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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. -
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. -
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. -
Tooth Enamel Microstructure of Revueltosaurus
Palaeontologia Electronica palaeo-electronica.org Tooth enamel microstructure of Revueltosaurus and Krzyzanowskisaurus (Reptilia:Archosauria) from the Upper Triassic Chinle Group, USA: Implications for function, growth, and phylogeny Andrew B. Heckert and Jessica A. Miller-Camp ABSTRACT Tooth enamel microstructure can carry significant phylogenetic, ontogenetic, and functional information within amniotes. Here we provide the first descriptions of the tooth enamel microstructure of two Late Triassic taxa, the crurotarsan Revueltosaurus callenderi Hunt and the putative ornithischian Krzyzanowskisaurus hunti (Heckert), which some consider closely related. To test the hypotheses that enamel thickness corresponds to function and/or phylogeny we analyzed the enamel of each at various scales, measuring enamel thickness and examining microstructural features through- out both longitudinal and cross-sectional thickness using previously established tech- niques to facilitate comparisons. Both taxa possess thick (up to ~150 µm) enamel for their size (< 20 mm crown height). Enamel in R. callenderi ranged from ~5-152 µm across a premaxillary tooth in longitudinal section, and ~42-92 µm in a maxillary/den- tary tooth transverse section. K. hunti enamel thickness was ~18-155 µm longitudinally and ~29-75 µm transversely. Both also had well-developed basal unit layers (BUL) and weakly developed columnar microstructure. Well-developed lines of incremental growth (LIG) are present in both taxa, through which the columnar enamel grades into parallel crystallite enamel. Their enamel microstructure is therefore grossly similar to that of several ornithischian taxa, especially ankylosaurs, with which they are strongly convergent, and also compares well to rauisuchids and tyrannosaurids. The relatively unique combination of microstructural characteristics in the schmelzmuster of R. -
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. -
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 -
Heptasuchus Clarki, from the ?Mid-Upper Triassic, Southeastern Big Horn Mountains, Central Wyoming (USA)
The osteology and phylogenetic position of the loricatan (Archosauria: Pseudosuchia) Heptasuchus clarki, from the ?Mid-Upper Triassic, southeastern Big Horn Mountains, Central Wyoming (USA) † Sterling J. Nesbitt1, John M. Zawiskie2,3, Robert M. Dawley4 1 Department of Geosciences, Virginia Tech, Blacksburg, VA, USA 2 Cranbrook Institute of Science, Bloomfield Hills, MI, USA 3 Department of Geology, Wayne State University, Detroit, MI, USA 4 Department of Biology, Ursinus College, Collegeville, PA, USA † Deceased author. ABSTRACT Loricatan pseudosuchians (known as “rauisuchians”) typically consist of poorly understood fragmentary remains known worldwide from the Middle Triassic to the end of the Triassic Period. Renewed interest and the discovery of more complete specimens recently revolutionized our understanding of the relationships of archosaurs, the origin of Crocodylomorpha, and the paleobiology of these animals. However, there are still few loricatans known from the Middle to early portion of the Late Triassic and the forms that occur during this time are largely known from southern Pangea or Europe. Heptasuchus clarki was the first formally recognized North American “rauisuchian” and was collected from a poorly sampled and disparately fossiliferous sequence of Triassic strata in North America. Exposed along the trend of the Casper Arch flanking the southeastern Big Horn Mountains, the type locality of Heptasuchus clarki occurs within a sequence of red beds above the Alcova Limestone and Crow Mountain formations within the Chugwater Group. The age of the type locality is poorly constrained to the Middle—early Late Triassic and is Submitted 17 June 2020 Accepted 14 September 2020 likely similar to or just older than that of the Popo Agie Formation assemblage from Published 27 October 2020 the western portion of Wyoming. -
A Giant Phytosaur (Reptilia: Archosauria) Skull from the Redonda Formation (Upper Triassic: Apachean) of East-Central New Mexico
New Mexico Geological Society Guidebook, 52 nd Field Conference, Geology of the LlallO Estacado, 2001 169 A GIANT PHYTOSAUR (REPTILIA: ARCHOSAURIA) SKULL FROM THE REDONDA FORMATION (UPPER TRIASSIC: APACHEAN) OF EAST-CENTRAL NEW MEXICO ANDREW B. HECKERT ', SPENCER G. LUCAS', ADRJAN P. HUNT' AND JERALD D. HARRlS' 'Department of Earth and Planetary Sciences, University of New Me~ico, Albuquerque, NM 87131- 1116; INcw Me~ico Museum of Natural History and Science, 1801 Mountain Rd NW, Albuquerque, 87104; lMesalands Dinosaur Museum, Mesa Technical Coll ege, 911 South Tenth Street, Tucumcari, NM 88401; ' Department of Earth and Environmental Sciences, University of Pennsylvania, Philadelphia, PA 19104 Abslr.cl.-In the Sum!Mr of 1994, a field party of the New Mexico Museum of Natural History and Science (NMMNH) collected a giant, incomplete phytosaur skull from a bonebed discovered by Paul Sealey in east-central New Me~ieo. This bonebed lies in a narrow channcl deposit of intrafonnational conglomerate in the Redonda Fonnation. Stratigraphically, this specimen comes from strata identical to the type Apachean land·vertebrate faunachron and thus of Apachean (latest Triassic: latc Norian·Rhaetian) age. The skull lacks most of the snout but is otherwise complete and in excellent condition. As preserved, the skull measures 780 mm long, and was probably 1200 mm or longer in life, making it nearly as large as the holotype of Ru{iodon (- lIfaehaeroprosoprls . ..Smilwlldllls) gngorii, and one of the largest published phytosallr sku ll s. The diagnostic features of Redondasall'us present in the skull include robnst squamosal bars extending posteriorly well beyond the occiput and supratemporal fenestrae that are completely concealed in dorsal view. -
A New Phylogenetic Analysis of Phytosauria (Archosauria: Pseudosuchia) with the Application of Continuous and Geometric Morphometric Character Coding
A new phylogenetic analysis of Phytosauria (Archosauria: Pseudosuchia) with the application of continuous and geometric morphometric character coding Andrew S. Jones and Richard J. Butler School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK ABSTRACT Phytosauria is a clade of large, carnivorous, semi-aquatic archosauromorphs which reached its peak diversity and an almost global distribution in the Late Triassic (c. 230–201 Mya). Previous phylogenetic analyses of Phytosauria have either focused primarily on the relationships of specific subclades, or were limited in taxonomic scope, and no taxonomically comprehensive dataset is currently available. We here present the most taxonomically comprehensive cladistic dataset of phytosaurs to date, based on extensive first-hand study, identification of novel characters and synthesis of previous matrices. This results in an almost twofold increase in phylogenetic information scored per taxon over previous analyses. Alongside a traditional discrete character matrix, three variant matrices were analysed in which selected characters were coded using continuous and landmarking methods, to more rigorously explore phytosaur relationships. Based on these four data matrices, four tree topologies were recovered. Relationships among non-leptosuchomorph phytosaurs are largely consistent between these four topologies, whereas those of more derived taxa are more variable. Rutiodon carolinensis consistently forms a sister relationship with Angistorhinus. In three topologies Nicrosaurus nests deeply within a group of traditionally Submitted 24 April 2018 non-Mystriosuchini taxa, leading us to redefine Mystriosuchini by excluding 9 October 2018 Accepted Nicrosaurus as an internal specifier. Two distinct patterns of relationships within Published 10 December 2018 Mystriosuchini are present in the four topologies, distinguished largely by the Corresponding author Andrew S. -
And Ornithomimid (Theropoda)
Supplementary information to Extreme convergence of the body plans of a suchian (Archosauria) and ornithomimid (Theropoda) dinosaurs. Sterling J. Nesbitt1,2 & Mark A. Norell1 1American Museum of Natural History, Central Park West at 79th Street, New York City, New York 10024, USA 2Lamont-Doherty Earth Observatory, Columbia University 61 Rt. 9W Palisades, New York 10964 USA 1. Phylogenetic analysis 2. Character list 3. Data Matrix 1. Phylogenetic analysis A modified version of Benton’s (1999) phylogentic analysis (see character list below) of basal archosaurs was used to test the relationships of Effigia. Parsimony analysis consisted of equally weighted heuristic searches with 100 random addition (RA) replicates and tree bisection and reconnection (TBR) branch-swapping run using PAUP* v4.0b10 (Swofford 2002). Nodal support was examined using nonparametric bootstrapping, with 1000 bootstrap replicates, TBR branch-swapping, and 10 RA sequences. Decay indices were calculated using TreeRot v2c (Sorenson 1999). A unique tree was recovered (20 taxa, 81 characters, characters weighted equally, unordered, tree length 156 steps, consistency index (CI) 0.5897, retention index (RI) 0.8320). The phylogenetic analysis finds Effigia and Shuvosaurus well supported within Suchia. The fully developed crocodile-normal ankle and crocodylomorph-like pes clearly places Effigia more closely related to crocodiles than to birds. Therefore, most of the ‘theropod-like’ characters that Effigia exhibits are convergent with dinosaurs, theropods, and other clades within Theropoda (see below). The placement of Effigia within Theropoda as a basal theropod requires the addition of twenty-seven steps and the placement sister to ornithomimids requires the addition of thirty steps. 2. Character list 1. -
Paleontology of the Bears Ears National Monument
Paleontology of Bears Ears National Monument (Utah, USA): history of exploration, study, and designation 1,2 3 4 5 Jessica Uglesich , Robert J. Gay *, M. Allison Stegner , Adam K. Huttenlocker , Randall B. Irmis6 1 Friends of Cedar Mesa, Bluff, Utah 84512 U.S.A. 2 University of Texas at San Antonio, Department of Geosciences, San Antonio, Texas 78249 U.S.A. 3 Colorado Canyons Association, Grand Junction, Colorado 81501 U.S.A. 4 Department of Integrative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53706 U.S.A. 5 University of Southern California, Los Angeles, California 90007 U.S.A. 6 Natural History Museum of Utah and Department of Geology & Geophysics, University of Utah, 301 Wakara Way, Salt Lake City, Utah 84108-1214 U.S.A. *Corresponding author: [email protected] or [email protected] Submitted September 2018 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.3442v2 | CC BY 4.0 Open Access | rec: 23 Sep 2018, publ: 23 Sep 2018 ABSTRACT Bears Ears National Monument (BENM) is a new, landscape-scale national monument jointly administered by the Bureau of Land Management and the Forest Service in southeastern Utah as part of the National Conservation Lands system. As initially designated in 2016, BENM encompassed 1.3 million acres of land with exceptionally fossiliferous rock units. Subsequently, in December 2017, presidential action reduced BENM to two smaller management units (Indian Creek and Shash Jáá). Although the paleontological resources of BENM are extensive and abundant, they have historically been under-studied. Here, we summarize prior paleontological work within the original BENM boundaries in order to provide a complete picture of the paleontological resources, and synthesize the data which were used to support paleontological resource protection. -
Associated Skeletons of a New Middle Triassic “Rauisuchia” from Brazil
Naturwissenschaften (2011) 98:389–395 DOI 10.1007/s00114-011-0782-3 ORIGINAL PAPER Associated skeletons of a new middle Triassic “Rauisuchia” from Brazil Marco Aurélio G. França & Jorge Ferigolo & Max C. Langer Received: 28 January 2011 /Revised: 3 March 2011 /Accepted: 4 March 2011 /Published online: 29 March 2011 # Springer-Verlag 2011 Abstract For more than 30 million years, in early Mesozoic Introduction Pangea, “rauisuchian” archosaurs were the apex predators in most terrestrial ecosystems, but their biology and evolu- “Rauisuchians” are a widespread group of crocodile-line tionary history remain poorly understood. We describe a new archosaurs, first recognized by Huene (1942), based on “rauisuchian” based on ten individuals found in a single fossils collected early in the last century by Gilherme Rau locality from the Middle Triassic (Ladinian) Santa Maria in the Middle Triassic of Rio Grande do Sul, southern Formation of southern Brazil. Nine articulated and associat- Brazil. Since then, the group has been also recorded in Late ed skeletons were discovered, three of which have nearly Triassic and possibly Early Triassic rocks in all major parts complete skulls. Along with sedimentological and tapho- of Pangea, except Australia and Antarctica (Gower 2000; nomic data, this suggests that those highly successful Brusatte et al. 2010). With estimated lengths of up to 8 m predators exhibited some kind of intraspecific interaction. (Barberena 1978;Bonaparte1981), “rauisuchians” are Other monotaxic assemblages of Triassic archosaurs are Late generally regarded as the top terrestrial predators of their Triassic (Norian-Rhaetian) in age, approximately 10 million ecosystems. They are usually considered to be quadrupedal, years younger than the material described here.