DOCSLIB.ORG

Late Triassic) Adrian P

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Late Triassic) Adrian P New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/56 Definition and correlation of the Lamyan: A new biochronological unit for the nonmarine Late Carnian (Late Triassic) Adrian P. Hunt, Spencer G. Lucas, and Andrew B. Heckert, 2005, pp. 357-366 in: Geology of the Chama Basin, Lucas, Spencer G.; Zeigler, Kate E.; Lueth, Virgil W.; Owen, Donald E.; [eds.], New Mexico Geological Society 56th Annual Fall Field Conference Guidebook, 456 p. This is one of many related papers that were included in the 2005 NMGS Fall Field Conference Guidebook. Annual NMGS Fall Field Conference Guidebooks Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. These books have set the national standard for geologic guidebooks and are an essential geologic reference for anyone working in or around New Mexico. Free Downloads NMGS has decided to make peer-reviewed papers from our Fall Field Conference guidebooks available for free download. Non-members will have access to guidebook papers two years after publication. Members have access to all papers. This is in keeping with our mission of promoting interest, research, and cooperation regarding geology in New Mexico. However, guidebook sales represent a significant proportion of our operating budget. Therefore, only research papers are available for download. Road logs, mini-papers, maps, stratigraphic charts, and other selected content are available only in the printed guidebooks. Copyright Information Publications of the New Mexico Geological Society, printed and electronic, are protected by the copyright laws of the United States. No material from the NMGS website, or printed and electronic publications, may be reprinted or redistributed without NMGS permission. Contact us for permission to reprint portions of any of our publications. One printed copy of any materials from the NMGS website or our print and electronic publications may be made for individual use without our permission. Teachers and students may make unlimited copies for educational use. Any other use of these materials requires explicit permission. This page is intentionally left blank to maintain order of facing pages. NewDEFINITION Mexico Geological AND Society CORRELATION Guidebook, 56th Field Conference, OF THE Geology LAMYAN of the Chama Basin, 2005, p. 357-366. 357 DEFINITION AND CORRELATION OF THE LAMYAN: A NEW BIOCHRONOLOGICAL UNIT FOR THE NONMARINE LATE CARNIAN (LATE TRIASSIC) ADRIAN P. HUNT, SPENCER G. LUCAS, AND ANDREW B. HECKERT New Mexico Museum of Natural History and Science, 1801 Mountain Road NW, Albuquerque, NM 87104-1375 ABSTRACT.—The Sonsela Member of the Petrified Forest Formation at Petrified Forest, Arizona and the Tres Lagunas Member of the Santa Rosa Formation in east-central New Mexico yield vertebrate fossil assemblages (faunas) that are intermediate in composition between the Adamanian and Revueltian lvfs in that they include co-occurrences of the phytosaurs Rutiodon and Pseudopalatus and the unique taxon Typothorax antiquum. These faunas define an upper subdivision of Adamanian time that we refer to as the Lamyan sub-faunachron. The earlier Adamanian is distinguished as the St. Johnsian sub-faunachron. This refinement demonstrates the utility of defining biochronologic units in that it spurs detailed examination of biostratigraphy and lithostratigraphy. The Lamyan provides evidence that there is no major tetrapod extinction within the Late Triassic, specifically at the end of the Carnian. INTRODUCTION Long and Murry, 1995; Lucas, 1998) recognized this fundamen- tal division, together with other tetrapod taxa (including phyto- The most complete sequence of Late Triassic nonmarine tetra- saurs) defining older and younger portions of the Chinle. pod fossil assemblages (faunas) is in the Chinle Group of west- Aetosaurs, which were originally considered to be a subset of ern North America (Lucas, 1997). These faunas have formed the phytosaurs, began to have biochronological utility with the work basis of a biochronological scheme that has global utility (Lucas of Gregory (e. g., 1953) and later Long and Ballew (1985), who and Hunt, 1993; Lucas, 1997, 1998, 1999). Thus, Lucas and Hunt clarified issues of alpha taxonomy. Thus, Lucas and Hunt (1993) (1993) defined four land-vertebrate faunachrons (lvfs) to encom- recognized four land-vertebrate faunachrons (LVFs) based pri- pass Late Triassic time based on the faunas of the Chinle Group. marily on the temporal distribution of the genera of phytosaurs Subsequently, Lucas and others (Lucas et al., 1997; Lucas, 1998; and aetosaurs, which are in ascending order of age: Otischalkian, Hunt, 2001) further refined this biochronology, which was prin- Adamanian, Revueltian and Apachean. The Adamanian (late Car- cipally based on the stratigraphic ranges of genera of phytosaurs nian) and Revueltian (Norian) are of concern here. The Adama- and aetosaurs. nian is based on index taxa that include the phytosaur Rutiodon Recent work has refined the stratigraphic ranges of known tet- and the aetosaurs Desmatosuchus haplocerus and Stagonolepis, rapod taxa and has recognized new records of taxa in strata of and the Revueltian includes the phytosaur Pseudopalatus and the Adamanian age. These new data are principally from the Petrified aetosaur Typothorax. Forest National Park (Heckert and Lucas, 2002; Hunt et al., 2002; It is important to note that this biochronology has held up Woody, 2003; Woody and Parker, 2004) in Arizona and the exten- remarkably well, and in some cases has been improved, in spite sive exposures of the Chinle Group in east-central New Mexico of extensive work on the systematics and stratigraphic distribu- (Hunt and Lucas, 1995b, 2005; Lucas et al., 2002). The purpose tion of the key index taxa, especially the aetosaurs (e.g., Lucas of this paper is to review some of these data as they relate to the and Heckert, 1996; Heckert and Lucas, 1998b, 2000). Lucas et late Carnian-Norian succession of tetrapod fossil assemblages in al. (2002a) distinguished a new species of Typothorax, T. anti- New Mexico and Arizona and to distinguish and define new bio- quum, and demonstrated that this taxon is restricted to the later chronological intervals that further refine the existing biochrono- Adamanian, whereas the type species, T. coccinarum, is an index logical scheme. taxon of the Revueltian. Similarly, Zeigler et al. (2002a) identi- fied a new species of Desmatosuchus, D. chamaensis, which is LATE TRIASSIC BIOCHRONOLOGY BASED ON restricted to strata of Revueltian age. PHYTOSAURS AND AETOSAURS EAST-CENTRAL NEW MEXICO All vertebrate biochronologies of the Late Triassic have been primarily based on phytosaurs. Camp (1930), in his classic mono- Lithostratigraphy of the Chinle Group graph on phytosaurs, recognized a lower interval of the Chinle Group characterized by various species of Machaeroprosopus (e. Rich (1921) first published the name Santa Rosa Sandstone g. M., adamanensis, M. lithodendorum, M. zunii), which are now in reference to a sandstone-dominated package at the base of referred to Rutiodon (Leptosuchus of some authors e.g., Long and the Triassic sequence in east-central New Mexico, and Darton Murry, 1995), and an upper Chinle Group interval characterized (1922, p. 183) formally named it (Fig. 1). Following Gorman by the species M. tenuis, M. andersoni and M. validus, which are and Robeck (1946), several workers subdivided the Santa Rosa now referred to Pseudopalatus (e.g., Ballew, 1989; Hunt, 1994; Formation. Lucas and Hunt (1987) removed the basal unit as the Long and Murry, 1995). These and subsequent authors (e. g., Anton Chico Member of the Moenkopi Formation and formal- Long and Ballew, 1985; Ballew, 1989; Lucas and Hunt, 1993; ized a subdivision of the remaining portion of the Santa Rosa 358 HUNT, LUCAS, AND HECKERT Formation into members, in ascending order: Tecolitito (up to 34 m of sandstone and conglomerate), Los Esteros (up to 44 m of dominantly mudstone and subordinate sandstone and conglom- erate), and Tres Lagunas (up to 46 m of dominantly sandstone with subsidiary conglomerate and mudstone) (Fig. 1). The Tres Lagunas Member of the Santa Rosa Formation is usually a cliff- forming sandstone unit throughout most of its outcrop belt, but in Santa Fe County it consists of two sandstones with a medial mudstone interval (Fig. 1). Overlying the Santa Rosa Formation in east-central New Mexico is a sequence of stratigraphic units with a complex his- tory of nomenclature (Lucas et al., 1985; Lucas and Hunt, 1989) that are now assigned to the Chinle Group of Lucas (1993). These units are (in ascending order) the Garita Creek, Trujillo, Bull Canyon and Redonda formations (Lucas and Hunt, 1989; Lucas et al., 2001). The Garita Creek Formation was first distinguished as the “lower shale member” of the Chinle Formation by Kelley (1972), and it was subsequently formalized by Lucas and Hunt (1989). The Garita Creek is up to 76 m of mudstone with lesser amounts of sandstone and conglomerate. The Trujillo Formation is as much as 68 m-thick and is a domi- nantly sandstone unit that represents a medial, ledge-forming unit of the Chinle Group in east-central New Mexico. It was first rec- ognized in New Mexico by Darton (1928) and was named the Cuervo Member of the Chinle Formation (Kelley, 1972). Sub- sequently, Lucas and Hunt (1989) assigned these strata to the Trujillo Formation of Gould (1907). The Trujillo in eastern New Mexico is up to 68 m of mainly micaeous sandstone with minor beds of conglomerate and mudstone. Lucas and Hunt (1989) named the Bull Canyon Formation for strata previously referred to the “upper shale member of the Chinle Formation” by Kelley (1972). The Bull Canyon Forma- tion is up to 110 m of mostly mudstone, with lesser amounts of sandstone and minor beds of siltstone and conglomerate (Lucas et al., 2001).
Load more

Recommended publications
  • Ischigualasto Formation. the Second Is a Sile- Diversity Or Abundance, but This Result Was Based on Only 19 of Saurid, Ignotosaurus Fragilis (Fig
    This article was downloaded by: [University of Chicago Library] On: 10 October 2013, At: 10:52 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Journal of Vertebrate Paleontology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ujvp20 Vertebrate succession in the Ischigualasto Formation Ricardo N. Martínez a , Cecilia Apaldetti a b , Oscar A. Alcober a , Carina E. Colombi a b , Paul C. Sereno c , Eliana Fernandez a b , Paula Santi Malnis a b , Gustavo A. Correa a b & Diego Abelin a a Instituto y Museo de Ciencias Naturales, Universidad Nacional de San Juan , España 400 (norte), San Juan , Argentina , CP5400 b Consejo Nacional de Investigaciones Científicas y Técnicas , Buenos Aires , Argentina c Department of Organismal Biology and Anatomy, and Committee on Evolutionary Biology , University of Chicago , 1027 East 57th Street, Chicago , Illinois , 60637 , U.S.A. Published online: 08 Oct 2013. To cite this article: Ricardo N. Martínez , Cecilia Apaldetti , Oscar A. Alcober , Carina E. Colombi , Paul C. Sereno , Eliana Fernandez , Paula Santi Malnis , Gustavo A. Correa & Diego Abelin (2012) Vertebrate succession in the Ischigualasto Formation, Journal of Vertebrate Paleontology, 32:sup1, 10-30, DOI: 10.1080/02724634.2013.818546 To link to this article: http://dx.doi.org/10.1080/02724634.2013.818546 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content.
    [Show full text]
  • 8. Archosaur Phylogeny and the Relationships of the Crocodylia
    8. Archosaur phylogeny and the relationships of the Crocodylia MICHAEL J. BENTON Department of Geology, The Queen's University of Belfast, Belfast, UK JAMES M. CLARK* Department of Anatomy, University of Chicago, Chicago, Illinois, USA Abstract The Archosauria include the living crocodilians and birds, as well as the fossil dinosaurs, pterosaurs, and basal 'thecodontians'. Cladograms of the basal archosaurs and of the crocodylomorphs are given in this paper. There are three primitive archosaur groups, the Proterosuchidae, the Erythrosuchidae, and the Proterochampsidae, which fall outside the crown-group (crocodilian line plus bird line), and these have been defined as plesions to a restricted Archosauria by Gauthier. The Early Triassic Euparkeria may also fall outside this crown-group, or it may lie on the bird line. The crown-group of archosaurs divides into the Ornithosuchia (the 'bird line': Orn- ithosuchidae, Lagosuchidae, Pterosauria, Dinosauria) and the Croco- dylotarsi nov. (the 'crocodilian line': Phytosauridae, Crocodylo- morpha, Stagonolepididae, Rauisuchidae, and Poposauridae). The latter three families may form a clade (Pseudosuchia s.str.), or the Poposauridae may pair off with Crocodylomorpha. The Crocodylomorpha includes all crocodilians, as well as crocodi- lian-like Triassic and Jurassic terrestrial forms. The Crocodyliformes include the traditional 'Protosuchia', 'Mesosuchia', and Eusuchia, and they are defined by a large number of synapomorphies, particularly of the braincase and occipital regions. The 'protosuchians' (mainly Early *Present address: Department of Zoology, Storer Hall, University of California, Davis, Cali- fornia, USA. The Phylogeny and Classification of the Tetrapods, Volume 1: Amphibians, Reptiles, Birds (ed. M.J. Benton), Systematics Association Special Volume 35A . pp. 295-338. Clarendon Press, Oxford, 1988.
    [Show full text]
  • Tetrapod Biostratigraphy and Biochronology of the Triassic–Jurassic Transition on the Southern Colorado Plateau, USA
    Palaeogeography, Palaeoclimatology, Palaeoecology 244 (2007) 242–256 www.elsevier.com/locate/palaeo Tetrapod biostratigraphy and biochronology of the Triassic–Jurassic transition on the southern Colorado Plateau, USA Spencer G. Lucas a,⁎, Lawrence H. Tanner b a New Mexico Museum of Natural History, 1801 Mountain Rd. N.W., Albuquerque, NM 87104-1375, USA b Department of Biology, Le Moyne College, 1419 Salt Springs Road, Syracuse, NY 13214, USA Received 15 March 2006; accepted 20 June 2006 Abstract Nonmarine fluvial, eolian and lacustrine strata of the Chinle and Glen Canyon groups on the southern Colorado Plateau preserve tetrapod body fossils and footprints that are one of the world's most extensive tetrapod fossil records across the Triassic– Jurassic boundary. We organize these tetrapod fossils into five, time-successive biostratigraphic assemblages (in ascending order, Owl Rock, Rock Point, Dinosaur Canyon, Whitmore Point and Kayenta) that we assign to the (ascending order) Revueltian, Apachean, Wassonian and Dawan land-vertebrate faunachrons (LVF). In doing so, we redefine the Wassonian and the Dawan LVFs. The Apachean–Wassonian boundary approximates the Triassic–Jurassic boundary. This tetrapod biostratigraphy and biochronology of the Triassic–Jurassic transition on the southern Colorado Plateau confirms that crurotarsan extinction closely corresponds to the end of the Triassic, and that a dramatic increase in dinosaur diversity, abundance and body size preceded the end of the Triassic. © 2006 Elsevier B.V. All rights reserved. Keywords: Triassic–Jurassic boundary; Colorado Plateau; Chinle Group; Glen Canyon Group; Tetrapod 1. Introduction 190 Ma. On the southern Colorado Plateau, the Triassic– Jurassic transition was a time of significant changes in the The Four Corners (common boundary of Utah, composition of the terrestrial vertebrate (tetrapod) fauna.
    [Show full text]
  • The Triassic Period - 251 to 205 MY - Tectonics and Climate Life in the Oceans Jarðsaga 1 - Saga Lífs Og Lands – -Ólafur Ingólfsson the Triassic Period
    The Triassic Period - 251 to 205 MY - Tectonics and climate Life in the Oceans Jarðsaga 1 - Saga Lífs og Lands – -Ólafur Ingólfsson The Triassic Period The first period of the Mesozoic Era is the Triassic Period, which lasted from 251 to 205 million years ago. The name Triassic comes from Germany where it was originally named the Trias in 1834 by Friedrich August Von Alberti (1795- 1878) because it is represented by a three-part division of rock types in Germany. Triassic tectonic development In many ways, the Triassic was a time of transition. Pangea was fully assembled and remained so through the Triassic, affecting global climate and ocean circulation... Early Triassic climate The Triassic was a greenhouse world, with no evidence of ice at the poles. The interior of Pangea was hot and dry, and warm, temperate climates extended to the Poles. Pangea starts breaking up towards the end of the Triassic Towards the end of the Triassic, a rift develops between Gondwana and Laurasia The first chapter in the formation of the Atlantic Ocean... Late Triassic climate Global climate was warm during the Late Triassic. There was no ice at either North or South Poles. More pronounced climate zonation than during the Early Triassic, less extension of arid areas. Warm temperate conditions extended towards the poles. Space for new life forms to develop The Triassic followed the largest extinction event in the history of life, when 75-90% of all marine species vanished at the end of the Permian. This provided an opportunity for new lifeforms... Triassic marine deposits rather rare Sea level was fairly constant through the Triassic; lack of transgressions makes marine deposits rather rare in the geological record.
    [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]
  • Parker's (2003) Thesis
    CHAPTER 8 TAXONOMY OF THE STAGONOLEPIDIDAE SYSTEMATIC PALEONTOLOGY ARCHOSAURIA Cope, 1869 PSEUDOSUCHIA Zittel 1887-1890 sensu Gauthier, 1986 SUCHIA Krebs, 1974 STAGONOLEPIDIDAE Lydekker, 1887 Revised diagnosis -- Pseudosuchians that possess the following synapomorphies: premaxilla that is edentulous anteriorly and upturned into a mediolaterally expanded “shovel” at its terminus; external nares much longer than antorbital fenestra; supratemporal fenestra laterally exposed; small peg-like teeth possessing bulbous crowns that are waisted; posterior ramus of jugal downturned; mandible is “slipper-shaped” with an acute anterior terminus; dentary is edentulous anteriorly; posterior margin of parietal modified to receive paramedian scutes; proximal humerus greatly expanded with hypertrophied deltopectoral crest; femur, straight, not twisted, with a hypertrophied, knob-like fourth trochanter; laterally expanded transverse processes in the dorsal series that contain both rib facets; well-developed accessory (hyposphene-hypantrum) articulations on the dorsal vertebrae; iliac blade high, thickened dorsally; anterior iliac blade, short, robust, and slightly recurved ventrally; an extensive carapace of rectangular (wider than long) osteoderms occurring in four distinct rows; and extensive ventral and appendicular armor (Parrish, 1994; Long and Murry, 1995; Heckert and Lucas, 2000; Small, 2002). The synonymy lists in this chapter are modified from Heckert and Lucas (2000). STAGONOLEPININAE Heckert and Lucas, 2000 Huene (1942) originally used the name “Stagonolepinae” as a subfamily for Stagonolepis. Heckert and Lucas (2000) modified this to Stagonolepininae and defined it cladistically. Stagonolepininae is defined as a stem-based taxon by Heckert and Lucas (2000:1551) consisting of all stagonolepididids “more closely related to Stagonolepis than the last common ancestor of Stagonolepis and Desmatosuchus.” Stagonolepininae consists of Coahomasuchus + Aetosaurus + Stagonolepis + Typothoraxinae.
    [Show full text]
  • A Revision of the Upper Triassic Ornithischian Dinosaur Revueltosaurus, with a Description of a New Species
    Heckert, A.B" and Lucas, S.O., eds., 2002, Upper Triassic Stratigraphy and Paleontology. New Mexico Museum of Natural History & Science Bulletin No.2 J. 253 A REVISION OF THE UPPER TRIASSIC ORNITHISCHIAN DINOSAUR REVUELTOSAURUS, WITH A DESCRIPTION OF A NEW SPECIES ANDREW B. HECKERT New Mexico Museum of Natural History, 1801 Mountain Road NW, Albuquerque, NM 87104-1375 Abstract-Ornithischian dinosaur body fossils are extremely rare in Triassic rocks worldwide, and to date the majority of such fossils consist of isolated teeth. Revueltosaurus is the most common Upper Triassic ornithischian dinosaur and is known from Chinle Group strata in New Mexico and Arizona. Historically, all large (>1 cm tall) and many small ornithischian dinosaur teeth from the Chinle have been referred to the type species, Revueltosaurus callenderi Hunt. A careful re-examination of the type and referred material of Revueltosaurus callenderi reveals that: (1) R. callenderi is a valid taxon, in spite of cladistic arguments to the contrary; (2) many teeth previously referred to R. callenderi, particularly from the Placerias quarry, instead represent other, more basal, ornithischians; and (3) teeth from the vicinity of St. Johns, Arizona, and Lamy, New Mexico previously referred to R. callenderi pertain to a new spe­ cies, named Revueltosaurus hunti here. R. hunti is more derived than R. callenderi and is one of the most derived Triassic ornithischians. However, detailed biostratigraphy indicates that R. hunti is older (Adamanian: latest Carnian) than R. callenderi (Revueltian: early-mid Norian). Both taxa have great potential as index taxa of their respective faunachrons and support existing biochronologies based on other tetrapods, megafossil plants, palynostratigraphy, and lithostratigraphy.
    [Show full text]
  • 01 Oliveira & Pinheiro RBP V20 N2 COR.Indd
    Rev. bras. paleontol. 20(2):155-162, Maio/Agosto 2017 © 2017 by the Sociedade Brasileira de Paleontologia doi: 10.4072/rbp.2017.2.01 ISOLATED ARCHOSAURIFORM TEETH FROM THE UPPER TRIASSIC CANDELÁRIA SEQUENCE (HYPERODAPEDON ASSEMBLAGE ZONE, SOUTHERN BRAZIL) TIANE MACEDO DE OLIVEIRA & FELIPE L. PINHEIRO Laboratório de Paleobiologia, Universidade Federal do Pampa, Campus São Gabriel, R. Aluízio Barros Macedo, BR 290, km 423, 97300-000, São Gabriel, RS, Brazil. [email protected], [email protected] ABSTRACT – We describe isolated teeth found in the locality “Sítio Piveta” (Hyperodapedon Assemblage Zone, Candelaria Sequence, Upper Triassic of the Paraná Basin). The material consists of five specimens, here classified into three different morphotypes. The morphotype I is characterized by pronounced elongation, rounded base and symmetry between lingual and labial surfaces. The morphotype II presents serrated mesial and distal edges, mesial denticles decreasing in size toward the base, distal denticles present until the base and asymmetry, with a flat lingual side and rounded labial side. The morphotype III, although similar to morphotype II, has a greater inclination of the posterior carinae. The conservative dental morphology in Archosauriformes makes difficult an accurate taxonomic assignment based only on isolated teeth. However, the specimens we present are attributable to “Rauisuchia” (morphotype II and III) and, possibly, Phytosauria (morphotype I). The putative presence of a phytosaur in the Carnian Hyperodapedon Assemblage Zone would have impact in the South American distribution of the group. The taxonomic assignments proposed herein contribute to the faunal composition of the Hyperodapedon Assemblage Zone, a critical unit on the study of the Upper Triassic radiation of archosaurs.
    [Show full text]
  • On the Presence of the Subnarial Foramen in Prestosuchus Chiniquensis (Pseudosuchia: Loricata) with Remarks on Its Phylogenetic Distribution
    Anais da Academia Brasileira de Ciências (2016) (Annals of the Brazilian Academy of Sciences) Printed version ISSN 0001-3765 / Online version ISSN 1678-2690 http://dx.doi.org/10.1590/0001-3765201620150456 www.scielo.br/aabc On the presence of the subnarial foramen in Prestosuchus chiniquensis (Pseudosuchia: Loricata) with remarks on its phylogenetic distribution LÚCIO ROBERTO-DA-SILVA1,2, MARCO A.G. FRANÇA3, SÉRGIO F. CABREIRA3, RODRIGO T. MÜLLER1 and SÉRGIO DIAS-DA-SILVA4 ¹Programa de Pós-Graduação em Biodiversidade Animal, Universidade Federal de Santa Maria, Av. Roraima, 1000, Bairro Camobi, 97105-900 Santa Maria, RS, Brasil ²Laboratório de Paleontologia, Universidade Luterana do Brasil, Av. Farroupilha, 8001, Bairro São José, 92425-900 Canoas, RS, Brasil ³Laboratório de Paleontologia e Evolução de Petrolina, Campus de Ciências Agrárias, Universidade Federal do Vale do São Francisco, Rodovia BR 407, Km12, Lote 543, 56300-000 Petrolina, PE, Brasil 4Centro de Apoio à Pesquisa da Quarta Colônia, Universidade Federal de Santa Maria, Rua Maximiliano Vizzotto, 598, 97230-000 São João do Polêsine, RS, Brasil Manuscript received on July 1, 2015; accepted for publication on April 15, 2016 ABSTRACT Many authors have discussed the subnarial foramen in Archosauriformes. Here presence among Archosauriformes, shape, and position of this structure is reported and its phylogenetic importance is investigated. Based on distribution and the phylogenetic tree, it probably arose independently in Erythrosuchus, Herrerasaurus, and Paracrocodylomorpha. In Paracrocodylomorpha the subnarial foramen is oval-shaped, placed in the middle height of the main body of the maxilla, and does not reach the height of ascending process. In basal loricatans from South America (Prestosuchus chiniquensis and Saurosuchus galilei) the subnarial foramen is ‘drop-like’ shaped, the subnarial foramen is located above the middle height of the main body of the maxilla, reaching the height of ascending process, a condition also present in Herrerasaurus ischigualastensis.
    [Show full text]
  • And Early Jurassic Sediments, and Patterns of the Triassic-Jurassic
    and Early Jurassic sediments, and patterns of the Triassic-Jurassic PAUL E. OLSEN AND tetrapod transition HANS-DIETER SUES Introduction parent answer was that the supposed mass extinc- The Late Triassic-Early Jurassic boundary is fre- tions in the tetrapod record were largely an artifact quently cited as one of the thirteen or so episodes of incorrect or questionable biostratigraphic corre- of major extinctions that punctuate Phanerozoic his- lations. On reexamining the problem, we have come tory (Colbert 1958; Newell 1967; Hallam 1981; Raup to realize that the kinds of patterns revealed by look- and Sepkoski 1982, 1984). These times of apparent ing at the change in taxonomic composition through decimation stand out as one class of the great events time also profoundly depend on the taxonomic levels in the history of life. and the sampling intervals examined. We address Renewed interest in the pattern of mass ex- those problems in this chapter. We have now found tinctions through time has stimulated novel and com- that there does indeed appear to be some sort of prehensive attempts to relate these patterns to other extinction event, but it cannot be examined at the terrestrial and extraterrestrial phenomena (see usual coarse levels of resolution. It requires new fine- Chapter 24). The Triassic-Jurassic boundary takes scaled documentation of specific faunal and floral on special significance in this light. First, the faunal transitions. transitions have been cited as even greater in mag- Stratigraphic correlation of geographically dis- nitude than those of the Cretaceous or the Permian junct rocks and assemblages predetermines our per- (Colbert 1958; Hallam 1981; see also Chapter 24).
    [Show full text]
  • New Insights on Prestosuchus Chiniquensis Huene
    New insights on Prestosuchus chiniquensis Huene, 1942 (Pseudosuchia, Loricata) based on new specimens from the “Tree Sanga” Outcrop, Chiniqua´ Region, Rio Grande do Sul, Brazil Marcel B. Lacerda1, Bianca M. Mastrantonio1, Daniel C. Fortier2 and Cesar L. Schultz1 1 Instituto de Geocieˆncias, Laborato´rio de Paleovertebrados, Universidade Federal do Rio Grande do Sul–UFRGS, Porto Alegre, Rio Grande do Sul, Brazil 2 CHNUFPI, Campus Amı´lcar Ferreira Sobral, Universidade Federal do Piauı´, Floriano, Piauı´, Brazil ABSTRACT The ‘rauisuchians’ are a group of Triassic pseudosuchian archosaurs that displayed a near global distribution. Their problematic taxonomic resolution comes from the fact that most taxa are represented only by a few and/or mostly incomplete specimens. In the last few decades, renewed interest in early archosaur evolution has helped to clarify some of these problems, but further studies on the taxonomic and paleobiological aspects are still needed. In the present work, we describe new material attributed to the ‘rauisuchian’ taxon Prestosuchus chiniquensis, of the Dinodontosaurus Assemblage Zone, Middle Triassic (Ladinian) of the Santa Maria Supersequence of southern Brazil, based on a comparative osteologic analysis. Additionally, we present well supported evidence that these represent juvenile forms, due to differences in osteological features (i.e., a subnarial fenestra) that when compared to previously described specimens can be attributed to ontogeny and indicate variation within a single taxon of a problematic but important
    [Show full text]
  • Magnetostratigraphy of the Upper Triassic Chinle Group of New Mexico: Implications for Regional and Global Correlations Among Upper Triassic Sequences
    Magnetostratigraphy of the Upper Triassic Chinle Group of New Mexico: Implications for regional and global correlations among Upper Triassic sequences Kate E. Zeigler1,* and John W. Geissman2,* 1Department of Earth and Planetary Sciences, MSC 03-2040 Northrop Hall, University of New Mexico, Albuquerque, New Mexico 87131, USA 2Department of Earth and Planetary Sciences, MSC 03-2040 Northrop Hall, University of New Mexico, Albuquerque, New Mexico 87131, USA, and Department of Geosciences, ROC 21, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080-3021, USA ABSTRACT polarity chronologies from upper Chinle graphic correlations (e.g., Reeve, 1975; Reeve and strata in New Mexico and Utah suggest that Helsley, 1972; Bazard and Butler, 1989, 1991; A magnetic polarity zonation for the strata considered to be part of the Rock Point Molina-Garza et al., 1991, 1993, 1996, 1998a, Upper Triassic Chinle Group in the Chama Formation in north-central New Mexico are 1998b, 2003; Steiner and Lucas, 2000). Conse- Basin, north-central New Mexico (United not time equivalent to type Rock Point strata quently, the polarity record of the mudstones and States), supplemented by polarity data from in Utah or to the Redonda Formation of east- claystones, which are the principal rock types in eastern and west-central New Mexico (Mesa ern New Mexico. the Chinle Group, is largely unknown. Redonda and Zuni Mountains, respectively), In our study of Triassic strata in the Chama provides the most complete and continuous INTRODUCTION Basin of north-central New Mexico, we sam- magnetic polarity chronology for the Late pled all components of the Chinle Group, with Triassic of the American Southwest yet avail- The Upper Triassic Chinle Group, prominent a focus on mudstones and claystones at Coyote able.
    [Show full text]