The Smallest Biggest Theropod Dinosaur: a Tiny Pedal Ungual of a Juvenile Spinosaurus from the Cretaceous of Morocco
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Fused and Vaulted Nasals of Tyrannosaurid Dinosaurs: Implications for Cranial Strength and Feeding Mechanics
Fused and vaulted nasals of tyrannosaurid dinosaurs: Implications for cranial strength and feeding mechanics ERIC SNIVELY, DONALD M. HENDERSON, and DOUG S. PHILLIPS Snively, E., Henderson, D.M., and Phillips, D.S. 2006. Fused and vaulted nasals of tyrannosaurid dinosaurs: Implications for cranial strength and feeding mechanics. Acta Palaeontologica Polonica 51 (3): 435–454. Tyrannosaurid theropods display several unusual adaptations of the skulls and teeth. Their nasals are fused and vaulted, suggesting that these elements braced the cranium against high feeding forces. Exceptionally high strengths of maxillary teeth in Tyrannosaurus rex indicate that it could exert relatively greater feeding forces than other tyrannosaurids. Areas and second moments of area of the nasals, calculated from CT cross−sections, show higher nasal strengths for large tyrannosaurids than for Allosaurus fragilis. Cross−sectional geometry of theropod crania reveals high second moments of area in tyrannosaurids, with resulting high strengths in bending and torsion, when compared with the crania of similarly sized theropods. In tyrannosaurids trends of strength increase are positively allomeric and have similar allometric expo− nents, indicating correlated progression towards unusually high strengths of the feeding apparatus. Fused, arched nasals and broad crania of tyrannosaurids are consistent with deep bites that impacted bone and powerful lateral movements of the head for dismembering prey. Key words: Theropoda, Carnosauria, Tyrannosauridae, biomechanics, feeding mechanics, computer modeling, com− puted tomography. Eric Snively [[email protected]], Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada; Donald M. Henderson [[email protected]], Royal Tyrrell Museum of Palaeontology, Box 7500, Drumheller, Alberta T0J 0Y0, Canada; Doug S. -
Late Jurassic Theropod Dinosaur Bones from the Langenberg Quarry
Late Jurassic theropod dinosaur bones from the Langenberg Quarry (Lower Saxony, Germany) provide evidence for several theropod lineages in the central European archipelago Serjoscha W. Evers1 and Oliver Wings2 1 Department of Geosciences, University of Fribourg, Fribourg, Switzerland 2 Zentralmagazin Naturwissenschaftlicher Sammlungen, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany ABSTRACT Marine limestones and marls in the Langenberg Quarry provide unique insights into a Late Jurassic island ecosystem in central Europe. The beds yield a varied assemblage of terrestrial vertebrates including extremely rare bones of theropod from theropod dinosaurs, which we describe here for the first time. All of the theropod bones belong to relatively small individuals but represent a wide taxonomic range. The material comprises an allosauroid small pedal ungual and pedal phalanx, a ceratosaurian anterior chevron, a left fibula of a megalosauroid, and a distal caudal vertebra of a tetanuran. Additionally, a small pedal phalanx III-1 and the proximal part of a small right fibula can be assigned to indeterminate theropods. The ontogenetic stages of the material are currently unknown, although the assignment of some of the bones to juvenile individuals is plausible. The finds confirm the presence of several taxa of theropod dinosaurs in the archipelago and add to our growing understanding of theropod diversity and evolution during the Late Jurassic of Europe. Submitted 13 November 2019 Accepted 19 December 2019 Subjects Paleontology, -
BGS Report, Single Column Layout
1 The Cretaceous Continental Intercalaire in central Algeria: subsurface evidence for a fluvial to aeolian 2 transition and implications for the onset of aridity on the Saharan Platform 3 A.J. Newella*, G.A. Kirbyb, J.P.R. Sorensena, A.E. Milodowskib 4 a British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK, email: [email protected] 5 b British Geological Survey, Nicker Hill, Keyworth, Nottingham, NG12 5GG, UK 6 * Corresponding author 7 Abstract 8 The Lower Cretaceous Continental Intercalaire of North Africa is a terrestrial to shallow marine 9 continental wedge deposited along the southern shoreline of the Neotethys Ocean. Today it has a wide 10 distribution across the northern Sahara where it has enormous socio-economic importance as a major 11 freshwater aquifer. During the Early Cretaceous major north-south trending basement structures were 12 reactivated in response to renewed Atlantic rifting and in Algeria, faults along the El Biod-Hassi 13 Messaourd Ridge appear to have been particularly important in controlling thickness patterns of the 14 Lower Cretaceous Continental Intercalaire. Subsurface data from the Krechba gas field in Central Algeria 15 shows that the Lower Cretaceous stratigraphy is subdivided into two clear parts. The lower part (here 16 termed the In Salah Formation) is a 200 m thick succession of alluvial deposits with large meandering 17 channels, clearly shown in 3D seismic, and waterlogged flood basins indicated by lignites and gleyed, 18 pedogenic mudstones. The overlying Krechba Formation is a 500 m thick succession of quartz- 19 dominated sands and sandstones whose microstructure indicates an aeolian origin, confirming earlier 20 observations from outcrop. -
Evaluating the Ecology of Spinosaurus: Shoreline Generalist Or Aquatic Pursuit Specialist?
Palaeontologia Electronica palaeo-electronica.org Evaluating the ecology of Spinosaurus: Shoreline generalist or aquatic pursuit specialist? David W.E. Hone and Thomas R. Holtz, Jr. ABSTRACT The giant theropod Spinosaurus was an unusual animal and highly derived in many ways, and interpretations of its ecology remain controversial. Recent papers have added considerable knowledge of the anatomy of the genus with the discovery of a new and much more complete specimen, but this has also brought new and dramatic interpretations of its ecology as a highly specialised semi-aquatic animal that actively pursued aquatic prey. Here we assess the arguments about the functional morphology of this animal and the available data on its ecology and possible habits in the light of these new finds. We conclude that based on the available data, the degree of adapta- tions for aquatic life are questionable, other interpretations for the tail fin and other fea- tures are supported (e.g., socio-sexual signalling), and the pursuit predation hypothesis for Spinosaurus as a “highly specialized aquatic predator” is not supported. In contrast, a ‘wading’ model for an animal that predominantly fished from shorelines or within shallow waters is not contradicted by any line of evidence and is well supported. Spinosaurus almost certainly fed primarily from the water and may have swum, but there is no evidence that it was a specialised aquatic pursuit predator. David W.E. Hone. Queen Mary University of London, Mile End Road, London, E1 4NS, UK. [email protected] Thomas R. Holtz, Jr. Department of Geology, University of Maryland, College Park, Maryland 20742 USA and Department of Paleobiology, National Museum of Natural History, Washington, DC 20560 USA. -
Implications for Predatory Dinosaur Macroecology and Ontogeny in Later Late Cretaceous Asiamerica
Canadian Journal of Earth Sciences Theropod Guild Structure and the Tyrannosaurid Niche Assimilation Hypothesis: Implications for Predatory Dinosaur Macroecology and Ontogeny in later Late Cretaceous Asiamerica Journal: Canadian Journal of Earth Sciences Manuscript ID cjes-2020-0174.R1 Manuscript Type: Article Date Submitted by the 04-Jan-2021 Author: Complete List of Authors: Holtz, Thomas; University of Maryland at College Park, Department of Geology; NationalDraft Museum of Natural History, Department of Geology Keyword: Dinosaur, Ontogeny, Theropod, Paleocology, Mesozoic, Tyrannosauridae Is the invited manuscript for consideration in a Special Tribute to Dale Russell Issue? : © The Author(s) or their Institution(s) Page 1 of 91 Canadian Journal of Earth Sciences 1 Theropod Guild Structure and the Tyrannosaurid Niche Assimilation Hypothesis: 2 Implications for Predatory Dinosaur Macroecology and Ontogeny in later Late Cretaceous 3 Asiamerica 4 5 6 Thomas R. Holtz, Jr. 7 8 Department of Geology, University of Maryland, College Park, MD 20742 USA 9 Department of Paleobiology, National Museum of Natural History, Washington, DC 20013 USA 10 Email address: [email protected] 11 ORCID: 0000-0002-2906-4900 Draft 12 13 Thomas R. Holtz, Jr. 14 Department of Geology 15 8000 Regents Drive 16 University of Maryland 17 College Park, MD 20742 18 USA 19 Phone: 1-301-405-4084 20 Fax: 1-301-314-9661 21 Email address: [email protected] 22 23 1 © The Author(s) or their Institution(s) Canadian Journal of Earth Sciences Page 2 of 91 24 ABSTRACT 25 Well-sampled dinosaur communities from the Jurassic through the early Late Cretaceous show 26 greater taxonomic diversity among larger (>50kg) theropod taxa than communities of the 27 Campano-Maastrichtian, particularly to those of eastern/central Asia and Laramidia. -
The Continental Intercalaire Aquifer at the Kébili Geothermal Field, Southern Tunisia
Proceedings World Geothermal Congress 2005 Antalya, Turkey, 24-29 April 2005 The Continental Intercalaire Aquifer at the Kébili Geothermal Field, Southern Tunisia Aissa Agoun Regional Commissariat for Agricultural Development Water Resources Departement, C.R.D.A Kébili, Kébili 4200, TUNISIA [email protected] Keywords: CI, Kébili, wells, artesian wellheads like valves and monitoring points. Also drawdown of the water level has been observed due to the ABSTRACT increasing water demands. Radiocarbon analysis has shown that radiocarbon is present at between 2 and 10 pmc which The C.I. "Continental Intercalaire" aquifer is an extensive leads to the conclusion that the water is recharged during horizontal sandstone reservoir (Neocomien: Lower the late Pleistocene 25,000 years B.P, corresponding to the Cretaceous: Purbecko-Wealdien). The CI is one of the last glaciation (Edmonds et al., 1997). Water is fossil and largest aquifers in the world covering more than 1 million 2 without actual recharge, so to preserve the trans-borderers km in Tunisia, Algeria and Libya. This aquifer covers reservoir, more research must be carried out on the aquifer. 80,000 km2 in Tunisia Full collaboration with Algerian and Libyan organizations In Kébili field in southern Tunisia, the geothermal water is is necessary in order to achieve economical and sustainable about 25 to 50 thousand years old and of sulphate chlorite future production and regional development. Long term type. The depth of the reservoir ranges from 1000 to 2800 monitoring of pressure temperature and salinity at the m. wellhead for each production well should be carried out. Any increase of drawdown during the next 20 years caused The piézométric level is about 200 meters above the by increased production will lead to environmental changes. -
Cranial Anatomy of Allosaurus Jimmadseni, a New Species from the Lower Part of the Morrison Formation (Upper Jurassic) of Western North America
Cranial anatomy of Allosaurus jimmadseni, a new species from the lower part of the Morrison Formation (Upper Jurassic) of Western North America Daniel J. Chure1,2,* and Mark A. Loewen3,4,* 1 Dinosaur National Monument (retired), Jensen, UT, USA 2 Independent Researcher, Jensen, UT, USA 3 Natural History Museum of Utah, University of Utah, Salt Lake City, UT, USA 4 Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA * These authors contributed equally to this work. ABSTRACT Allosaurus is one of the best known theropod dinosaurs from the Jurassic and a crucial taxon in phylogenetic analyses. On the basis of an in-depth, firsthand study of the bulk of Allosaurus specimens housed in North American institutions, we describe here a new theropod dinosaur from the Upper Jurassic Morrison Formation of Western North America, Allosaurus jimmadseni sp. nov., based upon a remarkably complete articulated skeleton and skull and a second specimen with an articulated skull and associated skeleton. The present study also assigns several other specimens to this new species, Allosaurus jimmadseni, which is characterized by a number of autapomorphies present on the dermal skull roof and additional characters present in the postcrania. In particular, whereas the ventral margin of the jugal of Allosaurus fragilis has pronounced sigmoidal convexity, the ventral margin is virtually straight in Allosaurus jimmadseni. The paired nasals of Allosaurus jimmadseni possess bilateral, blade-like crests along the lateral margin, forming a pronounced nasolacrimal crest that is absent in Allosaurus fragilis. Submitted 20 July 2018 Accepted 31 August 2019 Subjects Paleontology, Taxonomy Published 24 January 2020 Keywords Allosaurus, Allosaurus jimmadseni, Dinosaur, Theropod, Morrison Formation, Jurassic, Corresponding author Cranial anatomy Mark A. -
A Century of Spinosaurs - a Review and Revision of the Spinosauridae
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Queen Mary Research Online A century of spinosaurs - a review and revision of the Spinosauridae with comments on their ecology HONE David William Elliott1, * HOLTZ Thomas Richard Jnr2 1 School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK 2 Department of Geology, University of Maryland, College Park, MD 20742 USA Abstract: The spinosaurids represent an enigmatic and highly unusual form of large tetanuran theropods that were first identified in 1915. A recent flurry of discoveries and taxonomic revisions of this important and interesting clade had added greatly to our knowledge, however, spinosaur body fossils are generally rare and most species are known from only limited skeletal remains. Their unusual anatomical adaptations to the skull, limbs and axial column all differ from other large theropods and point to an unusual ecological niche and a lifestyle intimately linked to water. Keywords: Theropoda, Megalosauroidea, Baryonychinae, Spinosaurinae, palaeoecology E-mail: [email protected] 1 Introduction The Spinosauridae is an enigmatic clade of large and carnivorous theropods from the Jurassic and Cretaceous that are known from both Gondwana and Laurasia (Holtz et al., 2004). Despite their wide temporal and geographic distribution, the clade is known primarily from teeth and the body fossil record is extremely limited (Bertin, 2010). As such, relatively little is known about this group of animals, although their unusual morphology with regard to skull shape, dentition, dorsal neural spines and other features mark them out as divergent from the essential bauplan of other non-tetanuran theropods (Fig 1). -
Dinosaurs of Portugal Dinosaures Du Portugal
C. R. Palevol 2 (2003) 77–95 Systematic Palaeontology / Paléontologie systématique (Vertebrate Palaeontology / Paléontologie des Vertébrés) Dinosaurs of Portugal Dinosaures du Portugal Miguel Telles Antunes a,b,c,d, Octávio Mateus c,d,* a Academia de Ciências de Lisboa, Portugal b European Academy of Sciences and Humanities, 60, rue Monsieur-le-Prince, 75006 Paris, France c Centro de Estudos Geológicos, Faculdade de Ciências e Tecnologia (UNL)/Quinta da Torre, 2829-516 Caparica, Portugal d GEAL - Museu da Lourinhã, 2530 Lourinhã, Portugal Accepted 6 January 2003 Written on invitation of the Editorial Board Abstract A synthesis on the state of art on dinosaur knowledge in Portugal is presented. The following genera have been recognized: Ceratosaurus, Torvosaurus, Lourinhanosaurus, Allosaurus, cf. Compsognathus, Stokesosaurus, cf. Richardoestesia, cf. Archaeopteryx, Euronychodon, cf. Paronychodon, Dinheirosaurus, Lourinhasaurus, Lusotitan, cf. Pleurocoelus, Lusitanosau- rus, Dacentrurus, Dracopelta, Phyllodon, Hypsilophodon, Alocodon, Trimucrodon, Draconyx, Iguanodon, and Taveirosaurus. Most are from Late Jurassic localities at the Lourinhã area and Guimarota. A new genus, Lusotitan, is here raised to include the Late Jurassic ‘Brachiosaurus’atalaiensis. Lower Cretaceous until Cenomanian material is scarce, except for dinosaur footprints. An interesting Late-Cretaceous, mostly small dinosaur association has been collected between Aveiro and Taveiro. To cite this article: M.T. Antunes, O. Mateus, C. R. Palevol 2 (2003) 77–95. © 2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. Résumé On présente une synthèse concernant l’état actuel des connaissances sur les dinosaures du Portugal. Les genres suivants ont été reconnus : Ceratosaurus, Torvosaurus, Lourinhanosaurus, Allosaurus, cf. Compsognathus, Stokesosaurus, cf. Richardoes- tesia, cf. Archaeopteryx, Euronychodon, cf. Paronychodon, Dinheirosaurus, Lourinhasaurus, Lusotitan, cf. -
The Dinosaur Field Guide Supplement
The Dinosaur Field Guide Supplement September 2010 – December 2014 By, Zachary Perry (ZoPteryx) Page 1 Disclaimer: This supplement is intended to be a companion for Gregory S. Paul’s impressive work The Princeton Field Guide to Dinosaurs, and as such, exhibits some similarities in format, text, and taxonomy. This was done solely for reasons of aesthetics and consistency between his book and this supplement. The text and art are not necessarily reflections of the ideals and/or theories of Gregory S. Paul. The author of this supplement was limited to using information that was freely available from public sources, and so more information may be known about a given species then is written or illustrated here. Should this information become freely available, it will be included in future supplements. For genera that have been split from preexisting genera, or when new information about a genus has been discovered, only minimal text is included along with the page number of the corresponding entry in The Princeton Field Guide to Dinosaurs. Genera described solely from inadequate remains (teeth, claws, bone fragments, etc.) are not included, unless the remains are highly distinct and cannot clearly be placed into any other known genera; this includes some genera that were not included in Gregory S. Paul’s work, despite being discovered prior to its publication. All artists are given full credit for their work in the form of their last name, or lacking this, their username, below their work. Modifications have been made to some skeletal restorations for aesthetic reasons, but none affecting the skeleton itself. -
Quantifying Paleorecharge in the Continental Intercalaire (CI) Aquifer by a Monte-Carlo Inversion Approach of 36Cl=Cl Data ⇑ J.O
Applied Geochemistry 50 (2014) 209–221 Contents lists available at ScienceDirect Applied Geochemistry journal homepage: www.elsevier.com/locate/apgeochem Quantifying paleorecharge in the Continental Intercalaire (CI) aquifer by a Monte-Carlo inversion approach of 36Cl=Cl data ⇑ J.O. Petersen a, , P. Deschamps a,b, J. Gonçalvès a,c, B. Hamelin a,c, J.L. Michelot d, A. Guendouz e, K. Zouari f a Aix-Marseille Univ., CEREGE, Aix-en-Provence, France b IRD, CEREGE, Aix-en-Provence, France c CNRS, CEREGE, Aix-en-Provence, France d CNRS-UPS, IDES, Orsay, France e University of Blida, Blida, Algeria f ENIS, Sfax, Tunisia article info abstract Article history: Past variations of the recharge is estimated in the Atlas Mountains, the main recharge area of the Available online 5 May 2014 Continental Intercalaire (CI) aquifer, one of the major Saharan aquifers, over the last 775 kyr. In this Mediterranean climatic context, continental archives generally record single humid events, grouped in hypothetical time interval and do not offer continuous chronicles of precipitation. We propose to use spa- tially distributed 36Cl=Cl data as a temporal constraint, to infer the past recharge in the Atlas area. Based on a simplified but robust climatic scenario, assuming a piston model, we apply a Markov Chain Monte Carlo (MCMC) inversion approach to attribute a specific recharge to the last nine interglacial periods and an undifferentiated recharge to the glacial periods. The interglacial recharge values vary from a few mm yrÀ1 to more than 60 mm yrÀ1. Glacial recharge is less than 1 mm yrÀ1. These values are then ana- lyzed in terms of intensity and allow questioning some initial hypothesis, especially the generally accepted value of the initial 36Cl=Cl value (around 133 Â 10À15 at atÀ1). -
VARIAÇÃO MORFOLÓGICA EM DENTES ROSTRAIS DO ESPADARTE EXTINTO Atlanticopristis Equatorialis PEREIRA & MEDEIROS, 2008
BOLETIM DO LABORATÓRIO DE HIDROBIOLOGIA Vol. 30: 25-32, 2020 Publicado em janeiro 2020 Bol. Lab. Hidrobiol. VARIAÇÃO MORFOLÓGICA EM DENTES ROSTRAIS DO ESPADARTE EXTINTO Atlanticopristis equatorialis PEREIRA & MEDEIROS, 2008 Lays S. de Oliveira Silva1, Jorge L. S. Nunes2 & Manuel Alfredo Medeiros3 1 Centro de Pesquisa de História Natural e Arqueologia do Maranhão, Rua do Giz 59, Praia Grande, CEP 65010-680, São Luís, MA, Brasil. 2 Universidade Federal do Maranhão, Departamento de Oceanografi a e Limnologia. Avenida dos Portugueses 1966, Cidade Universitária do Bacanga, CEP 65080-805, São Luís, MA, Brasil. 3 Universidade Federal do Maranhão, Departamento de Biologia. Avenida dos Portugueses 1966, Cidade Universitária do Bacanga, CEP 65080-805, São Luís, MA, Brasil. RESUMO As raias-espadarte Esclerorhynchidae (Batoidea) fazem parte de um grupo extinto monofi lético que é bem registrado no Cretáceo. Para avaliar a variação morfológica intraespecífi ca de uma espécie do Cretáceo, os dentes rostrais referidos a Atlanticopristis equatorialis Pereira & Medeiros, 2008 foram analisados e seus caracteres morfológicos medidos e comparados. A coroa dos dentes rostrais exibe margens anterior e posterior multidenticuladas (2 a 5 farpas em cada margem). Em algumas amostras, pequenas protuberâncias próximas à base podem ser consideradas dentículos (farpas) vestigiais. Nervuras enameloides (costelas) extensas são vistas nas superfícies dorsal e ventral da coroa; as costelas centralizadas são paralelas e confi nadas à porção mais proximal da coroa, com as periféricas formando ângulos progressivamente maiores em relação ao eixo longitudinal do dente, resultando em uma aparência de leque. Foi observada uma variação de 6 a 13 costelas. A variação observada no pedúnculo é menos útil em relação à taxonomia, uma vez que serve como uma “raiz” para os dentes e muitos padrões diferentes de superfícies rugosas podem ser fi xados por ligamentos.