Evolutionary Pathways Toward Gigantism in Sharks and Rays
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Record of Carcharocles Megalodon in the Eastern
Estudios Geológicos julio-diciembre 2015, 71(2), e032 ISSN-L: 0367-0449 doi: http://dx.doi.org/10.3989/egeol.41828.342 Record of Carcharocles megalodon in the Eastern Guadalquivir Basin (Upper Miocene, South Spain) Registro de Carcharocles megalodon en el sector oriental de la Cuenca del Guadalquivir (Mioceno superior, Sur de España) M. Reolid, J.M. Molina Departamento de Geología, Universidad de Jaén, Campus Las Lagunillas sn, 23071 Jaén, Spain. Email: [email protected] / [email protected] ABSTRACT Tortonian diatomites of the San Felix Quarry (Porcuna), in the Eastern Guadalquivir Basin, have given isolated marine vertebrate remains that include a large shark tooth (123.96 mm from apex to the baseline of the root). The large size of the crown height (92.2 mm), the triangular shape, the broad serrated crown, the convex lingual face and flat labial face, and the robust, thick angled root determine that this specimen corresponds to Carcharocles megalodon. The symmetry with low slant shows it to be an upper anterior tooth. The total length estimated from the tooth crown height is calculated by means of different methods, and comparison is made with Carcharodon carcharias. The final inferred total length of around 11 m classifies this specimen in the upper size range of the known C. megalodon specimens. The palaeogeography of the Guadalquivir Basin close to the North Betic Strait, which connected the Atlantic Ocean to the Mediterranean Sea, favoured the interaction of the cold nutrient-rich Atlantic waters with warmer Mediterranean waters. The presence of diatomites indicates potential upwelling currents in this context, as well as high productivity favouring the presence of large vertebrates such as mysticetid whales, pinnipeds and small sharks (Isurus). -
Papers in Press
Papers in Press “Papers in Press” includes peer-reviewed, accepted manuscripts of research articles, reviews, and short notes to be published in Paleontological Research. They have not yet been copy edited and/or formatted in the publication style of Paleontological Research. As soon as they are printed, they will be removed from this website. Please note they can be cited using the year of online publication and the DOI, as follows: Humblet, M. and Iryu, Y. 2014: Pleistocene coral assemblages on Irabu-jima, South Ryukyu Islands, Japan. Paleontological Research, doi: 10.2517/2014PR020. doi:10.2517/2018PR013 Features and paleoecological significance of the shark fauna from the Upper Cretaceous Hinoshima Formation, Himenoura Group, Southwest Japan Accepted Naoshi Kitamura 4-8-7 Motoyama, Chuo-ku Kumamoto, Kumamoto 860-0821, Japan (e-mail: [email protected]) Abstract. The shark fauna of the Upper Cretaceous Hinoshima Formation (Santonian: 86.3–83.6 Ma) of the manuscriptHimenoura Group (Kamiamakusa, Kumamoto Prefecture, Kyushu, Japan) was investigated based on fossil shark teeth found at five localities: Himedo Park, Kugushima, Wadanohana, Higashiura, and Kotorigoe. A detailed geological survey and taxonomic analysis was undertaken, and the habitat, depositional environment, and associated mollusks of each locality were considered in the context of previous studies. Twenty-one species, 15 genera, 11 families, and 6 orders of fossil sharks are recognized from the localities. This assemblage is more diverse than has previously been reported for Japan, and Lamniformes and Hexanchiformes were abundant. Three categories of shark fauna are recognized: a coastal region (Himedo Park; probably a breeding site), the coast to the open sea (Kugushima and Wadanohana), and bottom-dwelling or near-seafloor fauna (Kugushima, Wadanohana, Higashiura, and Kotorigoe). -
Whale Shark Rhincodon Typus Populations Along the West Coast of the Gulf of California and Implications for Management
Vol. 18: 115–128, 2012 ENDANGERED SPECIES RESEARCH Published online August 16 doi: 10.3354/esr00437 Endang Species Res Whale shark Rhincodon typus populations along the west coast of the Gulf of California and implications for management Dení Ramírez-Macías1,2,*, Abraham Vázquez-Haikin3, Ricardo Vázquez-Juárez1 1Centro de Investigaciones Biológicas del Noroeste, Mar Bermejo 195, Col. Playa Palo de Santa Rita, La Paz, Baja California Sur 23096, Mexico 2Tiburón Ballena México de Conciencia México, Manatí 4802, Col. Esperanza III, La Paz, Baja California Sur 23090, Mexico 3Asociación de Pesca Deportiva y Ecoturismo de Bahía de los Ángeles, Domicilio conocido Bahía de los Ángeles, Baja California 22980, Mexico ABSTRACT: We used photo-identification data collected from 2003 through 2009 to estimate pop- ulation structure, site fidelity, abundance, and movements of this species along the west coast of the Gulf of California to make recommendations for effective conservation and management. Of 251 whale sharks identified from 1784 photographs, 129 sharks were identified in Bahía de Los Ángeles and 125 in Bahía de La Paz. Only juveniles (mostly small) were found in these 2 bays. At Isla Espíritu Santo, we identified adult females; at Gorda Banks we identified 15 pregnant females. High re-sighting rates within and across years provided evidence of site fidelity among juvenile sharks in the 2 bays. Though the juveniles were not permanent residents, they used the areas regularly from year to year. A proportion of the juveniles spent days to a month or more in the coastal waters of the 2 bays before leaving, and periods of over a month outside the study areas before entering the bays again. -
An Introduction to the Classification of Elasmobranchs
An introduction to the classification of elasmobranchs 17 Rekha J. Nair and P.U Zacharia Central Marine Fisheries Research Institute, Kochi-682 018 Introduction eyed, stomachless, deep-sea creatures that possess an upper jaw which is fused to its cranium (unlike in sharks). The term Elasmobranchs or chondrichthyans refers to the The great majority of the commercially important species of group of marine organisms with a skeleton made of cartilage. chondrichthyans are elasmobranchs. The latter are named They include sharks, skates, rays and chimaeras. These for their plated gills which communicate to the exterior by organisms are characterised by and differ from their sister 5–7 openings. In total, there are about 869+ extant species group of bony fishes in the characteristics like cartilaginous of elasmobranchs, with about 400+ of those being sharks skeleton, absence of swim bladders and presence of five and the rest skates and rays. Taxonomy is also perhaps to seven pairs of naked gill slits that are not covered by an infamously known for its constant, yet essential, revisions operculum. The chondrichthyans which are placed in Class of the relationships and identity of different organisms. Elasmobranchii are grouped into two main subdivisions Classification of elasmobranchs certainly does not evade this Holocephalii (Chimaeras or ratfishes and elephant fishes) process, and species are sometimes lumped in with other with three families and approximately 37 species inhabiting species, or renamed, or assigned to different families and deep cool waters; and the Elasmobranchii, which is a large, other taxonomic groupings. It is certain, however, that such diverse group (sharks, skates and rays) with representatives revisions will clarify our view of the taxonomy and phylogeny in all types of environments, from fresh waters to the bottom (evolutionary relationships) of elasmobranchs, leading to a of marine trenches and from polar regions to warm tropical better understanding of how these creatures evolved. -
Research and Conservation at Georgia Aquarium, Inc
RESEARCH AND CONSERVATION AT GEORGIA AQUARIUM, INC. Georgia Aquarium is committed to the research and conservation of aquatic animals around the world. As a leader in marine research, Georgia Aquarium contributes to the advancement of knowledge of our blue planet by studying animals here at the Aquarium and in their natural environments. Since opening, members of the Aquarium’s research team have participated in nearly 100 funded research projects and authored more than 130 peer-reviewed publications and conference appearances. Our researchers collaborate with scientists around the world to understand our aquatic world so that we may conserve it for generations to come. Conservation Field Station The Georgia Aquarium Conservation Field Station (GACFS) in Marineland, Fla., is dedicated to the research and rescue of dolphins and whales in northeast Florida. The GACFS team responds to marine mammal strandings and distress calls, and researchers contribute to a recurring photo identification survey that documents the resident bottlenose dolphin population in northern Florida. The GACFS is also committed to community outreach, with school outreach courses, camps and stranding awareness programs to educate the public. ONGOING AND MILESTONE RESEARCH & CONSERVATION EFFORTS Whale Sharks Georgia Aquarium is a worldwide leader in whale shark research and conservation. We’ve sent teams to learn more about these gentle giants off the coast of Mexico, Taiwan, the Galapagos Islands and Saint Helena, an island in the middle of the South Atlantic Ocean. In 2009, our joint studies with the Project Domino consortium led to the Mexican government’s creation of the Whale Shark Biosphere Reserve, a protected area for this vulnerable species in Yucatan, Mexico. -
Phylogenetic Analysis of the Allometry of Metabolic Rate and Mitochondrial Basal Proton Leak
Author’s Accepted Manuscript Phylogenetic analysis of the allometry of metabolic rate and mitochondrial basal proton leak Elias T. Polymeropoulos, R. Oelkrug, C.R. White, M. Jastroch www.elsevier.com/locate/jtherbio PII: S0306-4565(16)30294-7 DOI: http://dx.doi.org/10.1016/j.jtherbio.2017.01.013 Reference: TB1878 To appear in: Journal of Thermal Biology Received date: 28 September 2016 Revised date: 24 January 2017 Accepted date: 25 January 2017 Cite this article as: Elias T. Polymeropoulos, R. Oelkrug, C.R. White and M. Jastroch, Phylogenetic analysis of the allometry of metabolic rate and mitochondrial basal proton leak, Journal of Thermal Biology, http://dx.doi.org/10.1016/j.jtherbio.2017.01.013 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Phylogenetic analysis of the allometry of metabolic rate and mitochondrial basal proton leak 1 2 3 4,5 Polymeropoulos Elias T. , Oelkrug R. , White C.R. , Jastroch M. 1Menzies Institute for Medical Research, University of Tasmania, 7001 Hobart, Australia, 2Center of Brain, Behaviour and Metabolism, University of Lübeck, 23562 Lübeck, Germany, 3Centre for Geometric Biology, School of Biological Sciences, Monash University, 3800 Melbourne, Australia 4Institute for Diabetes and Obesity, Helmholtz Zentrum, 85764 Munich, Germany, 5 Department of Animal Physiology, Faculty of Biology, Philipps University of Marburg, D-35032 Marburg, Germany Abstract The mitochondrial basal proton leak (MBPL) significantly contributes to high body temperatures (Tb) and basal metabolic rates (BMR) in endotherms. -
On Giant Filter Feeders 170 Million Years
PERSPECTIVES PALEONTOLOGY Massive fi lter-feeding vertebrates have roamed the world’s oceans for the past On Giant Filter Feeders 170 million years. Lionel Cavin he largest living marine verte- years ago), the diversity of mysticete whales these fi shes engulfed water by swimming brates—baleen whales and several was linked to the diversity of diatoms and to with an open mouth and sieved food while T lineages of sharks and rays—feed climatic variations (4 ). water escaped through the gill arches. directly on very small organisms (such as In the Jurassic (200 to 145 million years Giant reptiles roamed the Jurassic and plankton and small fi shes). Planktivorous ago) and the Cretaceous (145 to 65 million Cretaceous oceans, and some huge ray- sharks and rays collect food by fi ltering sea- years ago), ray-fi nned fi shes called pachy- fi nned fi shes—the ichthyodectiforms (bull- water through gill rakers (fi ngerlike pro- cormiforms lived in the oceans. These extinct dog fi sh and relatives)—emerged at the end jections on gill arches), whereas mysticete fishes are regarded as primitive teleosts, of the Cretaceous. But all these beasts were whales sieve small animals from seawater the group to which most living bony fi shes apex predators that fed on large preys, and through whalebone or baleen (comblike belong (5 ). A giant representative from the none had a fi lter-feeding diet. The newly keratin structures in their upper jaws) (1 , Middle Jurassic, Leedsichthys, was up to 9 discovered clade of massive fi lter-feeding 2). On page 990 of this issue, Friedman et m long and has been interpreted as a fi lter fi shes thus fi lls a large ecological niche. -
First Description of a Tooth of the Extinct Giant Shark Carcharocles
First description of a tooth of the extinct giant shark Carcharocles megalodon (Agassiz, 1835) found in the province of Seville (SW Iberian Peninsula) (Otodontidae) Primera descripción de un diente del extinto tiburón gigante Carcharocles megalodon (Agassiz, 1835) encontrado en la provincia de Sevilla (SO de la Península Ibérica) (Otodontidae) José Luis Medina-Gavilán 1, Antonio Toscano 2, Fernando Muñiz 3, Francisco Javier Delgado 4 1. Sociedad de Estudios Ambientales (SOCEAMB) − Perú 4, 41100 Coria del Río, Sevilla (Spain) − [email protected] 2. Departamento de Geodinámica y Paleontología, Facultad de Ciencias Experimentales, Universidad de Huelva − Campus El Carmen, 21071 Huelva (Spain) − [email protected] 3. Departamento de Geodinámica y Paleontología, Facultad de Ciencias Experimentales, Universidad de Huelva − Campus El Carmen, 21071 Huelva (Spain) − [email protected] 4. Usuario de BiodiversidadVirtual.org − Álvarez Quintero 13, 41220 Burguillos, Sevilla (Spain) − [email protected] ABSTRACT: Fossil remains of the extinct giant shark Carcharocles megalodon (Agassiz, 1835) are rare in interior Andalusia (Southern Spain). For the first time, a fossil tooth belonging to this paleospecies is described from material found in the province of Seville (Burguillos). KEY WORDS: Carcharocles megalodon (Agassiz, 1835), megalodon, Otodontidae, fossil, paleontology, Burguillos, Seville, Tortonian. RESUMEN: Los restos del extinto tiburón gigante Carcharocles megalodon (Agassiz, 1835) son raros en el interior de Andalucía (sur de España). Por primera vez, se describe un diente fósil de esta paleoespecie a partir de material hallado en Sevilla (Burguillos). PALABRAS CLAVE: Carcharocles megalodon (Agassiz, 1835), megalodón, Otodontidae, fósil, paleontología, Burguillos, Sevilla, Tortoniense. Introduction Carcharocles megalodon (Agassiz, 1835), the megalodon, is widely recognised as the largest shark that ever lived. -
A Review of Planktivorous Fishes: Their Evolution, Feeding Behaviours, Selectivities, and Impacts
Hydrobiologia 146: 97-167 (1987) 97 0 Dr W. Junk Publishers, Dordrecht - Printed in the Netherlands A review of planktivorous fishes: Their evolution, feeding behaviours, selectivities, and impacts I Xavier Lazzaro ORSTOM (Institut Français de Recherche Scientifique pour le Développement eri Coopération), 213, rue Lu Fayette, 75480 Paris Cedex IO, France Present address: Laboratorio de Limrzologia, Centro de Recursos Hidricob e Ecologia Aplicada, Departamento de Hidraulica e Sarzeamento, Universidade de São Paulo, AV,DI: Carlos Botelho, 1465, São Carlos, Sï? 13560, Brazil t’ Mail address: CI? 337, São Carlos, SI? 13560, Brazil Keywords: planktivorous fish, feeding behaviours, feeding selectivities, electivity indices, fish-plankton interactions, predator-prey models Mots clés: poissons planctophages, comportements alimentaires, sélectivités alimentaires, indices d’électivité, interactions poissons-pltpcton, modèles prédateurs-proies I Résumé La vision classique des limnologistes fut de considérer les interactions cntre les composants des écosystè- mes lacustres comme un flux d’influence unidirectionnel des sels nutritifs vers le phytoplancton, le zoo- plancton, et finalement les poissons, par l’intermédiaire de processus de contrôle successivement physiqucs, chimiques, puis biologiques (StraSkraba, 1967). L‘effet exercé par les poissons plaiictophages sur les commu- nautés zoo- et phytoplanctoniques ne fut reconnu qu’à partir des travaux de HrbáEek et al. (1961), HrbAEek (1962), Brooks & Dodson (1965), et StraSkraba (1965). Ces auteurs montrèrent (1) que dans les étangs et lacs en présence de poissons planctophages prédateurs visuels. les conimuiiautés‘zooplanctoniques étaient com- posées d’espèces de plus petites tailles que celles présentes dans les milieux dépourvus de planctophages et, (2) que les communautés zooplanctoniques résultantes, composées d’espèces de petites tailles, influençaient les communautés phytoplanctoniques. -
(Chondrichthyes, Elasmobranchii) from the Upper Cretaceous of South America
A ptychodontid (Chondrichthyes, Elasmobranchii) from the Upper Cretaceous of South America Paulo M. BRITO Departamento de Biologia Animal e Vegetal, Universidade do Estado do Rio de Janeiro, rua São Francisco Xavier, 524, Rio de Janeiro (Brazil) [email protected] Philippe JANVIER UMR 8569 du CNRS, Département Histoire de la Terre, Muséum national d’Histoire naturelle, 8 rue Buffon, F-75231 Paris cedex 05 (France) [email protected] Brito P. M. & Janvier P. 2002. — A ptychodontid (Chondrichthyes, Elasmobranchii) from the Upper Cretaceous of South America. Geodiversitas 24 (4) : 785-790. ABSTRACT An articulated assemblage of chondrichthyan teeth remain, previously described by Larrazet (1886) as selachian dermal scutes from the Carboniferous of New Granada, is re-described as a Ptychodus sp. and turns out to be Cretaceous in age, presumably from the La Luna Formation of Colombia or Venezuela. This Ptychodus species seems to differ from all the other known ptychodon- KEY WORDS tids by its homodontous dentition, tooth morphology and ornamentation, Chondrichthyes, however we prefer not to erect a new taxon here until tooth morphology Ptychodontidae, Upper Cretaceous, morphoclines become better known and help in the understanding of the South America. phylogenetic relationships among chondrichthyans. RÉSUMÉ Un ptychodontidé (Chondrichthyes, Elasmobranchii) du Crétacé supérieur d’Amérique du Sud. Une plaque dentaire de Chondrichthyes, précédemment décrite par Larrazet (1886) comme des plaques dermiques d’un Sélacien du Carbonifère de la Nouvelle -
Upper Cretaceous Chondrichthyes Teeth Record in Phosphorites of the Loma Gorda Formation•
BOLETIN DE CIENCIAS DE LA TIERRA http://www.revistas.unal.edu.co/index.php/rbct Upper Cretaceous chondrichthyes teeth record in phosphorites of the • Loma Gorda formation Alejandro Niño-Garcia, Juan Diego Parra-Mosquera & Peter Anthony Macias-Villarraga Departamento de Geociencias, Facultad de Ciencias Naturales y Exactas, Universidad de Caldas, Manizales, Colombia. [email protected], [email protected], [email protected] Received: April 26th, 2019. Received in revised form: May 17th, 2019. Accepted: June 04th, 2019. Abstract In layers of phosphorites and gray calcareous mudstones of the Loma Gorda Formation, in the vicinity of the municipal seat of Yaguará in Huila department, Colombia, were found fossils teeth of chondrichthyes, these were extracted from the rocks by mechanical means, to be compared with the species in the bibliography in order to indentify them. The species were: Ptychodus mortoni (order Hybodontiformes), were found, Squalicorax falcatus and Cretodus crassidens (order Lamniformes). This finding constitutes the first record of these species in the Colombian territory; which allows to extend its paleogeographic distribution to the northern region of South America, which until now was limited to Africa, Europe, Asia and North America, except for the Ptychodus mortoni that has been described before in Venezuela. Keywords: first record; sharks; upper Cretaceous; fossil teeth; Colombia. Registro de dientes de condrictios del Cretácico Superior en fosforitas de la formación Loma Gorda Resumen En capas de fosforitas y lodolitas calcáreas grises de la Formación Loma Gorda, en cercanías de la cabecera municipal de Yaguará en el departamento del Huila, Colombia, se encontraron dientes fósiles de condrictios; estos fueron extraídos de la roca por medios mecánicos, para ser comparados con las especies encontradas en la bibliografía e identificarlos. -
Dinosaur Metabolism and the Allometry of Maximum Growth Rate
RESEARCH ARTICLE Dinosaur Metabolism and the Allometry of Maximum Growth Rate Nathan P. Myhrvold* Intellectual Ventures, Bellevue, Washington, United States of America * [email protected] Abstract a11111 The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical OPEN ACCESS power of the regressions. The maximum growth rates of extant groups are found to have a Citation: Myhrvold NP (2016) Dinosaur great deal of overlap, including between groups with endothermic and ectothermic metabo- Metabolism and the Allometry of Maximum lism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, Growth Rate. PLoS ONE 11(11): e0163205. reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature doi:10.1371/journal.pone.0163205 (on a log-log scale) for many groups, contradicting the prevailing view that growth rate Editor: Anthony Fiorillo, Perot Museum of Nature allometry follows a simple power law. Reanalysis shows that no correlation between growth and Science, UNITED STATES rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a con- Received: January 7, 2015 clusion that growth rate allometry studies to date cannot be used to determine dinosaur Accepted: September 6, 2016 metabolism as has been previously argued.