DOCSLIB.ORG

May 17, 2019 Mary Gates Hall

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
May 17, 2019 Mary Gates Hall May 17, 2019 Mary Gates Hall POSTER SESSION 2 POSTER SESSION 2 MGH 206, Easel 169 MGH 206, Easel 168 1:00 PM to 2:30 PM 1:00 PM to 2:30 PM Characterizing the Growth Patterns of Thickened A New Drepanosauromorph Species from the Chinle Synapsid Skulls via Osteohistology Formation of Petrified Forest National Park, Arizona Lianna Molas Marilao, Senior, English (Creative Writing), Gabriel Stedman (Gabe) Goncalves, Senior, Earth & Space Biology (Ecology, Evolution & Conservation) Sciences (Biology) Mentor: Christian Sidor, Biology Mentor: Christian Sidor, Biology Mentor: Zoe Kulik, Biology Mentor: Brandon Peecook, Field Museum Cranial elaboration, in the form of domes, horns, and bony Drepanosauromorpha is an extinct group of reptiles bosses, has evolved multiple times in vertebrate history, in- known from the Middle to Late Triassic (237–212 MA). cluding in non-mammalian synapsids, the extinct ancestors The clade currently includes seven genera (Avicranium, of mammals. The lack of similarly thickened skulls in living Dolabrosaurus, Drepanosaurus, Hypuronector, Kyrgzsaurus, animals has meant that very little can be inferred about how Megalancosaurus, and Vallesaurus) that are known from fos- these features developed or why they evolved. Here we use sils collected in Europe (Italy, UK), North America (Ari- comparative bone histology to describe the microanatomy of zona, New Mexico, New Jersey), and Asia (Kyrgyzstan). Oudenodon, a 255-million-year-old synapsid with distinctive The first described drepanosauromorph, Drepanosaurus un- nasal bosses. We compared thin-sections from the thickened guicaudatus, was based on a flattened holotype preserv- portions of Oudenodon to the non-thickened skull of its rel- ing most of a complete skeleton. Subsequently described ative, Diictodon, in order to better understand how cranial drepanosauromorphs display the following diagnostic fea- elaboration developed in synapsids. We took thin sections tures: the length of the chevrons (ventral spines below from the thick nasal bosses as well as non-thickened regions the tail vertebrae) is substantially longer than corresponding of Oudenodon to capture changes in tissue microstructure. tail neural spines, the cervical (neck) vertebrae are hetero- Then, we compared these thin-sections to similar regions of coelous (saddle-shaped articular surface), the cervical ribs the skull in Diictodon, which lacks cranial elaboration. In the are absent as distinct ossi???cations, and the chevrons are bone tissue of both Oudenodon and Diictodon, we observed fused to their respective centra. In recent years, both three- a cancellous, spongey interior sandwiched between two lay- dimensionally preserved partial skeletons and isolated ma- ers of compact cortical bone. This pattern of bone is typical terial of drepanosauromorphs have been found across both in many modern skulls but the thickness of the cancellous Europe and North America. These discoveries have helped region in Oudenodon is strikingly thicker, even in regions shape our understanding of the biology and diversity of away from the boss. We hypothesize that increased cranial drepanosauromorphs. However, comparing isolated, three di- thickness in Oudenodon is due to this middle expansion of mensionally preserved specimens to the more complete, yet spongey, cancellous tissue. As a result of the increased bone two dimensionally preserved articulated specimens is diffi- thickness, sutures in Oudenodon are deep, wide, and convo- cult due to differences in preservation. Here, we describe a luted when compared to the relatively simple interdigitated new drepanosauromorph species from the Chinle Formation sutures in Diictodon. These and other histologic comparisons in Petrified Forest National Park, Arizona based on the left with distantly related taxa allow us to interpret the growth second manual ungual (claw) . Some of the characteristics and construction of cranial elaboration in synapsids, adding that distinguish this claw from those of most drepanosauro- to our understanding of how these thickened skulls evolved. morphs is its size. It differs significantly from all known Future work can also explore the possible soft tissue covering Drepanosaurus specimens (like the Italian holotype and the of these bosses and domes, which may have been used for Hayden Quarry Drepanosaurus) because of the ventral place- intraspecific display or combat. ment of the cotyle (articulation surface), the height of the claw, the lack of compression along the pre-axial/post-axial plane, and a furrow along the midline. This new taxon not Undergraduate Research Program 1 www.uw.edu/undergradresearch only highlights unsuspected morphological variation within if un-iodized table salt may be an alternative to IMI, specifi- Drepanosauromorpha, but also helps sheds light on the evolu- cally targeting juvenile shrimp (recruits) inhabiting the upper tionary history of smaller-bodied reptiles within Late Triassic 10-15 cm of the sediment. Studies in 2018 indicated that a ecosystems. 2-3-fold increase in salinity resulted in 100% mortality when juveniles were exposed in artificial seawater. In 2019, we ex- posed juveniles (3 replicates, 5 shrimp each) within 10 cm POSTER SESSION 4 of native sediment to five different salt solutions to achieve Commons East, Easel 50 sediment pore water salinities of 25 (ambient, control), 35, 4:00 PM to 6:00 PM 50, 70, and 100 ppt. Salt solutions were prepared with na- tive seawater, added on top of the sediment (depth = 2 cm), Is Table Salt a Viable Alternative for the Control of and allowed to percolate through the sediment column for 6 Burrowing Shrimp on Shellfish Beds in Washington h (low tide). At 6 h, 2 cm of ambient seawater (25 ppt) were State? added to simulate tidal inundation and allowed to remain on Kylie Sahota, Junior, Aquatic & Fishery Sciences the surface for 12 h (low-high + high low tide) with two sub- NASA Space Grant Scholar, UW Honors Program sequent drawdowns and tidal inundations at 25 ppt (total test Eric R. Anderson, Junior, Environmental Science & duration = 48 h). The sediment was then sieved to remove the Resource Management shrimp and determine mortality. Average survival of controls William Gaege Baxter, Junior, Environmental Science & (25 ppt) was 73.3% whereas none of the shrimp exposed to Resource Management elevated salinities survived. Additional tests are underway to Rose Ann Denney, Senior, Environmental Science & examine different exposure scenarios. Results to date suggest Resource Management (Wildlife Conservation) table salt may be a viable and greener alternative to IMI. Victoria S (Victoria) Fleck, Junior, Environmental Science & Resource Management (Landscape Ecology & Conservation), History Isabela Sofia Garcia, Senior, Environmental Science & Resource Management (Wildlife Conservation) Raegan E. Jarvis, Junior, Aquatic & Fishery Sciences Claire Louise Johnston, Junior, Environmental Science & Resource Management Claudia R Penney, Sophomore, Aquatic & Fishery Sciences, Marine Biology Allison Phillips, Junior, Environmental Science & Resource Management Iona Mae Rohan, Senior, Environmental Science & Resource Management (Wildlife Conservation) Gushneet Singh Sarna, Senior, Environmental Science & Resource Management Jonathan L. (Jon) Schroeder, Junior, Aquatic & Fishery Sciences Zach Thomas, Junior, Aquatic & Fishery Sciences, Spanish Ariana Winkler, Senior, Environmental Studies, Environmental Science & Resource Management UW Honors Program Mentor: Christian Grue, Aquatic & Fishery Sciences Imidacloprid (IMI), a neonicotinoid insecticide, is being sought by shellfish growers to control burrowing shrimp (ghost shrimp, Neotropea californiensis) in Willapa Bay and Grays Harbor, Washington. The shrimp destabilize sediments resulting in poor survival and low yields of the commercially harvested Pacific oyster (Crassostrea gigas), threatening the local shellfish industry. A permit for the use of IMI has been denied by the State, Pacific County has declared an economic emergency, and the outcome of an appeal by the growers re- mains uncertain. We have undertaken studies to determine 2.
Load more

Recommended publications
  • An Evaluation of the Phylogenetic Relationships of the Pterosaurs Among Archosauromorph Reptiles
    Journal of Systematic Palaeontology 5 (4): 465–469 Issued 19 November 2007 doi:10.1017/S1477201907002064 Printed in the United Kingdom C The Natural History Museum An evaluation of the phylogenetic relationships of the pterosaurs among archosauromorph reptiles David W. E. Hone∗ Department of Earth Sciences, University of Bristol, Queens Road, Bristol, BS8 1RJ, UK Michael J. Benton Department of Earth Sciences, University of Bristol, Queens Road, Bristol, BS8 1RJ, UK SYNOPSIS The phylogenetic position of pterosaurs among the diapsids has long been a contentious issue. Some recent phylogenetic analyses have deepened the controversy by drawing the pterosaurs down the diapsid tree from their generally recognised position as the sister group of the dinosaur- omorphs, to lie close to the base of Archosauria or to be the sister group of the protorosaurs. Critical evaluation of the analyses that produced these results suggests that the orthodox position retains far greater support and no close link can be established between pterosaurs and protorosaurs. KEY WORDS Pterosauria, Prolacertiformes, Archosauria, Archosauromorpha, Ornithodira Contents Introduction 465 Methods and Results 466 Discussion 467 Re-analysis of Bennett (1996) 467 Re-analysis of Peters (2000) 467 Conclusions 469 Acknowledgements 469 References 469 Introduction tained). Muller¨ (2003, 2004) also suggested that the prolacer- tiforms were not a valid clade, with Trilophosaurus splitting The basal archosaurs and their phylogenetic positions relative his two prolacertiform taxa (Prolacerta and Tanystropheus). to one another within the larger clade Archosauromorpha The analysis performed by Senter (2004) also found the pro- have been a source of controversy among palaeontologists lacertiforms to be paraphyletic, although here he removed the for decades.
    [Show full text]
  • The Shoulder Girdle and Anterior Limb of Drepanosaurus Unguicaudatus
    <oological Journal of the Linnean Socieg (1994), Ill: 247-264. With 12 figures The shoulder girdle and anterior limb of Drepanosaurus unguicaudatus (Reptilia, Neodiapsida) from the upper Triassic (Norian) Downloaded from https://academic.oup.com/zoolinnean/article/111/3/247/2691415 by guest on 27 September 2021 of Northern Italy SILVIO RENESTO Dipartimento di Scienze della Terra, Universita degli Studi, Via Mangiagalli 34, I-20133 Milano, Italy Received January 1993, accepted for publication February 1994 A reinvestigation of the osteology of the holotype of Drepanosaurus unguicaudatus Pinna, 1980 suggests that in earlier descriptions some osteological features were misinterpreted, owing to the crushing of the bones and because taphonomic aspects were not considered. The pattern of the shoulder girdle and fore-limb was misunderstood: the supposed interclavicle is in fact the right scapula, and the bones previously identified as coracoid and scapula belong to the anterior limb. The new reconstruction of the shoulder girdle, along with the morphology of the phalanges and caudal vertebrae, leads to a new hypothesis about the mode oflife of this reptile. Drepanosaurus was probably an arboreal reptile which used its enormous claws to scrape the bark from trees, perhaps in search of insects, just as the modern pigmy anteater (Cyclopes) does. Available diagnostic characters place Drepanosaurus within the Neodiapsida Benton, but it is impossible to ascribe this genus to one or other of the two major neodiapsid lineages, the Archosauromorpha and the Lepidosauromorpha. ADDITIONAL KEY WORDS:-Functional morphology - taxonomy - taphonomy - palaeoecology . CONTENTS Introduction ................... 247 Taphonomy ..... .............. 249 Systematic palaeontology . .............. 251 Genus Drepanosaurus Pinna, 1980 .............. 252 Drepannsaurus unguicaudatus Pinna, 1980.
    [Show full text]
  • Tiago Rodrigues Simões
    Diapsid Phylogeny and the Origin and Early Evolution of Squamates by Tiago Rodrigues Simões A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in SYSTEMATICS AND EVOLUTION Department of Biological Sciences University of Alberta © Tiago Rodrigues Simões, 2018 ABSTRACT Squamate reptiles comprise over 10,000 living species and hundreds of fossil species of lizards, snakes and amphisbaenians, with their origins dating back at least as far back as the Middle Jurassic. Despite this enormous diversity and a long evolutionary history, numerous fundamental questions remain to be answered regarding the early evolution and origin of this major clade of tetrapods. Such long-standing issues include identifying the oldest fossil squamate, when exactly did squamates originate, and why morphological and molecular analyses of squamate evolution have strong disagreements on fundamental aspects of the squamate tree of life. Additionally, despite much debate, there is no existing consensus over the composition of the Lepidosauromorpha (the clade that includes squamates and their sister taxon, the Rhynchocephalia), making the squamate origin problem part of a broader and more complex reptile phylogeny issue. In this thesis, I provide a series of taxonomic, phylogenetic, biogeographic and morpho-functional contributions to shed light on these problems. I describe a new taxon that overwhelms previous hypothesis of iguanian biogeography and evolution in Gondwana (Gueragama sulamericana). I re-describe and assess the functional morphology of some of the oldest known articulated lizards in the world (Eichstaettisaurus schroederi and Ardeosaurus digitatellus), providing clues to the ancestry of geckoes, and the early evolution of their scansorial behaviour.
    [Show full text]
  • Zogno, Bergamo, Italy)
    Rivista Italiana di Paleontologia e Stratigrafia volume luz numero 1 pagrne 131 134 Aprile 1996 NOTE BREW AN EXCEPTIONAL REPTILE FIND IN THE NORIAN (LATE TRIASSIC) LAGERSTÀ.TTE OF ENDENNA (ZOGNO, BERGAMO, ITALY) ANDREA TINTORI, SILVIO RENESTO, CRISTINA LOMBARDO, GIANLUCA MANAROLLA. MATTEO MANENTI & MASSIMILIANO VENDiCO K^,-",,^.).. p--r;li. Norian (Late Triassic), Calcare di zorztno, Hundreds of fishes have been collected during six Lombardy Italy), new find. Q.tronhern years of digging (Beltan & Tintori, 1980; Tintori, 1980, Riassunta" Durante un sopralluogo nella località di Endenna 198t, 1983, !99Q, 199L, 1992, 1995; Tintori & Renesro, (Zogno, BG) il 5.10.95 è stato rinvenuto un frammento di un grande 1983; Tintori & Sassi, t992), together wirh some reptiles rettile parzialmente danneggiato da scavatori abusivi. Dopo il salva- (Padian, 1981; Pinna, 1,979,1,980, 1984;Pinna 6c Nosot- taggio del blocco già isolato, si è proweduto alla ricerca e al recupero ti, 1989; Renesto 1.984, 1992, 1,993,1994a,b, c, t995a,b; della rimanente pane dell'esemplare. Durante questi lavori sono an- che stati sorpresi alcuni scavatori abusivi che sono stati segnalati alla Renesto & Tintori, 1995) and several, mostly undescri- competente Soprintendenza. Il rettile si presenta completamente in- bed, invertebrates (Basso & Tintori, 1994). globato in matrice calcarea molto tenace e si prefigura parzialmente On the last 5th of October, the senior author was arrotolato e con il cranio disarticolato rispetto al resto del corpo. La accompanying Dr. W. Bausch (Erlangen, Germany) to a hnghezza totale supera i 4 m e 1o stato di conservazione è da ritener- si ottimo. Sulla base di osservazioni preliminari si può ipotizzare 1a survey for geochemical sampling in Endenna.
    [Show full text]
  • An Early Late Triassic Long-Necked Reptile with a Bony Pectoral Shield and Gracile Appendages
    An early Late Triassic long-necked reptile with a bony pectoral shield and gracile appendages JERZY DZIK and TOMASZ SULEJ Dzik, J. and Sulej, T. 2016. An early Late Triassic long-necked reptile with a bony pectoral shield and gracile appendages. Acta Palaeontologica Polonica 61 (4): 805–823. Several partially articulated specimens and numerous isolated bones of Ozimek volans gen. et sp. nov., from the late Carnian lacustrine deposits exposed at Krasiejów in southern Poland, enable a reconstruction of most of the skeleton. The unique character of the animal is its enlarged plate-like coracoids presumably fused with sterna. Other aspects of the skeleton seem to be comparable to those of the only known specimen of Sharovipteryx mirabilis from the latest Middle Triassic of Kyrgyzstan, which supports interpretation of both forms as protorosaurians. One may expect that the pectoral girdle of S. mirabilis, probably covered by the rock matrix in its only specimen, was similar to that of O. volans gen. et sp. nov. The Krasiejów material shows sharp teeth, low crescent scapula, three sacrals in a generalized pelvis (two of the sacrals being in contact with the ilium) and curved robust metatarsal of the fifth digit in the pes, which are unknown in Sharovipteryx. Other traits are plesiomorphic and, except for the pelvic girdle and extreme elongation of appendages, do not allow to identify any close connection of the sharovipterygids within the Triassic protorosaurians. Key words: Archosauromorpha, Sharovipteryx, protorosaurs, gliding, evolution, Carnian, Poland. Jerzy Dzik [[email protected]], Instytut Paleobiologii PAN, ul. Twarda 51/55, 00-818 Warszawa, Poland and Wydział Biologii Uniwersytetu Warszawskiego, Centrum Nauk Biologiczno-Chemicznych, ul.
    [Show full text]
  • Ancient Reptile Fossils Claw for More Attention 29 September 2016, by Jim Shelton
    Ancient reptile fossils claw for more attention 29 September 2016, by Jim Shelton can evolve in the limbs of four-footed animals," said Adam Pritchard, a postdoctoral researcher at Yale and first author of the study. "Ecologically, Drepanosaurus seems to be a sort of chameleon- anteater hybrid, which is really bizarre for the time. It possesses a totally unique forelimb." Four-limbed animals with a backbone are called tetrapods. In nearly all tetrapods, the forearm is made up of two, elongate and parallel bones—the radius and the ulna. These bones connect to a series of much shorter, wrist bones at the base of the hand. Drepanosaurus, however, has radius and ulna In this illustration set 212 million years ago in what is bones that are not parallel. Instead, the ulna is a today New Mexico, a Drepanosaurus rips away tree bark flat, crescent-shaped bone. Also, the two wrist with its massive claw and powerful arm. Credit: Painting bones that meet the end of the ulna are long rather by Victor Leshyk than short. They are longer than the radius, in fact. "The bone contacts suggest that the enlarged claw of Drepanosaurus could have been hooked into Newly recovered fossils confirm that insect nests," Pritchard said. "The entire arm could Drepanosaurus, a prehistoric cross between a then have been powerfully retracted to tear open chameleon and an anteater, was a small reptile the nest. This motion is very similar to the hook-and- with a fearsome finger. The second digit of its pull digging of living anteaters, which also eat forelimb sported a massive claw.
    [Show full text]
  • Structure of the Tail of a Phytosaur (Reptilia, Archosauria) from the Norian (Late Triassic) of Lombardy (Northern Italy)
    Rivista Italiana di Paleontologia e Stratigrafia volume I u) numero 1 tavole 1 naoinc I ì5-1 4a Aprile 1999 NOTA BREVE . SHORT NOTE STRUCTURE OF THE TAIL OF A PHYTOSAUR (REPTILIA, ARCHOSAURIA) FROM THE NORIAN (LATE TRIASSIC) OF LOMBARDY (NORTHERN ITALY) SIVIO RENESTOX & CRISTINA LOMBARDO* Receiped Ntnentber 2, 1998; accepted December 3, 1998 Key"uords: Reptilia, Archosauria, Phytosauridae, Norian (Late sent endemic or poorly known taxa. Despite the deposi- Triassic), Lombardy (Nonhern Italy), new specimen, caudal verre- tional environment (marine basins amid carbonate brae, functional morphology. a platform; Jadoul, 1986; Jadoul et aI., 1992), rerresrrial Riassunto. In questa nota viene descritta la morfologia della reptiles are more common than aquatic ones, suggesting porzione caudale della colonna venebrale di uno scheletro completo the presence of land nearby, possibly ephemeral islands di Fitosauro (Reptilia, Diapsida, Phytosauria) rinvenuto nel Calcare di with freshwater reservoirs in which insecrs (Vhaiiey, Zorzino, di età Norica (Triassico Superiore), nella località fossilifera di Endenna (Zogno, Bergamo). Lo stato di avanzamento del lavoro di 1986) and endemic reptiles lived. Marine repriles are rep- preparazione consente una descrizione precisa della morfologia delle resented by the placodont Psephoderma (Pinna & Nosot- vertebre caudali, e del loro numero complessivo. La struttura del cra- ti, 1989; Renesto & Tintori, 1995) and the thalattosaur nio, non ancora completamente preparato, fa supporre affinità con il Endennasaurars (Renesto, 1984, 1992). Among non-mari- genere Mystriosuchus, m l'attribuzione è per ora ipotetica. La presen- za di un' adattamento alla locomozione in acqua più spinto che in ne reptiles, the oldest pterosaurs so far known have altri Fitosauri è testimonìato dalla morfologia delle emapofisi e delle been collected $fild, 1978, 1984; Renesto, 1993), along spine neurali, finora non figurata in letteratura per i fitosauri.
    [Show full text]
  • 1 a New Lepidosaur Clade
    A new lepidosaur clade: the Tritosauria DAVID PETERS Independent researcher, 311 Collinsville Avenue, Collinsville, Illinois 62234 U.S.A. [email protected] RH: PETERS—TRITOSAURIA 1 ABSTRACT—Several lizard-like taxa do not nest well within the Squamata or the Rhynchocephalia. Their anatomical differences separate them from established clades. In similar fashion, macrocnemids and cosesaurids share few traits with putative sisters among the prolacertiformes. Pterosaurs are not at all like traditional archosauriforms. Frustrated with this situation, workers have claimed that pterosaurs appeared without obvious antecedent in the fossil record. All these morphological ‘misfits’ have befuddled researchers seeking to shoehorn them into established clades using traditional restricted datasets. Here a large phylogenetic analysis of 413 taxa and 228 characters resolves these issues by opening up the possibilities, providing more opportunities for enigma taxa to nest more parsimoniously with similar sisters. Remarkably, all these ‘misfits’ nest together in a newly recovered and previously unrecognized clade of lepidosaurs, the Tritosauria or ‘third lizards,’ between the Rhynchocephalia and the Squamata. Tritosaurs range from small lizard-like forms to giant marine predators and volant monsters. Some tritosaurs were bipeds. Others had chameleon-like appendages. With origins in the Late Permian, the Tritosauria became extinct at the K–T boundary. Overall, the new tree topology sheds light on this clade and several other ‘dark corners’ in the family tree of the Amniota. Now pterosaurs have more than a dozen antecedents in the fossil record documenting a gradual accumulation of pterosaurian traits. INTRODUCTION The Lepidosauria was erected by Romer (1956) to include diapsids lacking archosaur characters. Later, with the advent of computer-assisted phylogenetic analyses, 2 many of Romer’s ‘lepidosaurs’ (Protorosauria/Prolacertiformes, Trilophosauria, and Rhynchosauria) were transferred to the Archosauromorpha (Benton, 1985; Gauthier, 1986).
    [Show full text]
  • Kyrgyzsaurus Bukhanchenkoi Gen. Et Sp. Nov. – Новое Пресмыкающееся Из Триаса ЮгоЗападного Кыргызстана © 2011 Г
    ПАЛЕОНТОЛОГИЧЕСКИЙ ЖУРНАЛ, 2011, № 6, с. 42–50 УДК 568.1:551.761 KYRGYZSAURUS BUKHANCHENKOI GEN. ET SP. NOV. – НОВОЕ ПРЕСМЫКАЮЩЕЕСЯ ИЗ ТРИАСА ЮГОЗАПАДНОГО КЫРГЫЗСТАНА © 2011 г. В. Р. Алифанов, Е. Н. Курочкин Палеонтологический институт им. А.А. Борисяка РАН e%mail: [email protected]; e%mail: [email protected] Поступила в редакцию 22.12.2010 г. Принята к печати 16.03.2010 г. Из триасовых отложений (мадыгенская свита) ЮгоЗападного Кыргызстана описан архаичный представитель семейства Drepanosauridae (Archosauromorpha, Reptilia) – Kyrgyzsaurus bukhanchenkoi gen. et sp. nov. Материал представлен передней частью скелета (череп, шейные и передние грудные позвонки, ребра, элементы плечевого пояса) с отпечатками кожного покрова. Укороченные ветви нижней челюсти, многочисленные зубы, мелкие остеодермы, широкие кожные надглазничные ко зырьки и массивный горловой мешок – наиболее яркие особенности новой формы. Мадыгенская свита, имеющая озерноречной ДжайляуЧо. Более детальные обзоры палеонтоло генезис, выходит на поверхность в югозападной гических находок из отложений мадыгенской сви части Кыргызстана восточнее кишлака Мадыген ты представлены в недавних работах С. Фогта с со двумя обнажениями (местонахождениями): север авторами (Voigt et al., 2006) и Д.Е. Щербакова ным (ДжайляуЧо) и южным (Мадыген; иногда это (Shcherbakov, 2008). название так же применяется и для северного ме Ниже охарактеризовано новое триасовое пре стонахождения). Максимальная мощность ее выхо смыкающееся – Kyrgyzsaurus bukhanchenkoi gen. дов составляет более 500 м. Обильные палеофлори et sp. nov. Единственный образец этой формы был стические сборы позволяют датировать отложения обнаружен в 2006 г. во время работ Совместной Рос свиты концом среднего или началом позднего три сийскоГерманской экспедиции по исследованию аса (Добрускина, 1980; Dobruskina, 1995). В ком триасовых отложений ЮгоЗападного Кыргызста плексе мадыгенских животных преобладают насе на (2005 и 2006 гг.).
    [Show full text]
  • Micro- and Small Vertebrate Biostratigraphy and Biochronology of the Upper Triassic Chinle Group, Southwestern Usa
    Harris et al., eds., 2006, The Triassic-Jurassic Terrestrial Transition. New Mexico Museum of Natural History and Science Bulletin 37. 94 MICRO- AND SMALL VERTEBRATE BIOSTRATIGRAPHY AND BIOCHRONOLOGY OF THE UPPER TRIASSIC CHINLE GROUP, SOUTHWESTERN USA ANDREW B. HECKERT1 AND SPENCER G. LUCAS2 1Department of Geology, Appalachian State University, ASU Box 32067, Boone, NC 28608-2067; 2New Mexico Museum of Natural History and Science, 1801 Mountain Road NW, Albuquerque, NM 87104-1375 Abstract—A long-term goal of vertebrate biostratigraphers is to construct a microvertebrate biostratigraphy for lower Mesozoic rocks that complements and extends the mammal-based biostratigraphy in place for Upper Cretaceous-Recent deposits. Here we report substantial progress toward achieving this goal based on the distribu- tion of microvertebrate fossils in the Upper Triassic Chinle Group of the western USA. This biostratigraphic hypothesis independently corroborates the existing macrovertebrate biostratigraphy, recognizing four temporally successive assemblages—the Otischalkian, Adamanian, Revueltian, and Apachean, with subdivisions of the Adamanian (St. Johnsian and Lamyan) and Revueltian (Barrancan and Lucianoan). Many microvertebrate taxa, unfortunately, have long stratigraphic ranges and thus, while widespread and easily recognized, are not reliable index fossils. These taxa include the chondrichthyans Lissodus and Reticulodus synergus, most lepidosauromorphs (including sphenodontians), and various microvertebrate archosauromorphs. However, other taxa have relatively short stratigraphic ranges and occur in multiple localities and thus have some utility as index taxa. Adamanian index taxa include the procolophonid(?) Colognathus obscurus and the putative ornithischians Tecovasaurus murryi, Crosbysaurus harrisae and Krzyzanowskisaurus hunti. Revueltian index taxa include the chondrichthyan Reticulodus synergus, the crurotarsan Revueltosaurus callenderi and the cynodont Pseudotriconodon chatterjeei.
    [Show full text]
  • A Long−Necked Archosauromorph from the Early Triassic of Poland
    A LONG−NECKED ARCHOSAUROMORPH FROM THE EARLY TRIASSIC OF POLAND MAGDALENA BORSUK−BIAŁYNICKA and SUSAN E. EVANS Borsuk−Białynicka, M. and Evans, S.E. 2009. A long−necked archosauromorph from the Early Triassic of Poland. Palaeontologia Polonica 65, 203–234. Czatkowiella harae gen. et sp. n. from the Early Triassic (earliest Late Olenekian) locality of Czatkowice 1, near Kraków, Poland, is characterised by a long slender neck, three headed ribs on some anterior dorsal vertebrae, and short broad neural spine tips in the dorsal verte− bral series. Cladistic analysis suggests a relationship between Czatkowiella and the Late Permian long−necked reptile Protorosaurus, but fails to support a monophyletic Prolacerti− formes. Czatkowiella and Protorosaurus do not group with either Prolacerta or the Tany− stropheus/ Macrocnemus clade of other workers, and fall at the very base of Archosauro− morpha. Thus the long−necked morphology of many archosauromorph taxa should be re− garded as a primitive state within this group, reversed in some daughter lineages such as rhynchosaurs and trilophosaurs. Key words: Archosauromorpha, Reptile, Protorosaurus, Early Triassic, Poland, micro− vertebrates. Magdalena Borsuk−Białynicka[[email protected]], Institut Paleobiologii PAN, Twarda 51/55, PL−00−818 Warszawa, Poland. Susan E. Evans [[email protected]], Research Department of Cell and Developmental Biol− ogy, UCL, University College London, Gower Street, London, WC1E 6BT, UK. Received 4 April 2006, accepted 15 September 2008 204 MAGDALENA BORSUK−BIAŁYNICKA and SUSAN E. EVANS INTRODUCTION A small diapsid reptile Czatkowiella harae gen. et sp. n. is here described from the Early Triassic fissure deposits of southern Poland (Czatkowice 1 near Kraków; Paszkowski and Wieczorek 1982).
    [Show full text]
  • 1 Youngoides Romeri and the Origin of the Archosauriformes DAVID
    Youngoides romeri and the origin of the Archosauriformes DAVID PETERS Independent researcher 311 Collinsville Avenue, Collinsville, IL U.S.A. [email protected] 1 ABSTRACT—Prior workers reported that all specimens attributed to Youngopsis and Youngoides could not be distinguished from the holotype of Youngina capensis. Others considered all specimens attributed to Proterosuchus, Chasmatosaurus, and Elaphrosuchus conspecific. In both cases distinct skull shapes were attributed to taphonomic variations due to distortion pressure or allometric growth. Here a large phylogenetic analysis of the Amniota (401 taxa) tests those hypotheses. The resulting tree recovers a den of small Youngina specimens preceding the Protorosauria. Another specimen nests at the base of the Protorosauria. Six others nest between the Protorosauria and the Archosauriformes. The most derived of these bears a nascent antorbital fenestra. Two other putative Youngina specimens nest at unrelated nodes. In like fashion, the various specimens assigned to Proterosuchus are recovered in distinct clades. One leads to the Proterochampsidae, Parasuchia and Choristodera. The latter lost the antorbital fenestra. Another clade leads to all higher archosauriforms. The present analysis reveals an evolutionary sequence shedding new light on the origin and radiation of early archosauriforms. Taphonomic distortion pressure and allometry during ontogeny were less of a factor than previously assumed. The splitting of several specimens currently considered Youngina and Proterosuchus into distinct genera and species is supported here. INTRODUCTION The Archosauriformes is a widely recognized monophyletic clade that includes, by definition, the most recent common ancestor of Proterosuchidae, Erythrosuchidae, 2 Proterochampsidae, and Archosauria (Gauthier, 1986). Later studies (e.g., Sereno, 1991; Parrish, 1993; Juul, 1994; Ezcurra, 2010; Nesbitt, 2011) have universally rooted their archosauriform clades on Proterosuchidae or Proterosuchus.
    [Show full text]