DOCSLIB.ORG

A New Record of the Pliosaur Brachauchenius Lucasi Williston, 1903 (Reptilia: Sauropterygia) of Turonian (Late Cretaceous) Age, Morocco

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A New Record of the Pliosaur Brachauchenius Lucasi Williston, 1903 (Reptilia: Sauropterygia) of Turonian (Late Cretaceous) Age, Morocco Geol. Mag.: page 1 of 11 c Cambridge University Press 2015 1 doi:10.1017/S0016756815000321 A new record of the pliosaur Brachauchenius lucasi Williston, 1903 (Reptilia: Sauropterygia) of Turonian (Late Cretaceous) age, Morocco ∗ D. ANGST ‡† & N. BARDET‡ ∗ LSCE–CEA–CNRS UMR 8212 CE Saclay l’Orme des Merisiers, 91191 Gif-sur-Yvette, France ‡Sorbonne Universités CR2P CNRS-MNHN-UMPC Paris 6, Département Histoire de la Terre, Muséum National d’Histoire Naturelle, CP 38, 8 rue Buffon, F-75005 Paris (Received 12 August 2014; accepted 1 May 2015) Abstract – The site of Goulmima (south Morocco) is well known for its rich marine fauna of Tur- onian age (Late Cretaceous). It has yielded a large variety of invertebrates but also of vertebrate taxa, represented by actinopterygians and marine reptiles including Plesiosauria (Sauropterygia) and Mosasauroidea (Squamata). The Plesiosauria are known so far by two major clades of Plesiosauroidea: the Elasmosauridae (Libonectes atlasense Buchy, 2005) and the Polycotylidae (Thililua longicollis, Bardet, Suberbiola & Jalil, 2003a; Manemergus angirostris Buchy, Metayer & Frey, 2005). Here we describe a new specimen of plesiosaur found in the same outcrop, differing from those previously cited and belonging to the other large plesiosaur clade, the Pliosauroidea. Comparison of this specimen with other Plesiosauria shows that it belongs to Brachauchenius lucasi Williston (1903), a species previously known only from the Cenomanian–Turonian stages of the Western Interior Seaway of North America and in the upper Barremian succession of northern South America (Colombia). The description of this species on a contemporaneous site of North Africa significantly expands its palaeobiogeographic dis- tribution. This discovery confirms the affinities between marine faunas of the Western Interior Seaway and those of North Africa at this time, and also permits a better understanding of the palaeobiology of the Goulmima outcrop. A discussion about the systematical status of Polyptychodon Owen, 1841 is also provided. Keywords: Sauropterygia, Pliosauridae, Turonian, Morocco, palaeobiogeography. 1. Introduction Schumacher, 2008 (paratype UNSM 50136) from Tur- onian Kansas (see Ketchum & Benson, 2010 for details, The Plesiosauria are a group of large marine pred- and online Supplementary Material Table S3 available ators known from latest Triassic to the end of Late at http://journals.cambridge.org/geo). Cretaceous time, when they become extinct during the Compared to other continents, the fossil record of biological crisis of the Cretaceous–Palaeogene (K–Pg) plesiosaurs is scarce in Africa where only five valid boundary (e.g. Vincent et al. 2011). Soon after their first taxa are known. All described from Cretaceous out- appearance in the fossil record at the end of Triassic crops, these are: the leptocleidid Leptocleidus capensis time, they underwent a spectacular radiation and be- (Andrews, 1911) from Early Cretaceous (Valanginian) came widespread both in time and space, being highly South Africa (Andrews, 1911; Cruickshank, 1997); the systematically and ecologically diversified throughout elasmosaurid Zarafasaura oceanis Vincent et al. 2011 the Jurassic–Cretaceous periods and found in all con- from latest Cretaceous (Maastrichtian) Morocco (Vin- tinents (Ketchum & Benson, 2010). cent et al. 2011); and the polycotylids Thililua longicol- During Late Cretaceous time the Plesiosauria were lis Bardet, Suberbiola & Jalil, 2003a and Manemergus particularly diversified and mainly represented by Ple- anguirostris Buchy, Metayer & Frey, 2005 and the elas- siosauroidea, known by the three families Elasmosaur- mosaurid Libonectes atlasense Buchy, 2005 described idae, Polycotylidae and Leptocleididae, as well as by from the lower Upper Cretaceous (Turonian) sediments the declining Pliosauroidea, known by the Pliosauridae of the Goulmima outcrop, southern Morocco (Bardet, only (Ketchum & Benson, 2010). Cretaceous pliosaurs Suberbiola & Jalil, 2003a; Buchy, 2005; Buchy, are only represented by: Kronosaurus Longman, 1924 Metayer & Frey, 2005). from Aptian–Albian Australia and Colombia; Bra- The Goulmima outcrop today represents the richest chauchenius Williston, 1903 from the Turonian West- plesiosaur site from Africa, with the two major clades ern Interior Seaway and Barremian Colombia (Hampe, of Cretaceous plesiosaurs represented as well as the 2005); and Megacephalosaurus eulerti Schumacher, elasmosaurids and the polycotylids. Here we describe Carpenter & Everhart, 2013 (FHSM VP321) and a new plesiosaur specimen from this outcrop belong- ing to the Pliosauridae, a clade previously undescribed †Author for correspondence: [email protected] from this area. http://journals.cambridge.org Downloaded: 17 Aug 2015 IP address: 37.163.202.226 2 D. ANGST & N. BARDET Figure 1. (a) Palaeogeographical location of the Goulmima area in southern Morocco (modified from Bardet, Suberbiola & Jalil, 2003a). (b) Probable stratigraphical range (Mammites horizon) of Brachauchenius lucasi specimen MNHN GOU 11 (modified from Cavin et al. 2010). Abbreviations: FHSM – The Sternberg Museum where the specimen could potentially come from (per- of Natural History, Hays, Kansas (USA); MNHN – sonal observation by NB). Muséum National d’Histoire Naturelle, Paris (France); In the Goulmima area, the Cenomanian–Turonian UNSM – University of Nebraska State Museum, Lin- limestone bar is easily identified. It is famous for its coln, Nebraska, USA. Turonian nodulous fossiliferous levels, including am- monites as well as marine vertebrates such as bony fishes (Cavin, 2001; Cavin et al. 2010) and large marine 2. Geographical and geological context reptiles, including the basal mosasauroid Tethysaurus In North Africa, the ‘middle’ part of the Cretaceous Bardet, Suberbiola & Jalil, 2003b and the three ple- (Aptian–Turonian) deposits is represented by a clas- siosaur taxa mentioned in the previous section (see sical trilogy forming in the landscape the recognizable Bardet et al. 2008 for details). Specimen MNHN cliff ‘Hamada’ that crops out extensively SW–NE from GOU 11 was probably preserved in such one large the Gulf of Agadir (Morocco) to the Gulf of Gabès nodule, although it remains impossible to confirm (Tunisia) (Choubert & Faure-Muret, 1962). as it was purchased already prepared (NB, personal The series classically includes, from the base to observation). the top: (1) red sandstones with crossed stratific- The fossils are generally very well preserved in small ations (Ifezouane Formation); (2) lagunar gypsous to very large concretion nodules that mainly occur marly sandstones and green marls (Aoufous Forma- near the top of a Cenomanian–Turonian limestone bar tion) (these two units are grouped into the classical (Fig. 1b). The main fossiliferous levels are located in ‘Continental Intercalaire’ of the French authors or Kem the ‘Unit 4’ (lower Turonian) of Ferrandini et al. (1985), Kem beds, Aptian–Albian in age); and (3) a marine cal- now reappraised by Ettachfini & Andreu (2004) as the careous massive bar (Akrabou Formation), represent- ‘Unit T2a’ of the Akrabou Formation (middle Turo- ing the beginning of the Cenomanian–Turonian trans- nian). Ammonites are rather frequent in these levels, gression in the area. especially belonging to the genus Mammites (see Cavin The specimen MNHN GOU 11 comes from the et al. 2010 for details). Goulmima region, located in the southern slope of the The Goulmima area was the centre of a basin which High Atlas of Morocco (Fig. 1a). Although its exact underwent large subsidence during the Cenomanian– location remains unknown because this specimen was Turonian transgression. It corresponds to an open mar- purchased, fieldwork has allowed us to locate several ine carbonated platform (Fig.1) related to the maximum fossiliferous localities near the villages of Tadighourst of the Cenomanian–Turonian transgressive phase and Asfla, north of Goulmima (Er-Rachidia Province), (Ferrandini et al. 1985), with dominant Tethyan but also http://journals.cambridge.org Downloaded: 17 Aug 2015 IP address: 37.163.202.226 A new record of a Cretaceous pliosaur, Morocco 3 Central Atlantic influences (Ettachfini & Andreu, 2004; Table 1. Measurements of the different elements of Cavin et al. 2010). Brachauchenius lucasi specimen MNHN GOU 11. NA – not applicable. Maximum Maximum 3. Systematic palaeontology Element length (mm) width (mm) Plesiosauria de Blainville, 1835 Mandible Pliosauroidea (Seeley, 1874) Welles, 1943 Dentary (dorsal view) 945 NA Pliosauroidea Seeley, 1874 Dentary (ventral view) 935 NA Symphysis (dorsal view) 250 NA Brachauchenius Williston, 1903 Symphysis (ventral view) 145 NA Brachauchenius lucasi Williston, 1903 Alveoli 1 right 32.9 31.2 Holotype: USNM 4989, skull, mandible, vertebrae and 2 right 34.7 33.4 ribs; Ottawa County, Kansas (USA); Greenhorn Lime- 3 right 35.1 34.2 4 right 35.1 33.4 stone, Turonian (Schumacher & Everhart, 2005). 5 right 35.7 31.5 6 right 28.9 33.1 Referred specimen: MNHN GOU 11, an incomplete 7 right 31.2 33.2 mandible; Goulmima region, Er-Rachidia province 8 right 39.0 36.7 (Morocco); probably Akrabou Formation (NB, per- 9 right 33.7 39.5 10 right 36.4 36.8 sonal observation), middle Turonian (Ettachfini & 11 right 30.6 34.8 Andreu, 2004). 12 right 34.4 32.6 13 right 30.8 33.3 14 right 31.5 32.1 15 right 31.7 36.5 4. Description 16 right 31.4 32.4 17 right 30.1 30.1 4.a. Mandible 18 right 30.1 30.0 19 right 29.2 27.4 The mandible preserved only both dentaries, broken 20 right 31.0 31.2 into 18 parts but remaining in connection.
Load more

Recommended publications
  • 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]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • On the Cranial Anatomy of the Polycotylid Plesiosaurs, Including New Material of Polycotylus Latipinnis, Cope, from Alabama F
    Marshall University Marshall Digital Scholar Biological Sciences Faculty Research Biological Sciences 2004 On the cranial anatomy of the polycotylid plesiosaurs, including new material of Polycotylus latipinnis, Cope, from Alabama 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. 2004. On the cranial anatomy of the polycotylid plesiosaurs, including new material of Polycotylus latipinnis, Cope, from Alabama. Journal of Vertebrate Paleontology 24(2):326–340. 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]. ON THE CRANIAL ANATOMY OF THE POLYCOTYLID PLESIOSAURS, INCLUDING NEW MATERIAL OF POLYCOTYLUS LATIPINNIS, COPE, FROM ALABAMA F. ROBIN O’KEEFE Department of Anatomy, New York College of Osteopathic Medicine, Old Westbury, New York 11568, U.S.A., [email protected] ABSTRACT—The cranial anatomy of plesiosaurs in the family Polycotylidae (Reptilia: Sauropterygia) has received renewed attention recently because various skull characters are thought to indicate plesiosauroid, rather than plio- sauroid, affinities for this family. New data on the cranial anatomy of polycotylid plesiosaurs is presented, and is shown to compare closely to the structure of cryptocleidoid plesiosaurs. The morphology of known polycotylid taxa is reported and discussed, and a preliminary phylogenetic analysis is used to establish ingroup relationships of the Cryptocleidoidea.
    [Show full text]
  • 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.
    [Show full text]
  • Mosasaurs Continuing from Last Time…
    Pliosaurs and Mosasaurs Continuing From Last Time… • Pliosauridae: the big marine predators of the Jurassic Pliosauridae • Some of the largest marine predators of all time, these middle Jurassic sauropterygians include such giants as Kronosaurus, Liopleurodon, Macroplata, Peloneustes, Pliosaurus, and Brachauchenius Pliosaur Mophology • While the number of cervical vertebrae is less than in plesiosaurs, there is still variation: Macroplata (29) vs. Kronosaurus (13) Pliosaur Morphology • Larger pliosaurs adopted a more streamlined body shape, like modern whales, with a large skull and compact neck, and generally the hind limbs were larger than the front, while plesiosaurs had larger forelimbs Pliosaur Morphology • Powerful limb girdles and large (banana sized) conical teeth helped pliosaurs eat larger, quicker prey than the piscivorous plesiosaurs Liopleurodon • NOT 25 m long in general (average of 40 feet), though perhaps certain individuals could reach that size, making Liopleurodon ferox the largest carnivore to ever live • Recent skull studies indicate that Liopleurodon could sample water in stereo through nostrils, locating scents much as we locate sound Cretaceous Seas • Breakup of Gondwana causes large undersea mountain chains to form, raising sea levels everywhere • Shallow seas encourage growth of corals, which increases calcium abundance and chalk formation • Warm seas and a gentle thermal gradient yield a hospitable environment to rays, sharks, teleosts, and the first radiation of siliceous diatoms Kronosaurus • Early Cretaceous
    [Show full text]
  • Late Cretaceous) of Morocco : Palaeobiological and Behavioral Implications Remi Allemand
    Endocranial microtomographic study of marine reptiles (Plesiosauria and Mosasauroidea) from the Turonian (Late Cretaceous) of Morocco : palaeobiological and behavioral implications Remi Allemand To cite this version: Remi Allemand. Endocranial microtomographic study of marine reptiles (Plesiosauria and Mosasauroidea) from the Turonian (Late Cretaceous) of Morocco : palaeobiological and behavioral implications. Paleontology. Museum national d’histoire naturelle - MNHN PARIS, 2017. English. NNT : 2017MNHN0015. tel-02375321 HAL Id: tel-02375321 https://tel.archives-ouvertes.fr/tel-02375321 Submitted on 22 Nov 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. MUSEUM NATIONAL D’HISTOIRE NATURELLE Ecole Doctorale Sciences de la Nature et de l’Homme – ED 227 Année 2017 N° attribué par la bibliothèque |_|_|_|_|_|_|_|_|_|_|_|_| THESE Pour obtenir le grade de DOCTEUR DU MUSEUM NATIONAL D’HISTOIRE NATURELLE Spécialité : Paléontologie Présentée et soutenue publiquement par Rémi ALLEMAND Le 21 novembre 2017 Etude microtomographique de l’endocrâne de reptiles marins (Plesiosauria et Mosasauroidea) du Turonien (Crétacé supérieur) du Maroc : implications paléobiologiques et comportementales Sous la direction de : Mme BARDET Nathalie, Directrice de Recherche CNRS et les co-directions de : Mme VINCENT Peggy, Chargée de Recherche CNRS et Mme HOUSSAYE Alexandra, Chargée de Recherche CNRS Composition du jury : M.
    [Show full text]
  • 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.
    [Show full text]
  • A Cladistic Analysis and Taxonomic Revision of the Plesiosauria (Reptilia: Sauropterygia) F
    Marshall University Marshall Digital Scholar Biological Sciences Faculty Research Biological Sciences 12-2001 A Cladistic Analysis and Taxonomic Revision of the Plesiosauria (Reptilia: Sauropterygia) F. Robin O’Keefe Marshall University, [email protected] Follow this and additional works at: http://mds.marshall.edu/bio_sciences_faculty Part of the Aquaculture and Fisheries Commons, and the Other Animal Sciences Commons Recommended Citation Frank Robin O’Keefe (2001). A cladistic analysis and taxonomic revision of the Plesiosauria (Reptilia: Sauropterygia). ). Acta Zoologica Fennica 213: 1-63. 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]. Acta Zool. Fennica 213: 1–63 ISBN 951-9481-58-3 ISSN 0001-7299 Helsinki 11 December 2001 © Finnish Zoological and Botanical Publishing Board 2001 A cladistic analysis and taxonomic revision of the Plesiosauria (Reptilia: Sauropterygia) Frank Robin O’Keefe Department of Anatomy, New York College of Osteopathic Medicine, Old Westbury, New York 11568, U.S.A Received 13 February 2001, accepted 17 September 2001 O’Keefe F. R. 2001: A cladistic analysis and taxonomic revision of the Plesio- sauria (Reptilia: Sauropterygia). — Acta Zool. Fennica 213: 1–63. The Plesiosauria (Reptilia: Sauropterygia) is a group of Mesozoic marine reptiles known from abundant material, with specimens described from all continents. The group originated very near the Triassic–Jurassic boundary and persisted to the end- Cretaceous mass extinction. This study describes the results of a specimen-based cladistic study of the Plesiosauria, based on examination of 34 taxa scored for 166 morphological characters.
    [Show full text]
  • The Macroevolutionary Landscape of Short-Necked Plesiosaurians Collapsed to a Unimodal Distribution
    www.nature.com/scientificreports OPEN The macroevolutionary landscape of short‑necked plesiosaurians Valentin Fischer1*, Jamie A. MacLaren1, Laura C. Soul2, Rebecca F. Bennion1,3, Patrick S. Druckenmiller4 & Roger B. J. Benson5 Throughout their evolution, tetrapods have repeatedly colonised a series of ecological niches in marine ecosystems, producing textbook examples of convergent evolution. However, this evolutionary phenomenon has typically been assessed qualitatively and in broad‑brush frameworks that imply simplistic macroevolutionary landscapes. We establish a protocol to visualize the density of trait space occupancy and thoroughly test for the existence of macroevolutionary landscapes. We apply this protocol to a new phenotypic dataset describing the morphology of short‑necked plesiosaurians, a major component of the Mesozoic marine food webs (ca. 201 to 66 Mya). Plesiosaurians evolved this body plan multiple times during their 135-million-year history, making them an ideal test case for the existence of macroevolutionary landscapes. We fnd ample evidence for a bimodal craniodental macroevolutionary landscape separating latirostrines from longirostrine taxa, providing the frst phylogenetically-explicit quantitative assessment of trophic diversity in extinct marine reptiles. This bimodal pattern was established as early as the Middle Jurassic and was maintained in evolutionary patterns of short‑necked plesiosaurians until a Late Cretaceous (Turonian) collapse to a unimodal landscape comprising longirostrine forms with novel morphologies. This study highlights the potential of severe environmental perturbations to profoundly alter the macroevolutionary dynamics of animals occupying the top of food chains. Amniotes are ’land vertebrates’, but have nevertheless undergone at least 69 independent evolutionary transi- tions from land into aquatic environments 1. Sea-going (marine) amniotes are textbook examples of inter- and intraclade convergent evolution, with repeated acquisitions of short, hydrodynamic body plans 2–9.
    [Show full text]
  • Revision of the Genus Styxosaurus and Relationships of the Late Cretaceous Elasmosaurids (Sauropterygia: Plesiosauria) of the Western Interior Seaway
    Marshall University Marshall Digital Scholar Theses, Dissertations and Capstones 2020 Revision of the Genus Styxosaurus and Relationships of the Late Cretaceous Elasmosaurids (Sauropterygia: Plesiosauria) of the Western Interior Seaway Elliott Armour Smith Follow this and additional works at: https://mds.marshall.edu/etd Part of the Biology Commons, Paleobiology Commons, and the Paleontology Commons REVISION OF THE GENUS STYXOSAURUS AND RELATIONSHIPS OF THE LATE CRETACEOUS ELASMOSAURIDS (SAUROPTERYGIA: PLESIOSAURIA) OF THE WESTERN INTERIOR SEAWAY A thesis submitted to the Graduate College of Marshall University In partial fulfillment of the requirements for the degree of Master of Science In Biological Sciences by Elliott Armour Smith Approved by Dr. F. Robin O’Keefe, Committee Chairperson Dr. Habiba Chirchir, Committee Member Dr. Herman Mays, Committee Member Marshall University May 2020 ii © 2020 Elliott Armour Smith ALL RIGHTS RESERVED iii DEDICATION Dedicated to my loving parents for supporting me on my journey as a scientist. iv ACKNOWLEDGEMENTS I would like to thank Dr. Robin O’Keefe for serving as my advisor, and for his constant mentorship and invaluable contributions to this manuscript. I would like to thank Dr. Herman Mays and Dr. Habiba Chirchir for serving on my committee and providing immensely valuable feedback on this manuscript and the ideas within. Thanks to the Marshall University Department of Biological Sciences for travel support. I would like to thank curators Ross Secord (University of Nebraska), Chris Beard (University of Kansas), Tylor Lyson (Denver Museum of Nature and Science), and Darrin Paginac (South Dakota School of Mines and Technology) for granting access to fossil specimens. Thanks to Joel Nielsen (University of Nebraska State Museum), Megan Sims (University of Kansas), Kristen MacKenzie (Denver Museum of Nature and Science) for facilitating access to fossil specimens.
    [Show full text]
  • And a Review of the Upper Cretaceous Plesiosaurs from Europe
    BULLETIN DE L'INSTITUT ROYAL DES SCIENCES NATURELLES DE BELGIQUE SCIENCES DE LA TERRE, 65: 179-186, 1995 BULLETIN VAN HET KONINKLIJK BELGISCH INSTITUUT VOOR NATUURWETENSCHAPPEN, AARDWETENSCHAPPEN, 65: 179-186, 1995 Plesiosaurus houzeaui D ollo, 1909from the Upper Campanian of Ciply (Belgium) and a review of the Upper Cretaceous plesiosaurs from Europe. by Nathalie BARDET & Pascal GODEFROIT Abstract other hand, only scant plesiosaur material has been dis­ covered in the Upper Cretaceous of Europe (see discus­ The holotype of Plesiosaurus houzeaui Dollo, 1909 consists of ple- sion). siosaurian bones, discovered in the Spiennes Chalk (Upper Campa­ nian) of the Ciply area (Mons Basin, Belgium). The description of the Marine Cretaceous deposits are well exposed in the type material shows that Plesiosaurus houzeaui is an invalid species Mons Basin (western Belgium). During the second half of based on heterogeneous elasmosaurid and also probably non-elasmo- the 19th century, the Maastrichtian Ciply Phosphatic saurid plesiosaurian material. A review of plesiosaurian material pre­ viously described from the Upper Cretaceous of Europe indicates that Chalk was intensively quarried in this area for manufac­ Elasmosauridae and Pliosauridae are represented. Polyptychodon is the ture of agricultural fertilizers (Leclercq & Bouko, only valid genus of plesiosaur from the Upper Cretaceous of Europe. 1985). Numerous fossil vertebrates were discovered in various quarries, mainly in Ciply. These collections, in­ Key-words- Plesiosaurus houzeaui. Plesiosauria, Upper Cretaceous, Europe, revision. cluding fishes, turtles and 52 relatively complete mosa- saur skeletons, were transferred to the “Musée royal d’Histoire naturelle” (now, Institut royal des Sciences naturelles de Belgique = IRSNB). Résumé In 1909,D o l l o mentioned the discovery of plesiosaur bones in the Upper Cretaceous of Belgium.
    [Show full text]