rate, we used photographic-casting techniques and crown thin sections, respectively. To reconstruct its 9-meter postcranial skeleton, we combined and size-adjusted multiple partial skeletons. Finally, we used maximum parsimony algorithms on character data to obtain the best estimate of phylogenetic relationships among diplodocoid sauropods. -
Best Price for Cialis
RECENTLY REDISCOVERED BARYONYCHINE TEETH (DINOSAURIA: THEROPODA): NEW MORPHOLOGIC DATA, RANGE EXTENSION & SIMILARITY TO CERATOSAURUS FOWLER, D. W.: Museum of the Rockies, Bozeman, MT ABSTRACT Newly identified baryonychine teeth from the UK Wealden illustrate the morphologic variability and stratigraphic range of this taxon. Whilst common in the formations in which they occur, their distinctive fluted and finely serrated teeth are often misidentified as crocodilian, which are superficially similar in appearance. Fourteen teeth from mainland Weald collections of the British Museum of Natural History (some collected over 150 years ago, all stored with goniopholid specimens) demonstrate the presence of baryonychines in the Hauterivian and possibly Valanginian stages of the Early Cretaceous: the oldest record of this group. An unusual laterally compressed, posteriorly recurved, and fluted tooth from the Purbeck Limestone (Late Jurassic – earliest Cretaceous) may extend Fig. 1: Neovenator: two ‘typical’ theropod Fig. 2: a ‘typical’ Goniopholis tooth from the the range of baryonychines even further. Some specimens from the teeth, Isle of Wight (lateral view) Isle of Wight (lingual, posterior) Barremian Wessex Fm (Isle of Wight, UK) and older mainland deposits show both lingual and labial fluting, previously seen only in teeth from Spain. Spanish specimens can no longer be considered phylogenetically distinct based on this character. The fluted premaxillary and anterior dentary teeth of Ceratosaurus (and to a lesser extent, some other ceratosaurs e.g. Masiakasaurus) bear remarkable similarity to the fluted teeth of baryonychines. Whether this represents convergence or a real phylogenetic signal requires further analysis. However, isolated teeth identified as Ceratosaurus sp. from the Late Jurassic of Tendaguru, Tanzania, can no longer be assigned with confidence to this taxon and should be reassessed, especially as ceratosaur lateral teeth are unknown from these strata.