DOCSLIB.ORG

A Record of Clidastes Propython Cope (Squamata, Mosasauridae) in the Upper Cretaceous of the Saratov Region, Russia D

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Record of Clidastes Propython Cope (Squamata, Mosasauridae) in the Upper Cretaceous of the Saratov Region, Russia D ISSN 00310301, Paleontological Journal, 2015, Vol. 49, No. 5, pp. 512–520. © Pleiades Publishing, Ltd., 2015. Original Russian Text © D.V. Grigoriev, M.S. Arkhangelsky, S.M. Merkulov, 2015, published in Paleontologicheskii Zhurnal, 2015, No. 5, pp. 60–68. A Record of Clidastes propython Cope (Squamata, Mosasauridae) in the Upper Cretaceous of the Saratov Region, Russia D. V. Grigorieva, M. S. Arkhangelskyb, c, and S. M. Merkulovd aZoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg, 199034 Russia bSaratov State Technical University, Saratov, 410016 Russia cSaratov State University, Universitetskaya ul. 42, Saratov, 410601 Russia dGroup “Iskateli,” Moskovskaya ul. 88, Saratov, 410012 Russia email: [email protected] Received June 05, 2014 Abstract—A frontal of the mosasaur Clidastes propython from the Beloe Ozero locality in the Saratov Region (Rybushka Formation, Campanian Stage, Upper Cretaceous) is described. The investigated specimen differs from the frontals of other members of the genus Clidastes in the relatively straight lateral flanks. Reliable records of Clidastes outside America have previously been reported only from Great Britain, Sweden, and Germany. The new record from the Beloe Ozero locality expands the known geographical range of the species C. propython and genus Clidastes. Keywords: Clidastes, Upper Cretaceous, Saratov Region, Russia DOI: 10.1134/S003103011505007X INTRODUCTION of the Russian Academy of Sciences, St. Petersburg (ZIN PH). Mosasaur remains in the Upper Cretaceous beds of For comparison were used specimens from the Yale Russia and adjacent areas are rather common; how Peabody Museum of Natural History, New Haven, ever, morphologically complete skeletons are Connecticut, United States (YPM), and Geological extremely scarce. They include a skeleton of Progna Survey of Alabama Type Collection, Tuscaloosa, Ala thodon lutugini from the Campanian of eastern bama, United States (GSATC). The systematics in Ukraine (Yakovlev, 1905; Grigoriev, 2013) and also an this study follows Palci et al. (2013). incomplete skull of Mosasaurus hoffmanni from the Upper Maastrichtian beds of Penza (Grigoriev, 2014). The majority of known specimens are represented by GEOLOGICAL AND TAPHONOMIC isolated bones of the skull and postcranial skeleton. CHARACTERISTICS OF THE LOCALITY Among cranial elements, the frontal, along with The Beloe Ozero locality is situated 2.6 km southeast the quadrate and teeth, displays the greatest number of of the village of Beloe Ozero (Lysogorskii District, diagnostic characters. The frontal described in this Saratov Region) and represents a natural outcrop of the work was found in 2013 in the Campanian beds of the Campanian beds (Rybushka Formation) in the right Beloe Ozero locality of the Lysogorskii District on the slope of an unnamed gully in its middle part (Fig. 1). Saratov Region. In this territory the Campanian Stage The Rybushka Formation has yielded fossils of is correlated with the Rybushka Formation of the local invertebrates: the belemnites Belemnellocamax mam stratigraphical scale. This locality has yielded many millatus and Belemnitella mucronata, the ammonite specimens of mosasaurs, plesiosaurs, pterosaurs, and Hoplitoplacenticeras sp., the bivalves Oxytoma psilo others vertebrates (Pervushov et al., 1999; Arkhangel monica, O. tenuicostata, Cataceramus balticus, C. regu sky et al., 2007; Averianov and Popov, 2014). laris, and foraminifers of the Brotzenella monterelensis On the dorsal and ventral sides, the bone was covered Regional Zone and Cibicidoides aktulagayensis Sub with a layer of dense sandstone hiding many diagnostic zone (Olferiev and Alekseev, 2005; Seltser and Ivanov, characters. Enclosing matter was removed using a den 2010; Averianov and Popov, 2014). The formation cor tal drilling machine and air compressor (JUNAIR i40 responds in stratigraphical volume to most of the 4B) with an air scribe (Paleo Tools ME9100). Lower Campanian (Belemnitella mucronata alpha and Belemnellocamax mammillatus regional mollusk lones) The specimen investigated is housed in the Paleo and basal Upper Campanian (Hoplitoplacenticeras herpetological Collection of the Zoological Institute coesfeldiense/Belemnitella mucronata mucronata lone) 512 A RECORD OF CLIDASTES PROPYTHON COPE (SQUAMATA, MOSASAURIDAE) 513 Lysye Penza Gory Tambov Region Region E38 Saratov r ive Region R a er olg iv V R a ts di ve Saratov ed M Voro Karamysh R Shirokii iver nezh Karamysh Region N Beloe 5 km Ozero Volgograd Kazakhstan Region Fig. 1. Geographical position of the Beloe Ozero locality. (Olferiev and Alekseev, 2005). Among vertebrate Deposits of the Rybushka Formation are represented remains from the Rybushka Formation, bones of oste here by (downward in the section) (Fig. 2): ichthyans (Enchodontidae), shark teeth (Cretolamna К2 km2 1. Greenish gray, quartz–glauconitic, appendiculata, Squalicorax kaupi, Pseudocorax laevis, mediumgrained sand, in the upper part, the bed is Archaeolamna kopingensis, Eostriatolamia sp., Hetero strongly stained with chernozem; in the lower part, it dontus sp., Squatina hasei, Squatirhina sp.), dental is in places strongly compacted, sometimes to the con plates of the chimaeras Ischyodus bifurcatus, Amylodon dition of sandstone. Over the entire bed, dark brown karamysh, Edaphodon sp., Elasmodus sp. prevail phosphorite inclusions up to 2.5 cm in size and ferrif (Averianov and Popov, 2014). This formation has also erous inclusions up to 3 cm in size are regularly scat yielded abundant fossils of reptiles (plesiosaurs, mosa tered. The boundary with the underlying bed is dis saurids, sea turtles, pterosaurs) and birds (Hesperor tinct, but uneven. The bed is up to 3.0 m thick. nises). Beds 1 and 2 are tentatively dated Upper Cam К2 km12 2. Phosphorite horizon. Brown and dark panian; Beds 3–6 are regarded as Lower Campanian. brown, poorly sabulous, irregularly shaped phospho The Rybushka Formation is situated between a rite nodules up to 3.5 cm in size. Small phosphorites longlived Voronezh island system and more deepwa (less than 1 cm) are usual. Along the strike, phospho ter sites of the Recent left bank of the Saratov Region, rite inclusions are distributed nonuniformly, forming which are connected with the Caspian Depression. in places lenticular aggregations or, on the contrary, This territory was completely occupied by a shallow wedging out. In some sites, the horizon is nonuni marine basin. All localities of marine and subconti formly stained with brownish red spots of iron hydrox nental vertebrates occur in the zones of Campanian ide. There are also rare gray aleurite–carbonate pel coastal bands and island banks. They were formed due lets. The horizon is in places slightly cemented. to consedimentary development of uplifted structures. Cementing matter is psammitic component of the Depending on the influence of water masses of differ overlying layer. The lower surface is uneven and pitted. ent climatic zones and a complex relief of the sea bot The bed has yielded abundant shark teeth and verte tom, this area accumulated siliciclastic matter and sil brae, fin spines and dental plates of chimaeras, iceous–clayey deposits (Pervushov et al., 2012). remains of large sturgeons and clupeids, bones and teeth of reptiles (mosasaurs, plesiosaurs, turtles, pte A significant part of the section of the Beloe Ozero rosaurs); shark coprolites up to 8 cm long are particu locality was buried under a thick, turfcovered talus. larly abundant. The bed is up to 0.2 m thick. PALEONTOLOGICAL JOURNAL Vol. 49 No. 5 2015 514 GRIGORIEV et al. Lithology Stage Bed no. Substage Formation Thickness, m 1 2 1 3 Upper 3 ? 2 0.2 4 3 5 5 6 Lower Campanian Rybushka 4 0.5 a 7 b 8 5 3 9 10 6 3 11 Fig. 2. Geological section of the Upper Cretaceous beds of the Beloe Ozero locality. Designations: (1) sandstone, (2) sand, (3) glauconite, (4) phosphatic and silty–carbonate pellets, (5) ferrugination, (6) tetrapod bones, (7) chondrichthian teeth: (a) rays and (b) sharks, (8) remains of bony fishes, (9) burrows of mudeaters, (10) coprolites of sharks, (11) presumable level of find of the frontal (specimen ZIN PH, no. 5/48). The underlying beds are covered by a talus, in K2 km1 4. Light gray, glauconitic–quartz, medium– places, with landslide deposits. The beds are described finegrained, platy, sandstone gradually passing into the based on a series of trenches and grubbing. underlying bed. There are many subhorizontally posi tioned burrows of mudeaters, stained with iron К2 km1 3. Gray–green, quartz–glauconitic, hydroxide. The lower surface of the bed is uneven. The mediumgrained sand. In the upper part, the bed con bed is up to 0.3–0.5 m thick. tains subautochthonous, slightly phosphatized copro lites of sharks and small vertebrae of bony fish. The К2 km1 5. Gray–green, quartz–glauconitic, boundary with the underlying bed is uneven. The bed medium–finegrained sand. The bed is about 3.0 m is 4–5 m thick. thick. PALEONTOLOGICAL JOURNAL Vol. 49 No. 5 2015 A RECORD OF CLIDASTES PROPYTHON COPE (SQUAMATA, MOSASAURIDAE) 515 К2 km1 6. Gray–greenish, quartz–glauconitic, to that of the prefrontal. The anterior and posterior cement siliceous sandstone; cementation is nonuni boundaries of these sutural surfaces are represented by form. Glauconitic grains are mostly black, form large notches (more pronounced posteriorly). The ventral clumpy structures about 0.5 × 1.0 m in size. The cracks separation ridge between the prefrontal and postorb are stained brown with iron hydroxide. The bed sole itofrontal is 17 mm wide. encloses abundant subhorizontal burrows of crusta The boundary with the parietal is very well pro ceans 1.5–2 cm in diameter and up to 30 cm long, nounced. It is represented by two plates located at the filled with the rock of the bed. The level of hard ground middle of the posterior bone margin and also sutural unpersistent along the strike is outlined at the bed sole. surface between the plates and on their sides. The The bed contains slightly phosphatized vertebrae of a plates originate from the bone edge on the dorsal side large shark and plesiosaur and also rare coprolites of and converge close to the center on the ventral side.
Load more

Recommended publications
  • JVP 26(3) September 2006—ABSTRACTS
    Neoceti Symposium, Saturday 8:45 acid-prepared osteolepiforms Medoevia and Gogonasus has offered strong support for BODY SIZE AND CRYPTIC TROPHIC SEPARATION OF GENERALIZED Jarvik’s interpretation, but Eusthenopteron itself has not been reexamined in detail. PIERCE-FEEDING CETACEANS: THE ROLE OF FEEDING DIVERSITY DUR- Uncertainty has persisted about the relationship between the large endoskeletal “fenestra ING THE RISE OF THE NEOCETI endochoanalis” and the apparently much smaller choana, and about the occlusion of upper ADAM, Peter, Univ. of California, Los Angeles, Los Angeles, CA; JETT, Kristin, Univ. of and lower jaw fangs relative to the choana. California, Davis, Davis, CA; OLSON, Joshua, Univ. of California, Los Angeles, Los A CT scan investigation of a large skull of Eusthenopteron, carried out in collaboration Angeles, CA with University of Texas and Parc de Miguasha, offers an opportunity to image and digital- Marine mammals with homodont dentition and relatively little specialization of the feeding ly “dissect” a complete three-dimensional snout region. We find that a choana is indeed apparatus are often categorized as generalist eaters of squid and fish. However, analyses of present, somewhat narrower but otherwise similar to that described by Jarvik. It does not many modern ecosystems reveal the importance of body size in determining trophic parti- receive the anterior coronoid fang, which bites mesial to the edge of the dermopalatine and tioning and diversity among predators. We established relationships between body sizes of is received by a pit in that bone. The fenestra endochoanalis is partly floored by the vomer extant cetaceans and their prey in order to infer prey size and potential trophic separation of and the dermopalatine, restricting the choana to the lateral part of the fenestra.
    [Show full text]
  • Tylosaurine Mosasaurs (Squamata) from the Late Cretaceous of Northern Germany
    Netherlands Journal of Geosciences —– Geologie en Mijnbouw | 94 – 1 | 55-71 | 2015 doi: 10.1017/njg.2014.31 Tylosaurine mosasaurs (Squamata) from the Late Cretaceous of northern Germany J.J. Hornung1,2,* &M.Reich3,4 1 Georg-August University Gottingen,¨ Geoscience Centre, Department of Geobiology, Goldschmidt-Straße 3, 37077 Gottingen,¨ Germany 2 Current address: Fuhlsbuttler¨ Str. 611, 22337 Hamburg, Germany 3 SNSB - Bavarian State Collection for Palaeontology and Geology, Richard-Wagner-Str. 10, 80333 Munich, Germany 4 Department of Earth and Environmental Sciences, Ludwig-Maximilians University Munchen,¨ Richard-Wagner-Str. 10, 80333 Munich, Germany * Corresponding author. Email: [email protected] Manuscript received: 27 April 2014, accepted: 18 September 2014 Abstract Two genera of tylosaurine mosasaurs, Tylosaurus and Hainosaurus, are recorded for the first time from Germany. Tylosaurus sp. is represented by two isolated tooth crowns, originally described as Mosasaurus? alseni (here considered a nomen dubium) from the latest Santonian–Early Campanian, which are very similar to T. ivoensis and T. gaudryi.ThematerialofHainosaurus sp. comprises a maxillary with associated postorbitofrontal, two pterygoid teeth and several indeterminate cranial fragments. The specimen from the Late Campanian is slightly less derived than H. bernardi from the Maastrichtian in retaining labiolingually less compressed anterior maxillary teeth and unserrated pterygoid teeth with only very weak carinae. Despite only minor skeletal differences, the genus Hainosaurus is considered to be distinct from Tylosaurus because of its significant modification of the dental apparatus compared to the plesiomorphic condition in the latter. This dental morphology suggests a phylogenetic trend from a generalised-piercing marginal dentition in Tylosaurus towards the increasingly labiolingually compressed, symmetrical, strongly bicarinate cutting marginal teeth in Hainosaurus spp.
    [Show full text]
  • Estimating the Evolutionary Rates in Mosasauroids and Plesiosaurs: Discussion of Niche Occupation in Late Cretaceous Seas
    Estimating the evolutionary rates in mosasauroids and plesiosaurs: discussion of niche occupation in Late Cretaceous seas Daniel Madzia1 and Andrea Cau2 1 Department of Evolutionary Paleobiology, Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland 2 Independent, Parma, Italy ABSTRACT Observations of temporal overlap of niche occupation among Late Cretaceous marine amniotes suggest that the rise and diversification of mosasauroid squamates might have been influenced by competition with or disappearance of some plesiosaur taxa. We discuss that hypothesis through comparisons of the rates of morphological evolution of mosasauroids throughout their evolutionary history with those inferred for contemporary plesiosaur clades. We used expanded versions of two species- level phylogenetic datasets of both these groups, updated them with stratigraphic information, and analyzed using the Bayesian inference to estimate the rates of divergence for each clade. The oscillations in evolutionary rates of the mosasauroid and plesiosaur lineages that overlapped in time and space were then used as a baseline for discussion and comparisons of traits that can affect the shape of the niche structures of aquatic amniotes, such as tooth morphologies, body size, swimming abilities, metabolism, and reproduction. Only two groups of plesiosaurs are considered to be possible niche competitors of mosasauroids: the brachauchenine pliosaurids and the polycotylid leptocleidians. However, direct evidence for interactions between mosasauroids and plesiosaurs is scarce and limited only to large mosasauroids as the Submitted 31 July 2019 predators/scavengers and polycotylids as their prey. The first mosasauroids differed Accepted 18 March 2020 from contemporary plesiosaurs in certain aspects of all discussed traits and no evidence Published 13 April 2020 suggests that early representatives of Mosasauroidea diversified after competitions with Corresponding author plesiosaurs.
    [Show full text]
  • (Squamata: Mosasauridae) from the Late Cretaceous Of
    C. R. Palevol 14 (2015) 483–493 Contents lists available at ScienceDirect Comptes Rendus Palevol www.sci encedirect.com General Palaeontology, Systematics and Evolution (Vertebrate Palaeontology) An halisaurine (Squamata: Mosasauridae) from the Late Cretaceous of Patagonia, with a preserved tympanic disc: Insights into the mosasaur middle ear Un halisauriné (Squamata : Mosasauridae) du Crétacé supérieur de Patagonie, à disque tympanique conservé : un aperc¸ u de l’oreille moyenne des mosasaures a,∗ b Marta S. Fernández , Marianella Talevi a CONICET - División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque s/n, 1900 La Plata, Argentina b CONICET - Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, Isidro Lobo y Belgrano, 8332 General Roca, Río Negro, Argentina a b s t r a c t a r t i c l e i n f o Article history: Halisaurinae is a subfamily of enigmatic, small- to medium-sized mosasauroids, which Received 15 September 2014 retain a mosaic of primitive and derived features. The first record of a South American Hal- Accepted after revision 13 May 2015 isaurus with precise stratigraphic information includes a quadrate carrying a tympanic disc together with twelve vertebrae, collected in the Late Maastrichtian of Jagüel Formation Handled by Nathalie Bardet in northern Patagonia (Argentina). The preservation of a tympanic disc allows exploring and discussing the mechanisms of sound transmission in these mosasauroids. The loca- Keywords: tion of the tympanic disc resembles that one formed by the extracolumella of aquatic Halisaurus turtles and at least one extant lizard. Based on morphological comparison of the middle Patagonia ear we discuss previous hypotheses on the modification of the tympanic middle ear system Late Maastrichtian of mosasauroids for underwater hearing, in a manner similar to that observed in aquatic Cretaceous turtles.
    [Show full text]
  • Download Full Article in PDF Format
    comptes rendus palevol 2021 20 20 iles — Jean- pt Cl re au d d n e a R s a n g a e i — b i h P p a l a m e a o f b o i o y l h o p g a y r g a o n e d g p o i a l b a o e DIRECTEURS DE LA PUBLICATION / PUBLICATION DIRECTORS : Bruno David, Président du Muséum national d’Histoire naturelle Étienne Ghys, Secrétaire perpétuel de l’Académie des sciences RÉDACTEURS EN CHEF / EDITORS-IN-CHIEF : Michel Laurin (CNRS), Philippe Taquet (Académie des sciences) ASSISTANTE DE RÉDACTION / ASSISTANT EDITOR : Adenise Lopes (Académie des sciences ; [email protected]) MISE EN PAGE / PAGE LAYOUT : Fariza Sissi (Muséum national d’Histoire naturelle ; [email protected]) RÉVISIONS LINGUISTIQUES DES TEXTES ANGLAIS / ENGLISH LANGUAGE REVISIONS : Kevin Padian (University of California at Berkeley) RÉDACTEURS ASSOCIÉS / ASSOCIATE EDITORS : Micropaléontologie/Micropalaeontology Maria Rose Petrizzo (Università di Milano, Milano) Paléobotanique/Palaeobotany Cyrille Prestianni (Royal Belgian Institute of Natural Sciences, Brussels) Métazoaires/Metazoa Annalisa Ferretti (Università di Modena e Reggio Emilia, Modena) Paléoichthyologie/Palaeoichthyology Philippe Janvier (Muséum national d’Histoire naturelle, Académie des sciences, Paris) Amniotes du Mésozoïque/Mesozoic amniotes Hans-Dieter Sues (Smithsonian National Museum of Natural History, Washington) Tortues/Turtles Juliana Sterli (CONICET, Museo Paleontológico Egidio Feruglio, Trelew) Lépidosauromorphes/Lepidosauromorphs Hussam Zaher (Universidade de São Paulo) Oiseaux/Birds Eric Buffetaut (CNRS, École Normale Supérieure, Paris) Paléomammalogie (mammifères de moyenne et grande taille)/Palaeomammalogy (large and mid-sized mammals) Lorenzo Rook* (Università degli Studi di Firenze, Firenze) Paléomammalogie (petits mammifères sauf Euarchontoglires)/Palaeomammalogy (small mammals except for Euarchontoglires) Robert Asher (Cambridge University, Cambridge) Paléomammalogie (Euarchontoglires)/Palaeomammalogy (Euarchontoglires) K.
    [Show full text]
  • Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations in the Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae)
    Fort Hays State University FHSU Scholars Repository Sternberg Museum of Natural History Faculty Publications Sternberg Museum of Natural History 12-1-2011 Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations in the Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae) Johan Lindgren Lunds Universitet Michael J. Everhart Fort Hays State University Michael W. Caldwell University of Alberta Follow this and additional works at: https://scholars.fhsu.edu/sternberg_facpubs Part of the Paleontology Commons Recommended Citation Lindgren, J., Everhart, M. J., & Caldwell, M. W. (2011). Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations in the Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae). PLOS ONE, 6(11), e27343. https://doi.org/10.1371/journal.pone.0027343 This Article is brought to you for free and open access by the Sternberg Museum of Natural History at FHSU Scholars Repository. It has been accepted for inclusion in Sternberg Museum of Natural History Faculty Publications by an authorized administrator of FHSU Scholars Repository. Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations in the Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae) Johan Lindgren1*, Michael J. Everhart2, Michael W. Caldwell3 1 Department of Earth and Ecosystem Sciences, Lund University, Lund, Sweden, 2 Sternberg Museum of Natural History, Fort Hays State University, Hays, Kansas, United States of America, 3 Department of Earth and Atmospheric Sciences, and Department of Biological
    [Show full text]
  • Russellosaurus Coheni N. Gen., N. Sp., a 92 Million-Year-Old Mosasaur from Texas (USA), and the Definition of the Parafamily Russellosaurina
    Netherlands Journal of Geosciences — Geologie en Mijnbouw | 84 - 3 | 321 - 333 | 2005 Russellosaurus coheni n. gen., n. sp., a 92 million-year-old mosasaur from Texas (USA), and the definition of the parafamily Russellosaurina M.J. Polcyn1'* & G.L. Bell Jr.2 1 Shuler Museum of Paleontology, Southern Methodist University, Dallas, Texas 75275, USA. 2 Guadalupe Mountains National Park, Salt Flat, Texas 79847, USA. * Corresponding author. Email: [email protected] Manuscript received: November 2004; accepted: January 2005 Abstract A new mosasaur, Russellosaurus coheni, is described from the Collignoniceras woollgari Zone (lower Middle Turonian) at Cedar Hill, Dallas County, Texas. At approximately 92 Ma, it is the oldest well-preserved mosasaur skull from North America. It possesses characters diagnostic of Plioplatecarpinae but retains numerous plesiomorphies as well. Phylogenetic analysis indicates a close relationship with Yaguarasaurus columbianus, and these two, together with Tethysaurus nopcsai, form a clade that occupies a position basal to the divergence of the subfamilies Tylosaurinae and Plioplatecarpinae. Russellosaurus coheni is proposed as the nominal taxon of a new mosasaur clade, parafamily taxon novum Russellosaurina, which includes Plioplatecarpinae, Tylosaurinae, their common ancestor and all descendants. Tethysaurus retains a plesiopedal limb and girdle morphology, and along with Russellosaurus and Yaguarasaurus, cranial plesiomorphies. Dallasaurus turneri, a temporally and geographically sympatric plesiopedal mosasaur, occupies a basal position within Mosasaurinae. This phyletic arrangement confirms that marine adaptations, such as development of paddle-like limbs, occurred independently in at least two lineages of mosasaurs, once within Mosasaurinae and once within Russellosaurina. Keywords: Mosasaur, Plioplatecarpinae, Tethysaurus, Turonian, Yaguarasaurus Introduction knowledge of the early evolutionary history of the group.
    [Show full text]
  • Papers Resulting from the First Moasaur Meeting, Maastricht, the Netherlands, May 2004
    Papers resulting from the First Moasaur Meeting, Maastricht, The Netherlands, May 2004. Bardet, N., Pereda Suberbiola, X., Iarochène, M., Amalik M., and Bouya, B. 2005. Durophagous Mosasauridae (Squamata) from the Upper Cretaceous phosphates of Morocco, with description of a new species of Globidens. Netherlands Journal of Geosciences / Geologie en Mijnbouw, 84(3), p. 167-176. Bell, G.L. Jr. and Polcyn, M.J. 2005. Dallasaurus turneri, a new primitive mosasauroid from the Middle Turonian of Texas and comments on the phylogeny of Mosasauridae (Squamata). Netherlands Journal of Geosciences / Geologie en Mijnbouw, 84(3), p. 177-194. Buchy, M.-C., Smith, K.T., Frey, E., Stinnesbeck, W., González González, A.H., Ifrim, C., López-Oliva, J.G. and Porras-Muzquiz, H. 2005. Annotated catalogue of marine squamates (Reptilia) from the Upper Cretaceous of northeastern Mexico. Netherlands Journal of Geosciences / Geologie en Mijnbouw, 84(3), p. 195-206. Caldwell, M.W. and Bell, G.L. Jr. 2005. Of German princes and North American rivers: Harlan’s lost mosasaur snout rediscovered. Netherlands Journal of Geosciences / Geologie en Mijnbouw, 84(3), p. 207-212. Caldwell, M.W. and Diedrich, C. G. 2005. Remains of Clidastes Cope, 1868, an unexpected mosasaur in the upper Campanian of NW Germany. Netherlands Journal of Geosciences / Geologie en Mijnbouw, 84(3), p. 213-220. Dutchak, A.R. 2005. A review of the taxonomy and systematics of aigialosaurs. Netherlands Journal of Geosciences / Geologie en Mijnbouw, 84(3), p. 221-230. Everhart. M.J. 2005. Tylosaurus kansasensis, a new species of tylosaurine (Squamata, Mosasauridae) from the Niobrara Chalk of western Kansas, USA.
    [Show full text]
  • Allometric Growth in the Skull of Tylosaurus Proriger (Squamata: Mosasauridae) and Its Taxonomic Implications Robert F
    Vertebrate Anatomy Morphology Palaeontology 6:75–90 75 ISSN 2292-1389 Allometric growth in the skull of Tylosaurus proriger (Squamata: Mosasauridae) and its taxonomic implications Robert F. Stewart1 and Jordan C. Mallon2,* 1Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada, K1S 5B6; [email protected] 2Palaeobiology, Canadian Museum of Nature, PO Box 3223, Station D, Ottawa, Ontario, Canada, K1P 6P4; [email protected] Abstract: Ontogeny—the growth and development of an organism—is among the more poorly understood aspects of the life history of mosasaurs, largely owing to a dearth of fossil material from young individuals. We describe the par- tial and nearly complete skulls of two subadult individuals of the mosasaurid Tylosaurus proriger from the upper Smoky Hills Chalk Member of the Niobrara Formation (upper Santonian) in Kansas. We include the more complete of the two specimens in an allometric analysis to better understand proportional changes in the skull through growth. Although our small sample size produces several instances of ‘soft isometry’, we recover the length of the edentulous rostrum as significantly negatively allometric, and quadrate height as significantly positively allometric. In light of our findings, we consider the question of whether T. kansasensis represents an immature ontogimorph of T. nepaeolicus, and find substan- tive evidence to reject this hypothesis. INTRODUCTION Seaway of North America (Williston 1898; Russell 1967; Everhart 2017). These are among the smallest skulls known Mosasauridae is a clade of carnivorous, mostly marine for the species, and they help to elucidate the allometric reptiles known from Upper Cretaceous deposits world- changes undergone by T. proriger through life.
    [Show full text]
  • Cranial Anatomy of a Maastrichtian (Upper Cretaceous) Mosasaur (Squamata, Mosasauridae) from North-East Mexico
    Revista Mexicana de Ciencias Geológicas,Cranial anatomy v. 24, núm.of a Maastrichtian 1, 2007, p. 89-103 mosasaur from north-east Mexico 89 Cranial anatomy of a Maastrichtian (Upper Cretaceous) mosasaur (Squamata, Mosasauridae) from north-east Mexico Marie-Céline Buchy1,*, Eberhard Frey2, Wolfgang Stinnesbeck3, and José Guadalupe López-Oliva4 1 Universität Karlsruhe, Geologisches Institut, Postfach 6980, D-76128 Karlsruhe, Germany. Current address: Museo del Desierto, Apartado Postal 307, 25000 Saltillo, Coahuila, Mexico. 2 Geowissenschaftliche Abteilung, Staatliches Museum für Naturkunde, Erbprinzenstrasse 13, D-76133 Karlsruhe, Germany. 3 Universität Karlsruhe, Geologisches Institut, Postfach 6980, D-76128 Karlsruhe, Germany. 4 Universidad Autónoma de Nuevo León, Facultad de Ciencias de la Tierra, Apartado Postal 104, 67700 Linares, N.L., Mexico. * [email protected] ABSTRACT We here describe the first mosasaur from Mexico known by significant cranial remains, from the late Early Maastrichtian Méndez Formation of Nuevo León, north-east Mexico. The specimen comprises a fragmentary skull and parts of the mandibles. Some anatomical features suggest a juvenile animal. The skull possesses a rostral tuberosity on the premaxilla, as well as a combination of features known from different mosasaur genera, like its frontopremaxillary suture situated caudal to the external naris, its prefrontal and postorbitofrontal being in contact lateral to the orbit, associated with the supra- and infrastapedial processes of its quadrate which almost contact one another. Despite being clearly distinct from any hitherto described mosasaur, the affinities of this specimen with other mosasaurs remain obscure, not only because of incompleteness, but also because of the poorly understood biological significance of the characters used for the classification of Mosasauridae.
    [Show full text]
  • Fossil Chimaeroid Remains (Chondrichthyes: Holocephali) from Williamsburg County, South Carolina, Usa
    Paludicola 8(1):37-48 September 2010 © by the Rochester Institute of Vertebrate Paleontology FOSSIL CHIMAEROID REMAINS (CHONDRICHTHYES: HOLOCEPHALI) FROM WILLIAMSBURG COUNTY, SOUTH CAROLINA, USA David J. Cicimurri Campbell Geology Museum, Clemson University, Clemson, South Carolina 29634 <[email protected]> ABSTRACT Three fossil holocephalian tooth plates have been recovered in Kingstree, Williamsburg County, South Carolina. All of the fossils were collected from a lag deposit containing a temporally mixed vertebrate assemblage. Two specimens, an incomplete left mandibular tooth plate and an incomplete left palatine tooth plate, are Edaphodon and compare favorably to E. mirificus. The third specimen is an incomplete and highly abraded right mandibular tooth plate from a very young individual that is questionably referred to Edaphodon. The tooth plates were associated with Cretaceous shark and dinosaur teeth, Paleocene shark and crocodilian teeth and turtle bones, and Plio-Pleistocene shark teeth and terrestrial mammal remains. The source of the Cretaceous fossils is arguably from Maastrichtian (late Cretaceous) strata (i.e., Peedee or Steel Creek formations), whereas Paleocene fossils are likely derived from the Danian (lower Paleocene) Rhems Formation. These fossils were probably concentrated together during Plio- Pleistocene sea level highstand, at which time the younger vertebrate material was deposited. INTRODUCTION Fossils from Clapp Creek came to the attention of Rudy Mancke (then Curator of Natural History at the Some of the geologic history of the South South Carolina State Museum) in the mid 1980s, and Carolina Coastal Plain is preserved as a complex soon thereafter he alerted Bruce Lampright (then of stratigraphic sequence that is far from completely Coastal Carolina University) to the fossil deposits to be understood.
    [Show full text]
  • The Bolca Lagerstätten: Shallow Marine Life in the Eocene
    Downloaded from http://jgs.lyellcollection.org/ by guest on September 27, 2021 Review focus Journal of the Geological Society Published online May 8, 2018 https://doi.org/10.1144/jgs2017-164 | Vol. 175 | 2018 | pp. 569–579 The Bolca Lagerstätten: shallow marine life in the Eocene Matt Friedman1* & Giorgio Carnevale2 1 Museum of Paleontology and Department of Earth and Environmental Sciences, University of Michigan, 1109 Geddes Ave, Ann Arbor, MI 48109-1079, USA 2 Dipartimento di Scienze della Terra, Università degli Studi di Torino, via Valperga Caluso 35, 10125, Torino, Italy M.F., 0000-0002-0114-7384 * Correspondence: [email protected] Abstract: The Eocene limestones around the Italian village of Bolca occur in a series of distinct localities providing a unique snapshot of marine life in the early Cenozoic. Famous for its fishes, the localities of Bolca also yield diverse invertebrate faunas and a rich, but relatively understudied flora. Most fossils from Bolca derive from the Pesciara and Monte Postale sites, which bear similar fossils but are characterized by slightly different taphonomic and environmental profiles. Although not precisely contemporaneous, the age of these principal localities is well constrained to a narrow interval within the Ypresian Stage, c. 50– 49 Ma. This places Bolca at a critical time in the evolutionary assembly of modern marine fish diversity and of reef communities more generally. Received 22 December 2017; revised 7 March 2018; accepted 8 March 2018 The rich fossil sites near Bolca, Italy provide a picture of life in a contains remains of crocodiles, turtles, snakes and plants. The warm, shallow marine setting during the early Eocene, roughly lignites of Vegroni yield a variety of plants.
    [Show full text]