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Cranial Anatomy, Taxonomic Implications
[Palaeontology, Vol. 55, Part 4, 2012, pp. 743–773] CRANIAL ANATOMY, TAXONOMIC IMPLICATIONS AND PALAEOPATHOLOGY OF AN UPPER JURASSIC PLIOSAUR (REPTILIA: SAUROPTERYGIA) FROM WESTBURY, WILTSHIRE, UK by JUDYTH SASSOON1, LESLIE F. NOE` 2 and MICHAEL J. BENTON1* 1School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen’s Road, Bristol BS8 1RJ, UK; e-mails: [email protected], [email protected] 2Geociencias, departamento de Fisica, Universidad de los Andes, Bogota´ DC, Colombia; e-mail: [email protected] *Corresponding author. Typescript received 5 December 2010; accepted in revised form 6 April 2011 Abstract: Complete skulls of giant marine reptiles of the genera. The two Westbury Pliosaurus specimens share many Late Jurassic are rare, and so the discovery of the 1.8-m- features, including the form of the teeth, but marked differ- long skull of a pliosaur from the Kimmeridge Clay Forma- ences in the snout and parietal crest suggest sexual dimor- tion (Kimmeridgian) of Westbury, Wiltshire, UK, is an phism; the present specimen is probably female. The large important find. The specimen shows most of the cranial size of the animal, the extent of sutural fusion and the and mandibular anatomy, as well as a series of pathological pathologies suggest this is an ageing individual. An erosive conditions. It was previously referred to Pliosaurus brachy- arthrotic condition of the articular glenoids led to pro- spondylus, but it can be referred reliably only to the genus longed jaw misalignment, generating a suite of associated Pliosaurus, because species within the genus are currently in bone and dental pathologies. -
First Occurrence of a Gigantic Pliosaurid Plesiosaur in The
Bull. Soc. géol. Fr., 2003, t. 174, no 3, pp. 271-278 First occurrence of a gigantic pliosaurid plesiosaur in the late Jurassic (Kimmeridgian) of Mexico MARIE-CÉLINE BUCHY1,EBERHARD FREY2,WOLFGANG STINNESBECK1 &JOSÉ GUADALUPE LÓPEZ-OLIVA3 Key words. – Kimmeridgian, Pliosauridae, Mexico, Palaeobiogeography. Abstract. – Reinvestigation of a partial vertebral column from the Kimmeridgian La Caja Formation of Mexico, housed in the University of Linares (Mexico), and previously attributed to a dinosaur, proves to be from a very large pliosaurid plesiosaur. This specimen represents the first plesiosaur described from the Jurassic of Mexico. Its length has been esti- mated at 15 metres and, as a juvenile, is considered to be one of the largest Jurassic marine reptiles. The remains of this animal are here described. The morphology of the vertebral column is not diagnostic beyond family level. Large pliosaur vertebrae of a similar size are known from the Upper Jurassic of Europe, and are often referred to the genera Liopleurodon or Simolestes but these identifications are based only upon the size of the centra and have no taxonomic justification. A portion of rostrum with teeth was discovered together with the vertebral column but is unfortunately now lost. The Mexican pliosaur fills geographical and chronological gaps between western Tethys and South American pliosaurs, and is an additional support to the hypothesis of a Hispanic corridor linking at least temporarily the NW Euro- pean marine province with the western South American marine (Pacific) realm during the late Jurassic. Première occurrence d’un plésiosaure pliosauride géant dans le Jurassique supérieur (Kimméridgien) du Mexique Mots clés. -
O'keefe, F. R. 2006
12 Neoteny and the Plesiomorphic Condition of the Plesiosaur Basicranium F. Robin O’Keefe Introduction Historically, the systematics of the Plesiosauria (Reptilia, Sauroptery- gia) were based largely on postcranial characters (Persson, 1963; Brown, 1981). Several factors account for this bias: plesiosaur skulls tend to be del- icate and are often crushed even when preserved, postcranial elements are relatively common and cranial elements are not, lack of knowledge about the relationships of stem-group sauropterygians, and lack of knowledge of plesiosaur cranial anatomy itself. However, recent detailed examinations of plesiosaur cranial anatomy have identified many characters of use in plesiosaur systematics (Brown, 1993; Cruickshank, 1994; Storrs & Taylor, 1996; Storrs, 1997; Carpenter, 1997; Evans, 1999; O’Keefe, 2001, 2004), and the systematics of the group have changed markedly in response (Carpenter, 1997; O’Keefe, 2001, 2004). The work of Rieppel and others has clarified the anatomy and relationships of stem-group sauropterygians (Storrs, 1991; see Rieppel, 2000, for review). This work has laid the anatomic and phylogenetic foundations for a better understanding of ple- siosaur cranial anatomy. The purpose of this paper is to describe the condition of the braincase in stratigraphically early and morphologically primitive plesiosaurs. In- formation on the braincase of plesiomorphic taxa is important because it establishes the polarity of characters occurring in more derived ple- siosaurs. This paper begins with a short review of braincase anatomy in stem-group sauropterygians. Data on braincase morphology of the ple- siomorphic plesiosaur genera Thalassiodracon and Eurycleidus are then presented and interpreted via comparison with other plesiosaurs, stem- group sauropterygians, and stem diapsids (Araeoscelis). -
Carpenter 1999 EL PLESIOSAURIO DE VILLA DE LEYVA (BOYACÁ, COLOMBIA)
Boletín de Geología Vol. 23, No. 38, Enero-Junio de 2001 Callawayasaurus colombiensis (Welles) Carpenter 1999 EL PLESIOSAURIO DE VILLA DE LEYVA (BOYACÁ, COLOMBIA). ¿UN NUEVO ESPÉCIMEN? Jerez Jaimes, J. H1.; Narváez Parra, E. X1. RESUMEN En los depósitos del Cretácico (Aptiano) de Villa de Leyva se han reportado dos especies de plesiosaurios, un pliosaurio Kronosaurus boyacensis Hampe 1992, y un plesiosaurio Callawayasaurus colombiensis (Welles) Carpenter, 1999 (= Alzadasaurus colombiensis Welles, 1962). Se realiza la determinación de un espécimen de elasmosaurio encontrado por los pobladores de la zona rural de Villa de Leyva en 1999 con base en material fotográfico del mismo, siendo muy probable que corresponda a la especie Callawayasaurus colombiensis (Welles) Carpenter, 1999. Palabras Claves: Cretácico, Plesiosaurios, Villa de Leyva. ABSTRACT In the deposits of the Cretaceous (Aptian) of Villa de Leyva two plesiosaurs species have been reported, a pliosaur Kronosaurus boyacensis Hampe 1992, and a plesiosaur Callawayasaurus colombiensis (Welles) Carpenter, 1999 (= Alzadasaurus colombiensis Welles, 1962). We carried out the determination of elasmosaur specimen found by the inhabitants of the rural area of Villa de Leyva in 1999, on the basis of photographic material of it. Probably it corresponds to the Callawayasaurus colombiensis specie (Welles) Carpenter, 1999. Key Words: Cretaceous, Plesiosaurs, Villa de Leyva. 1Biólogos, Calle 10A # 24-68 Bucaramanga, Santander (Colombia). Correo electrónico: [email protected] Callawayasaurus -
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. -
A Revision of the Classification of the Plesiosauria with a Synopsis of the Stratigraphical and Geographical Distribution Of
LUNDS UNIVERSITETS ARSSKRIFT. N. F. Avd. 2. Bd 59. Nr l. KUNGL. FYSIOGRAFISKA SÅLLSKAPETS HANDLINGAR, N. F. Bd 74. Nr 1. A REVISION OF THE CLASSIFICATION OF THE PLESIOSAURIA WITH A SYNOPSIS OF THE STRATIGRAPHICAL AND GEOGRAPHICAL DISTRIBUTION OF THE GROUP BY PER OVE PERSSON LUND C. W. K. GLEER UP Read before the Royal Physiographic Society, February 13, 1963. LUND HÅKAN OHLSSONS BOKTRYCKERI l 9 6 3 l. Introduction The sub-order Plesiosauria is one of the best known of the Mesozoic Reptile groups, but, as emphasized by KuHN (1961, p. 75) and other authors, its classification is still not satisfactory, and needs a thorough revision. The present paper is an attempt at such a revision, and includes also a tabular synopsis of the stratigraphical and geo graphical distribution of the group. Some of the species are discussed in the text (pp. 17-22). The synopsis is completed with seven maps (figs. 2-8, pp. 10-16), a selective synonym list (pp. 41-42), and a list of rejected species (pp. 42-43). Some forms which have been erroneously referred to the Plesiosauria are also briefly mentioned ("Non-Plesiosaurians", p. 43). - The numerals in braekets after the generic and specific names in the text refer to the tabular synopsis, in which the different forms are numbered in successional order. The author has exaroined all material available from Sweden, Australia and Spitzbergen (PERSSON 1954, 1959, 1960, 1962, 1962a); the major part of the material from the British Isles, France, Belgium and Luxembourg; some of the German spec imens; certain specimens from New Zealand, now in the British Museum (see LYDEK KER 1889, pp. -
A New Plesiosaur from the Lower Jurassic of Portugal and the Early Radiation of Plesiosauroidea
A new plesiosaur from the Lower Jurassic of Portugal and the early radiation of Plesiosauroidea EDUARDO PUÉRTOLAS-PASCUAL, MIGUEL MARX, OCTÁVIO MATEUS, ANDRÉ SALEIRO, ALEXANDRA E. FERNANDES, JOÃO MARINHEIRO, CARLA TOMÁS, and SIMÃO MATEUS Puértolas-Pascual, E., Marx, M., Mateus, O., Saleiro, A., Fernandes, A.E., Marinheiro, J., Tomás, C. and Mateus, S. 2021. A new plesiosaur from the Lower Jurassic of Portugal and the early radiation of Plesiosauroidea. Acta Palaeontologica Polonica 66 (2): 369–388. A new plesiosaur partial skeleton, comprising most of the trunk and including axial, limb, and girdle bones, was collected in the lower Sinemurian (Coimbra Formation) of Praia da Concha, near São Pedro de Moel in central west Portugal. The specimen represents a new genus and species, Plesiopharos moelensis gen. et sp. nov. Phylogenetic analysis places this taxon at the base of Plesiosauroidea. Its position is based on this exclusive combination of characters: presence of a straight preaxial margin of the radius; transverse processes of mid-dorsal vertebrae horizontally oriented; ilium with sub-circular cross section of the shaft and subequal anteroposterior expansion of the dorsal blade; straight proximal end of the humerus; and ventral surface of the humerus with an anteroposteriorly long shallow groove between the epipodial facets. In addition, the new taxon has the following autapomorphies: iliac blade with less expanded, rounded and convex anterior flank; highly developed ischial facet of the ilium; apex of the neural spine of the first pectoral vertebra inclined posterodorsally with a small rounded tip. This taxon represents the most complete and the oldest plesiosaur species in the Iberian Peninsula. -
A Large Rhomaleosaurid Pliosaur from the Upper Lias of Rutland Richard Forrest
A large Rhomaleosaurid Pliosaur from the Upper Lias of Rutland Richard Forrest Abstract: The fragmentary remains of a very large rhomaleosaurid pliosaur were retrieved during building works at Barnsdale Hall, Rutland. The limited material prevents clear identification at specific level, though on the basis of similarities of ratios of dimensions it shows closer affinity to Rhomaleosaurus arcuatus and R.victor than to R.cramptoni. Although scaling up from such fragmentary material is unreliable, the estimated length of this animal at 7.5 to 8 metres makes it possibly the largest Rhomaleosaurid pliosaur described to date. The fossil material broken end the shaft is oval in section, 148 mm wide and 96 mm deep. The head is 153 mm broad and The bones were excavated in 1988 by Mr. Roy 160 mm deep. Orientation can be determined by Draycott during construction of a retaining wall at rugosities from ridges for muscle attachment on the Barnsdale Hall, east of Rutland Water, in the county posterior side and the ventral surface. A deep hole in of the same name. An outer whorl of the ammonite the posterior muscle attachment presumably marks Hildoceras bifrons was found in association with the where a ligament was connected to the bone. There bones. It can therefore be placed with confidence in is slight taphonomic crushing around the trochanter. the bifrons Zone of the Upper Lias (Lower Jurassic, The surface is encrusted in places with a pyritised Toarcian, Whitbian). It is probable that much more deposit, which shows traces of tracks left by extensive remains of the animal were present at the scavengers post-mortem. -
Cranial Anatomy and Taxonomy of Dolichorhynchops Bonneri New
Marshall University Marshall Digital Scholar Biological Sciences Faculty Research Biological Sciences 2008 Cranial anatomy and taxonomy of Dolichorhynchops bonneri new combination, a polycotylid (Sauropterygia: Plesiosauria) from the Pierre Shale of Wyoming and South Dakota F. Robin O’Keefe Marshall University, [email protected] Follow this and additional works at: http://mds.marshall.edu/bio_sciences_faculty Part of the Animal Sciences Commons, and the Ecology and Evolutionary Biology Commons Recommended Citation O'Keefe, F. R. (2008). Cranial anatomy and taxonomy of Dolichorhynchops bonneri new combination, a polycotylid (Sauropterygia: Plesiosauria) from the Pierre Shale of Wyoming and South Dakota. Journal of Vertebrate Paleontology, 28(3), 664-676. This Article is brought to you for free and open access by the Biological Sciences at Marshall Digital Scholar. It has been accepted for inclusion in Biological Sciences Faculty Research by an authorized administrator of Marshall Digital Scholar. For more information, please contact [email protected], [email protected]. CRANIAL ANATOMY AND TAXONOMY OF DOLICHORHYNCHOPS BONNERI NEW COMBINATION, A POLYCOTYLID (SAUROPTERYGIA: PLESIOSAURIA) FROM THE PIERRE SHALE OF WYOMING AND SOUTH DAKOTA F. ROBIN O’KEEFE ABSTRACT The taxonomic identity of two well-preserved polycotylid plesiosaur skeletons from the Pierre Shale of far northern Wyoming and southern South Dakota has been controversial since their discovery. Originally referred to Dolichorhynchops osborni, the material was almost immediate-ly christened Trinacromerum bonneri Adams 1997; more recently the material has been referred to Polycotylus. Recent preparation of the well-preserved skull of one specimen permits detailed examination of the cranial morphology of this animal for the first time, and allows for its inclusion in a cladistic analysis of the Polycotylidae. -
Morphologic and Ontogenetic Patterns in Elasmosaur Neck Length, with Comments on the Taxonomic Utility of Neck Length Variables F
Marshall University Marshall Digital Scholar Biological Sciences Faculty Research Biological Sciences 6-2006 Morphologic and Ontogenetic Patterns in Elasmosaur Neck Length, with Comments on the Taxonomic Utility of Neck Length Variables F. Robin O’Keefe Marshall University, [email protected] Norton Hiller Follow this and additional works at: http://mds.marshall.edu/bio_sciences_faculty Part of the Aquaculture and Fisheries Commons, and the Ecology and Evolutionary Biology Commons Recommended Citation O’Keefe FR, Hiller N (2006) Morphologic and ontogenetic patterns in elasmosaur neck length, with comments on the taxonomic utility of neck length variables. Paludicola 5:206–229. This Article is brought to you for free and open access by the Biological Sciences at Marshall Digital Scholar. It has been accepted for inclusion in Biological Sciences Faculty Research by an authorized administrator of Marshall Digital Scholar. For more information, please contact [email protected], [email protected]. Paludicola 5(4):206-229 June 2006 by the Rochester Institute of Vertebrate Paleontology MORPHOLOGIC AND ONTOGENETIC PATTERNS IN ELASMOSAUR NECK LENGTH, WITH COMMENTS ON THE TAXONOMIC UTILITY OF NECK LENGTH VARIABLES F. Robin O'Keefe1 and Norton Hiller2 1Department of Anatomy, NYCOM 2 rm. 321, New York College of Osteopathic Medicine Old Westbury, New York 11568, [email protected] 2Canterbury Museum, Rolleston Avenue Christchurch, 8001 New Zealand, [email protected] ABSTRACT Elasmosaur cervical vertebrae are common fossils, but their taxonomic utility is limited due to a lack of understanding concerning their shape within and among taxa. In this paper, we analyze data from complete elasmosaur necks in an attempt to quantify and understand the variation in centrum dimensions. -
The Giant Pliosaurid That Wasn't—Revising the Marine Reptiles From
The giant pliosaurid that wasn’t—revising the marine reptiles from the Kimmeridgian, Upper Jurassic, of Krzyżanowice, Poland DANIEL MADZIA, TOMASZ SZCZYGIELSKI, and ANDRZEJ S. WOLNIEWICZ Madzia, D., Szczygielski, T., and Wolniewicz, A.S. 2021. The giant pliosaurid that wasn’t—revising the marine reptiles from the Kimmeridgian, Upper Jurassic, of Krzyżanowice, Poland. Acta Palaeontologica Polonica 66 (1): 99–129. Marine reptiles from the Upper Jurassic of Central Europe are rare and often fragmentary, which hinders their precise taxonomic identification and their placement in a palaeobiogeographic context. Recent fieldwork in the Kimmeridgian of Krzyżanowice, Poland, a locality known from turtle remains originally discovered in the 1960s, has reportedly provided additional fossils thought to indicate the presence of a more diverse marine reptile assemblage, including giant pliosaurids, plesiosauroids, and thalattosuchians. Based on its taxonomic composition, the marine tetrapod fauna from Krzyżanowice was argued to represent part of the “Matyja-Wierzbowski Line”—a newly proposed palaeobiogeographic belt comprising faunal components transitional between those of the Boreal and Mediterranean marine provinces. Here, we provide a de- tailed re-description of the marine reptile material from Krzyżanowice and reassess its taxonomy. The turtle remains are proposed to represent a “plesiochelyid” thalassochelydian (Craspedochelys? sp.) and the plesiosauroid vertebral centrum likely belongs to a cryptoclidid. However, qualitative assessment and quantitative analysis of the jaws originally referred to the colossal pliosaurid Pliosaurus clearly demonstrate a metriorhynchid thalattosuchian affinity. Furthermore, these me- triorhynchid jaws were likely found at a different, currently indeterminate, locality. A tooth crown previously identified as belonging to the thalattosuchian Machimosaurus is here considered to represent an indeterminate vertebrate. -
The First Record of Freshwater Plesiosaurian from the Middle
Gao et al. Journal of Palaeogeography (2019) 8:27 https://doi.org/10.1186/s42501-019-0043-5 Journal of Palaeogeography ORIGINALARTICLE Open Access The first record of freshwater plesiosaurian from the Middle Jurassic of Gansu, NW China, with its implications to the local palaeobiogeography Ting Gao, Da-Qing Li* , Long-Feng Li and Jing-Tao Yang Abstract Plesiosaurs are one of the common groups of aquatic reptiles in the Mesozoic, which mainly lived in marine environments. Freshwater plesiosaurs are rare in the world, especially from the Jurassic. The present paper reports the first freshwater plesiosaur, represented by four isolated teeth from the Middle Jurassic fluviolacustrine strata of Qingtujing area, Jinchang City, Gansu Province, Northwest China. These teeth are considered to come from one individual. The comparative analysis of the corresponding relationship between the body and tooth sizes of the known freshwater plesiosaur shows that Jinchang teeth represent a small-sized plesiosaurian. Based on the adaptive radiation of plesiosaurs and the palaeobiogeographical context, we propose a scenario of a river leading to the Meso-Tethys in the Late Middle Jurassic in Jinchang area, which may have provided a channel for the seasonal migration of plesiosaurs. Keywords: Freshwater plesiosaur, Middle Jurassic, Jinchang, Gansu Province, Palaeobiogeography 1 Introduction Warren 1980;Satoetal.2003; Kear 2012). Up to now, Plesiosaurs are one of the most familiar groups of Mesozoic the taxonomic affinities of most freshwater plesio- marine reptiles, which mainly lived in marine environ- saurs have remained unclear; some of them are re- ments. The records of plesiosaurs in non-marine deposits ferred to Plesiosauroidea (Cruickshank and Fordyce are sparse in comparison to those from marine sediments.