DOCSLIB.ORG

The Phylogenetic Position of Ambiortus: Comparison with Other Mesozoic Birds from Asia1 J

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Phylogenetic Position of Ambiortus: Comparison with Other Mesozoic Birds from Asia1 J ISSN 00310301, Paleontological Journal, 2013, Vol. 47, No. 11, pp. 1270–1281. © Pleiades Publishing, Ltd., 2013. The Phylogenetic Position of Ambiortus: Comparison with Other Mesozoic Birds from Asia1 J. K. O’Connora and N. V. Zelenkovb aKey Laboratory of Evolution and Systematics, Institute of Vertebrate Paleontology and Paleoanthropology, 142 Xizhimenwai Dajie, Beijing China 10044 bBorissiak Paleontological Institute, Russian Academy of Sciences, Profsoyuznaya ul. 123, Moscow, 117997 Russia email: [email protected], [email protected] Received August 6, 2012 Abstract—Since the last description of the ornithurine bird Ambiortus dementjevi from Mongolia, a wealth of Early Cretaceous birds have been discovered in China. Here we provide a detailed comparison of the anatomy of Ambiortus relative to other known Early Cretaceous ornithuromorphs from the Chinese Jehol Group and Xiagou Formation. We include new information on Ambiortus from a previously undescribed slab preserving part of the sternum. Ambiortus is superficially similar to Gansus yumenensis from the Aptian Xiagou Forma tion but shares more morphological features with Yixianornis grabaui (Ornithuromorpha: Songlingorni thidae) from the Jiufotang Formation of the Jehol Group. In general, the mosaic pattern of character distri bution among early ornithuromorph taxa does not reveal obvious relationships between taxa. Ambiortus was placed in a large phylogenetic analysis of Mesozoic birds, which confirms morphological observations and places Ambiortus in a polytomy with Yixianornis and Gansus. Keywords: Ornithuromorpha, Ambiortus, osteology, phylogeny, Early Cretaceous, Mongolia DOI: 10.1134/S0031030113110063 1 INTRODUCTION and articulated partial skeleton, preserving several cervi cal and thoracic vertebrae, and parts of the left thoracic Ambiortus dementjevi Kurochkin, 1982 was one of girdle and wing (specimen PIN, nos. 3790/271273; the first described Early Cretaceous ornithuromorph Figs. 1–3). The specimen preserves morphologies that birds. It comes from the Khurilt Ulaan Bulag locality were at first indicative of a fairly derived ornithuro of the Andaikhudag Formation (Hauterverian—Bar morph bird (e.g. curved scapula, bent acromion pro remian) in the Central Mongolian Altai (Kurochkin, cess, welldeveloped procoracoid process); the taxon 1982, 1985, 1999, 2000). Although dwarfed by the cur was originally considered a paleognathous bird, how rent Mesozoic bird collections in China, several other ever its position within Aves has shifted with the dis isolated Mesozoic bird taxa are also known from Mon covery of new taxa from the Jehol Biota. Most recently golia, including Apsaravis ukhaana Norell et Clarke, in a large cladistic analysis aimed towards Mesozoic 2001, Hollanda luceria Bell et al., 2010, Nanantius val birds as a whole, Ambiortus is resolved as a basal orni ifanovi Kurochkin, 1996, Elsornis keni Chiappe et al., thuromorph (O’Connor et al., 2011a). 2006, and several specimens of Gobipteryx minuta When Ambiortus was first described (Kurochkin, Elzanowski, 1974 (Elzanowski, 1974; Kurochkin, 1982), the Mesozoic record of fossil birds was 1996; Norell and Clarke, 2001; Chiappe et al., 2006; extremely sparse (Kurochkin, 1999). Gansus yumen Bell et al., 2010); these taxa span the ornithothoracine ensis Hou et Liu, 1984 was the first Mesozoic bird clade, making Mongolia one of the richest places for described from China (Hou and Liu, 1984). The holo Mesozoic birds in the world. Only enantiornithines type specimen was collected from the Early Creta (Nanantius, Gurilynia nessovi Kurochkin, 1999 and ceous Aptian Xiagou Formation in Gansu Province, Elsornis) and ornithuromorphs (Apsaravis, Hollanda, northwestern China (Hou and Liu, 1984); known Ambiortus) are known and, except for Ambiortus, these from only a single foot, this taxon was never compared taxa are all from the Late Cretaceous; no primitive with Ambiortus because of the lack of overlapping longtailed birds or basal pygostylians (e.g. Sapeorni material. Even a decade later, only a small handful of thiformes, Confuciusornithiformes), which form Early Cretaceous birds were known: primarily Con major components of the rich Early Cretaceous Jehol fuciusornis Hou et al., 1995 and a handful of fragmen avifauna, are known. The holotype and only known tary enantiornithines (Hou, 1997). Two ornithurines, specimen of Ambiortus dementjevi is a wellpreserved Chaoyangia beishanensis Hou et Zhang 1993 and Lia oningornis longidigitrus Hou, 1996, had also been 1 The article is published in the original. described (Hou et al., 1996), but the former lacked 1270 THE PHYLOGENETIC POSITION OF AMBIORTUS 1271 overlapping material with Ambiortus and the unusual scientific understanding of Mesozoic birds has morphology of the latter has recently proven to be changed rapidly over the past three decades, reexami enantiornithine (O’Connor, 2012). In the last major nation of incomplete materials in light of recent infor study to address Ambiortus, the taxon was compared to mation has the potential to reveal important new the Inner Mongolian bird Otogornis genghisi Dong, information (O’Connor et al., 2011b; O’Connor and 1993 from the Lower Cretaceous Yijinghouluo For Zhou, 2013). The holotype of Ambiortus dementjevi is mation (Kurochkin, 1999). This taxon, known from a one of the most complete Cretaceous ornithuromorph partial thoracic girdle and pair of wings, was originally specimens known from outside of China, yet it has not identified as an enantiornithine (Dong, 1993), been reexamined in light of the current taxonomic although when fully described was unassigned to a spe and morphological diversity. Here we redescribe cific clade (Hou, 1994). The comparative study, how Ambiortus, including previously unpublished data, and ever, concluded that both taxa were paleognathous compare it to recently described taxa, revealing new birds (Kurochkin, 1999). Although when comparative information regarding the phylogenetic placement of material was limited Ambiortus and Otogornis may have this taxon and the distribution of ornithuromorph lin born some superficial similarity (Kurochkin, 1999), a eages in Asia as a whole. relationship between these two taxa and their place Terminology in this paper primarily follows ment within Paleognathae is no longer supported; this Baumel and Witmer (1993); Latin is retained for mus is primarily due to lack of evidence and a greater cles (Baumel et al., 1993), while English equivalents understanding of Early Cretaceous ornithuromorph are used for osteological features. morphology. For example, Kurochkin (2000) noted Institutional abbreviations: CAGS, Chinese Acad that the presence of a Ushaped furcula and convex emy of Geological Sciences, Beijing, China; FRDC, scapular cotyla on the coracoid indicated that Ambior Fossil Research and Development Center, Third tus was a neornithine, features now known to be Geology and Mineral Resources Exploration Acad present in most basal ornithuromorphs. In light of emy, Gansu Provincial Bureau of Geo–Exploration more recent finds and a greater understanding and Mineral Development, Lanzhou, China; IVPP, of Enantiornithes, Otogornis is considered a member Institute of Vertebrate Paleontology and Paleoanthro of this large clade (Zhou et al., 2008), although the pology, Beijing, China; PIN, Borissiak Paleontologi taxon has been difficult to place in a phylogenetic con cal Institute of Russian Academy of Sciences, Mos text and its taxonomic position within Enantiornithes cow, Russia. is unstable (O’Connor, 2009). The short and robust shape of the humerus, absence of a procoracoid pro cess on the coracoid and straight scapula, all support SYSTEMATIC PALEONTOLOGY the enantiornithine affinity of this taxon (Zhou and Hou, 2002; O’Connor, 2009). Morphologies that sug AVES gested this taxon may be more advanced and in fact a ORNITHUROMORPHA paleognath bird (Kurochkin, 1999) are uncorrobo Genus Ambiortus Kurochkin, 1982 rated by the specimen; furthermore, the clearest char acters that define Paleognathae are from the skull, D i a g n o s i s. An ornithuromorph bird the size of which is preserved in neither Ambiortus nor Otogornis. extant teal Anas crecca, with the unique combination of the following features: a wide procoracoid process Record of the early radiation of Ornithuromorpha, perpendicular to the shaft; scapular blade long and the clade that includes modern birds (Neomithes), has thin; scapular acromion hooked; lateral trabecula of grown rapidly during the last decade (Chiappe, 2007; the sternum mediolaterally wide, with a concave O’Connor et al., 2010; Brocklehurst et al., 2012). medial margin and convex lateral margin so that the Where previously the global record was dominated by distal end of the process appears to curve medially; largely fragmentary specimens (e.g. Vorona berivotren ventral edge of the proximal end of the humerus sis Forster et al., 1996, Vegavis iaai Clarke et al., 2005) strongly developed and with a distinct tubercle on its and even in China known taxa were based on incom cranial surface; transverse groove is short, fossalike, plete and poorly preserved specimens (e.g. Chaoyan and runs dorsoventrally; pneumotricipital fossa of the gia, Gansus, Songlingornis linghensis Hou, 1997), humerus not developed; deltopectoral crest projected recent discoveries from the Early Cretaceous Jehol dorsally; bicipital crest distally abruptly ending Group and Xiagou Formation are largely complete (revised from Kurochkin, 2000). and wellpreserved (e.g. Yanornis
Load more

Recommended publications
  • Download Vol. 11, No. 3
    BULLETIN OF THE FLORIDA STATE MUSEUM BIOLOGICAL SCIENCES Volume 11 Number 3 CATALOGUE OF FOSSIL BIRDS: Part 3 (Ralliformes, Ichthyornithiformes, Charadriiformes) Pierce Brodkorb M,4 * . /853 0 UNIVERSITY OF FLORIDA Gainesville 1967 Numbers of the BULLETIN OF THE FLORIDA STATE MUSEUM are pub- lished at irregular intervals. Volumes contain about 800 pages and are not nec- essarily completed in any one calendar year. WALTER AuFFENBERC, Managing Editor OLIVER L. AUSTIN, JA, Editor Consultants for this issue. ~ HILDEGARDE HOWARD ALExANDER WErMORE Communications concerning purchase or exchange of the publication and all manuscripts should be addressed to the Managing Editor of the Bulletin, Florida State Museum, Seagle Building, Gainesville, Florida. 82601 Published June 12, 1967 Price for this issue $2.20 CATALOGUE OF FOSSIL BIRDS: Part 3 ( Ralliformes, Ichthyornithiformes, Charadriiformes) PIERCE BRODKORBl SYNOPSIS: The third installment of the Catalogue of Fossil Birds treats 84 families comprising the orders Ralliformes, Ichthyornithiformes, and Charadriiformes. The species included in this section number 866, of which 215 are paleospecies and 151 are neospecies. With the addenda of 14 paleospecies, the three parts now published treat 1,236 spDcies, of which 771 are paleospecies and 465 are living or recently extinct. The nominal order- Diatrymiformes is reduced in rank to a suborder of the Ralliformes, and several generally recognized families are reduced to subfamily status. These include Geranoididae and Eogruidae (to Gruidae); Bfontornithidae
    [Show full text]
  • Onetouch 4.0 Scanned Documents
    / Chapter 2 THE FOSSIL RECORD OF BIRDS Storrs L. Olson Department of Vertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC. I. Introduction 80 II. Archaeopteryx 85 III. Early Cretaceous Birds 87 IV. Hesperornithiformes 89 V. Ichthyornithiformes 91 VI. Other Mesozojc Birds 92 VII. Paleognathous Birds 96 A. The Problem of the Origins of Paleognathous Birds 96 B. The Fossil Record of Paleognathous Birds 104 VIII. The "Basal" Land Bird Assemblage 107 A. Opisthocomidae 109 B. Musophagidae 109 C. Cuculidae HO D. Falconidae HI E. Sagittariidae 112 F. Accipitridae 112 G. Pandionidae 114 H. Galliformes 114 1. Family Incertae Sedis Turnicidae 119 J. Columbiformes 119 K. Psittaciforines 120 L. Family Incertae Sedis Zygodactylidae 121 IX. The "Higher" Land Bird Assemblage 122 A. Coliiformes 124 B. Coraciiformes (Including Trogonidae and Galbulae) 124 C. Strigiformes 129 D. Caprimulgiformes 132 E. Apodiformes 134 F. Family Incertae Sedis Trochilidae 135 G. Order Incertae Sedis Bucerotiformes (Including Upupae) 136 H. Piciformes 138 I. Passeriformes 139 X. The Water Bird Assemblage 141 A. Gruiformes 142 B. Family Incertae Sedis Ardeidae 165 79 Avian Biology, Vol. Vlll ISBN 0-12-249408-3 80 STORES L. OLSON C. Family Incertae Sedis Podicipedidae 168 D. Charadriiformes 169 E. Anseriformes 186 F. Ciconiiformes 188 G. Pelecaniformes 192 H. Procellariiformes 208 I. Gaviiformes 212 J. Sphenisciformes 217 XI. Conclusion 217 References 218 I. Introduction Avian paleontology has long been a poor stepsister to its mammalian counterpart, a fact that may be attributed in some measure to an insufRcien- cy of qualified workers and to the absence in birds of heterodont teeth, on which the greater proportion of the fossil record of mammals is founded.
    [Show full text]
  • New Tyrannosaur from the Mid-Cretaceous of Uzbekistan Clarifies Evolution of Giant Body Sizes and Advanced Senses in Tyrant Dinosaurs
    Edinburgh Research Explorer New tyrannosaur from the mid-Cretaceous of Uzbekistan clarifies evolution of giant body sizes and advanced senses in tyrant dinosaurs Citation for published version: Brusatte, SL, Averianov, A, Sues, H, Muir, A & Butler, IB 2016, 'New tyrannosaur from the mid-Cretaceous of Uzbekistan clarifies evolution of giant body sizes and advanced senses in tyrant dinosaurs', Proceedings of the National Academy of Sciences, pp. 201600140. https://doi.org/10.1073/pnas.1600140113 Digital Object Identifier (DOI): 10.1073/pnas.1600140113 Link: Link to publication record in Edinburgh Research Explorer Document Version: Peer reviewed version Published In: Proceedings of the National Academy of Sciences General rights Copyright for the publications made accessible via the Edinburgh Research Explorer is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policy The University of Edinburgh has made every reasonable effort to ensure that Edinburgh Research Explorer content complies with UK legislation. If you believe that the public display of this file breaches copyright please contact [email protected] providing details, and we will remove access to the work immediately and investigate your claim. Download date: 04. Oct. 2021 Classification: Physical Sciences: Earth, Atmospheric, and Planetary Sciences; Biological Sciences: Evolution New tyrannosaur from the mid-Cretaceous of Uzbekistan clarifies evolution of giant body sizes and advanced senses in tyrant dinosaurs Stephen L. Brusattea,1, Alexander Averianovb,c, Hans-Dieter Suesd, Amy Muir1, Ian B. Butler1 aSchool of GeoSciences, University of Edinburgh, Edinburgh EH9 3FE, UK bZoological Institute, Russian Academy of Sciences, St.
    [Show full text]
  • Appendix A. Supplementary Material
    Appendix A. Supplementary material Comprehensive taxon sampling and vetted fossils help clarify the time tree of shorebirds (Aves, Charadriiformes) David Cernˇ y´ 1,* & Rossy Natale2 1Department of the Geophysical Sciences, University of Chicago, Chicago 60637, USA 2Department of Organismal Biology & Anatomy, University of Chicago, Chicago 60637, USA *Corresponding Author. Email: [email protected] Contents 1 Fossil Calibrations 2 1.1 Calibrations used . .2 1.2 Rejected calibrations . 22 2 Outgroup sequences 30 2.1 Neornithine outgroups . 33 2.2 Non-neornithine outgroups . 39 3 Supplementary Methods 72 4 Supplementary Figures and Tables 74 5 Image Credits 91 References 99 1 1 Fossil Calibrations 1.1 Calibrations used Calibration 1 Node calibrated. MRCA of Uria aalge and Uria lomvia. Fossil taxon. Uria lomvia (Linnaeus, 1758). Specimen. CASG 71892 (referred specimen; Olson, 2013), California Academy of Sciences, San Francisco, CA, USA. Lower bound. 2.58 Ma. Phylogenetic justification. As in Smith (2015). Age justification. The status of CASG 71892 as the oldest known record of either of the two spp. of Uria was recently confirmed by the review of Watanabe et al. (2016). The younger of the two marine transgressions at the Tolstoi Point corresponds to the Bigbendian transgression (Olson, 2013), which contains the Gauss-Matuyama magnetostratigraphic boundary (Kaufman and Brigham-Grette, 1993). Attempts to date this reversal have been recently reviewed by Ohno et al. (2012); Singer (2014), and Head (2019). In particular, Deino et al. (2006) were able to tightly bracket the age of the reversal using high-precision 40Ar/39Ar dating of two tuffs in normally and reversely magnetized lacustrine sediments from Kenya, obtaining a value of 2.589 ± 0.003 Ma.
    [Show full text]
  • Insight Into the Evolution of Avian Flight from a New Clade of Early
    J. Anat. (2006) 208, pp287–308 IBlackwnell Publishing sLtd ight into the evolution of avian flight from a new clade of Early Cretaceous ornithurines from China and the morphology of Yixianornis grabaui Julia A. Clarke,1 Zhonghe Zhou2 and Fucheng Zhang2 1Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA 2Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China Abstract In studies of the evolution of avian flight there has been a singular preoccupation with unravelling its origin. By con- trast, the complex changes in morphology that occurred between the earliest form of avian flapping flight and the emergence of the flight capabilities of extant birds remain comparatively little explored. Any such work has been limited by a comparative paucity of fossils illuminating bird evolution near the origin of the clade of extant (i.e. ‘modern’) birds (Aves). Here we recognize three species from the Early Cretaceous of China as comprising a new lineage of basal ornithurine birds. Ornithurae is a clade that includes, approximately, comparatively close relatives of crown clade Aves (extant birds) and that crown clade. The morphology of the best-preserved specimen from this newly recognized Asian diversity, the holotype specimen of Yixianornis grabaui Zhou and Zhang 2001, complete with finely preserved wing and tail feather impressions, is used to illustrate the new insights offered by recognition of this lineage. Hypotheses of avian morphological evolution and specifically proposed patterns of change in different avian locomotor modules after the origin of flight are impacted by recognition of the new lineage.
    [Show full text]
  • ZOOLOGY Exploring the Biodiversity of Colorado and Theworld
    CHAPTER 4 — ZOOLOGY Exploring the Biodiversity of Colorado and the World CHAPTER 4 ZOOLOGY Exploring the Biodiversity of Colorado and the World Jeffrey T. Stephenson, Before the Museum Paula E. Cushing, The first collections of specimens that make up what is now the Denver John R. Demboski, and Museum of Nature & Science were actually established well before the Frank-T. Krell founding of the institution in 1900, the selection of a board of trustees, or the construction of a building to house and exhibit the specimens. Edwin Carter (1830–1900) (Fig. 4.1) collected Colorado birds and mammals from the 1860s through the 1890s. Born in New York in 1830, Carter arrived in Colorado in 1859 hoping to make it rich in the goldfields, but he soon became interested in the region’s natural history. He learned hide tanning and, as his prospects for hitting the mother lode faded, he earned his living selling buckskin clothing that he handcrafted. Carter supplemented these earnings by mar- keting foodstuffs and other provisions to the growing population of successful and (mostly) unsuccessful prospectors flooding the region. His interest in nature turned to concern as he observed dwindling numbers of mammals and birds, owing largely to habitat destruction and overhunting. Period photographs of the area’s mining district show a landscape largely denuded of vegetation. By the 1870s, Carter noted that many animal species were becoming scarce. The state’s forests were being devastated, ranches and farms were replacing open prairie, and some species, including the last native bison in Colorado, were on the verge of extirpation or extinction.
    [Show full text]
  • Early Birding Book
    Early Birding in Dutchess County 1870 - 1950 Before Binoculars to Field Guides by Stan DeOrsey Published on behalf of The Ralph T. Waterman Bird Club, Inc. Poughkeepsie, New York 2016 Copyright © 2016 by Stan DeOrsey All rights reserved First printing July 2016 Digital version June 2018, with minor changes and new pages added at the end. Digital version July 2019, pages added at end. Cover images: Front: - Frank Chapman’s Birds of Eastern North America (1912 ed.) - LS Horton’s post card of his Long-eared Owl photograph (1906). - Rhinebeck Bird Club’s second Year Book with Crosby’s “Birds and Seasons” articles (1916). - Chester Reed’s Bird Guide, Land Birds East of the Rockies (1908 ed.) - 3x binoculars c.1910. Back: 1880 - first bird list for Dutchess County by Winfrid Stearns. 1891 - The Oölogist’s Journal published in Poughkeepsie by Fred Stack. 1900 - specimen tag for Canada Warbler from CC Young collection at Vassar College. 1915 - membership application for Rhinebeck Bird Club. 1921 - Maunsell Crosby’s county bird list from Rhinebeck Bird Club’s last Year Book. 1939 - specimen tag from Vassar Brothers Institute Museum. 1943 - May Census checklist, reading: Raymond Guernsey, Frank L. Gardner, Jr., Ruth Turner & AF [Allen Frost] (James Gardner); May 16, 1943, 3:30am - 9:30pm; Overcast & Cold all day; Thompson Pond, Cruger Island, Mt. Rutson, Vandenburg’s Cove, Poughkeepsie, Lake Walton, Noxon [in LaGrange], Sylvan Lake, Crouse’s Store [in Union Vale], Chestnut Ridge, Brickyard Swamp, Manchester, & Home via Red Oaks Mill. They counted 117 species, James Gardner, Frank’s brother, added 3 more.
    [Show full text]
  • Additional Specimen of Microraptor Provides Unique Evidence of Dinosaurs Preying on Birds
    Additional specimen of Microraptor provides unique evidence of dinosaurs preying on birds Jingmai O’Connor1, Zhonghe Zhou1, and Xing Xu Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China Contributed by Zhonghe Zhou, October 28, 2011 (sent for review September 13, 2011) Preserved indicators of diet are extremely rare in the fossil record; The vertebral column of this specimen is complete except for even more so is unequivocal direct evidence for predator–prey its proximal and distal ends; pleurocoels are absent from the relationships. Here, we report on a unique specimen of the small thoracic vertebrae, as in dromaeosaurids and basal birds. Poor nonavian theropod Microraptor gui from the Early Cretaceous preservation prevents clear observation of sutures; however, Jehol biota, China, which has the remains of an adult enantiorni- there does not appear to be any separation between the neural thine bird preserved in its abdomen, most likely not scavenged, arches and vertebral centra, or any other indicators that the but captured and consumed by the dinosaur. We provide direct specimen is a juvenile. The number of caudal vertebrae cannot evidence for the dietary preferences of Microraptor and a nonavian be estimated, but the elongate distal caudals are tightly bounded dinosaur feeding on a bird. Further, because Jehol enantiorni- by elongated zygapophyses, as in other dromaeosaurids. The rib thines were distinctly arboreal, in contrast to their cursorial orni- cage is nearly completely preserved; both right and left sides are thurine counterparts, this fossil suggests that Microraptor hunted visible ventrally closed by the articulated gastral basket.
    [Show full text]
  • Sind Vögel Dinosaurier? Eine Kritische Analyse Fossiler Befunde
    W+W Special Paper B-19-4 SIND VÖGEL DINOSAURIER? EINE KRITISCHE ANALYSE FOSSILER BEFUNDE Reinhard Junker August 2019 https://www.wort-und-wissen.de/artikel/sp/b-19-4_dinos-voegel.pdf Bild: Ein rekonstruiertes und künstlerisch dargestelltes Paar von Microraptor gui (Dromaeosauridae , Micro raptorinae). (durbed.deviantart.com, CC BY-SA 3.0) Sind Vögel Dinosaurier? Inhalt 1. Einleitung ...................................................................................... 3. kompakt ..................................................................................................... 4 Methodische Vorbemerkungen ............................................................................... 5 Zitate zu schrittweisem Erwerb von Vogelmerkmalen ...................................................... 6 2. Vogelmerkmale bei Theropoden: Vorläufer oder Konvergenzen ............................................................................... 9 2.1 Federtypen und Flugfähigkeit ..................................................................... 9 2.2 Zähne und Schnabel ................................................................................ 14 Zitate zu Konvergenzen bei Zahnverlust und Ausbildung eines Schnabels ................15 2.3 Gehirn und EQ ........................................................................................ 17 2.4 Furkula ..................................................................................................... 18 2.5 Gastralia, Rippenkorb, Brustbein ..............................................................
    [Show full text]
  • Paravian Phylogeny and the Dinosaur-Bird Transition: an Overview
    feart-06-00252 February 11, 2019 Time: 17:42 # 1 REVIEW published: 12 February 2019 doi: 10.3389/feart.2018.00252 Paravian Phylogeny and the Dinosaur-Bird Transition: An Overview Federico L. Agnolin1,2,3*, Matias J. Motta1,3, Federico Brissón Egli1,3, Gastón Lo Coco1,3 and Fernando E. Novas1,3 1 Laboratorio de Anatomía Comparada y Evolución de los Vertebrados, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Buenos Aires, Argentina, 2 Fundación de Historia Natural Félix de Azara, Universidad Maimónides, Buenos Aires, Argentina, 3 Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina Recent years witnessed the discovery of a great diversity of early birds as well as closely related non-avian theropods, which modified previous conceptions about the origin of birds and their flight. We here present a review of the taxonomic composition and main anatomical characteristics of those theropod families closely related with early birds, with the aim of analyzing and discussing the main competing hypotheses pertaining to avian origins. We reject the postulated troodontid affinities of anchiornithines, and the Edited by: dromaeosaurid affinities of microraptorians and unenlagiids, and instead place these Corwin Sullivan, University of Alberta, Canada groups as successive sister taxa to Avialae. Aiming to evaluate previous phylogenetic Reviewed by: analyses, we recoded unenlagiids in the traditional TWiG data matrix, which resulted Thomas Alexander Dececchi, in a large polytomy at the base of Pennaraptora. This indicates that the TWiG University of Pittsburgh, United States phylogenetic scheme needs a deep revision. Regarding character evolution, we found Spencer G. Lucas, New Mexico Museum of Natural that: (1) the presence of an ossified sternum goes hand in hand with that of ossified History & Science, United States uncinate processes; (2) the presence of foldable forelimbs in basal archosaurs indicates *Correspondence: widespread distribution of this trait among reptiles, contradicting previous proposals Federico L.
    [Show full text]
  • An Avian Quadrate from the Late Cretaceous Lance Formation of Wyoming
    Journal of Vertebrate Paleontology 20(4):712-719, December 2000 © 2000 by the Society of Vertebrate Paleontology AN AVIAN QUADRATE FROM THE LATE CRETACEOUS LANCE FORMATION OF WYOMING ANDRZEJ ELZANOWSKll, GREGORY S. PAUV, and THOMAS A. STIDHAM3 'Institute of Zoology, University of Wroclaw, Ul. Sienkiewicza 21, 50335 Wroclaw, Poland; 23109 N. Calvert St., Baltimore, Maryland 21218 U.S.A.; 3Department of Integrative Biology, University of California, Berkeley, California 94720 U.S.A. ABSTRACT-Based on an extensive survey of quadrate morphology in extant and fossil birds, a complete quadrate from the Maastrichtian Lance Formation has been assigned to a new genus of most probably odontognathous birds. The quadrate shares with that of the Odontognathae a rare configuration of the mandibular condyles and primitive avian traits, and with the Hesperomithidae a unique pterygoid articulation and a poorly defined (if any) division of the head. However, the quadrate differs from that of the Hesperomithidae by a hinge-like temporal articulation, a small size of the orbital process, a well-marked attachment for the medial (deep) layers of the protractor pterygoidei et quadrati muscle, and several other details. These differences, as well as the relatively small size of about 1.5-2.0 kg, suggest a feeding specialization different from that of Hesperomithidae. INTRODUCTION bination of its morphology, size, and both stratigraphic and geo- graphic occurrence effectively precludes its assignment to any The avian quadrate shows great taxonomic differences of a few fossil genera that are based on fragmentary material among the higher taxa of birds in the structure of its mandibular, without the quadrate.
    [Show full text]
  • STANDARDS for MANAGEMENT of the RECENT MAMMAL and BIRD COLLECTIONS at TEXAS TECH UNIVERSITY by AMY S. HALTER, B.S. a THESIS in M
    STANDARDS FOR MANAGEMENT OF THE RECENT MAMMAL AND BIRD COLLECTIONS AT TEXAS TECH UNIVERSITY by AMY S. HALTER, B.S. A THESIS IN MUSEUM SCIENCE Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of MASTER OF ARTS Approved August, 2001 © 2001 Amy S. Halter ALL RIGHTS RESERVED ACKNOWLEDGMENTS I wish to express my sincere gratitude to the members of my graduate committee. Dr. Robert J. Baker, chair, Dr. R. Richard Monk, co-chair, and Dr. Clyde Jones, for their support and guidance throughout my graduate career. Without their encouragement and enthusiasm, I would never have been able to complete this master's thesis. I thank Dr. Baker for his ideas and review of this thesis and for funding trips to museums similar to the NSRL to survey their collection management practices in preparation for writing this thesis. I especially thank Dr. Richard Monk for sharing with me his knowledge of collection management and museums, for his constant encouragement, and for his reviews of various drafts of this thesis. I thank Dr. Clyde Jones for sharing with me his extensive knowledge of museums and the natural sciences. I also wish to acknowledge the Curators and Collection Managers at the collections I visited who took the time to meet with me, answer my questions, and allow me to tour their collections. They are: Steve Cardiff, Donna Cardiff, and Mark Hafner of Louisiana State University; Thorvald Holmes, Jr. of the University of Kansas; Bill Gannon and Terry Yates of the University of New Mexico; Janet Braun of the University of Oklahoma; Robert Dowler and Marcia Revelez of Angelo State University; Fred Stangl of Midwestem State University; and George Baumgardner of Texas A&M University.
    [Show full text]