DOCSLIB.ORG

Postcrania of Large Dissorophid Temnospondyls from Richards Spur, Oklahoma

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Postcrania of Large Dissorophid Temnospondyls from Richards Spur, Oklahoma Foss. Rec., 21, 79–91, 2018 https://doi.org/10.5194/fr-21-79-2018 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. Postcrania of large dissorophid temnospondyls from Richards Spur, Oklahoma Bryan M. Gee and Robert R. Reisz Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, Ontario L5L 1C6, Canada Correspondence: Bryan M. Gee ([email protected]) Received: 27 October 2017 – Revised: 25 January 2018 – Accepted: 14 February 2018 – Published: 22 March 2018 Abstract. The early Permian karst system near Richards ements may reflect a taphonomic bias, but it is also likely to Spur, Oklahoma preserves a diverse assemblage of terrestrial be, at least in part, reflective of the historic sourcing of spec- dissorophoid temnospondyls. Here we report the presence of imens from local collectors and a historic emphasis on both a large-bodied dissorophine dissorophid that is represented the collection and study of cranial materials by amateur and by an articulated anterior trunk region, including a partial professional palaeontologists alike. The postcranial skeleton pectoral girdle, a ribcage characterized by extremely devel- of Doleserpeton is well-characterized (e.g., Sigurdsen and oped uncinate processes, and a rare, completely articulated Bolt, 2010), and description of partial, articulated postcra- pes. This represents the first documentation of the clade at nia of C. morrisi is forthcoming (Gee and Reisz, 2018), but the locality. Previously, dissorophids were represented only the postcrania of all other taxa are poorly known. All of the by the eucacopine Cacops. A complete pelvic girdle with postcranial material referred to A. dunni (Polley and Reisz, hindlimbs is also referred to Cacops and represents the first 2011) is isolated and is assigned based on proximity to the material of the posterior trunk region to be described from holotype skull and similarity to the genotype. Isolated limb the genus at Richards Spur. These specimens expand the tax- elements referred to Cacops sp. and Acheloma sp. were de- onomic diversity known from the site and provide significant, scribed by Sullivan et al. (2000). Postcrania of Pasawioops, well-preserved postcranial material that improves the charac- Tersomius, and C. woehri are unknown. In addition to the terization of dissorophid postcranial anatomy. challenges posed by taphonomic and collection biases, at- tempts to differentiate and to contextualize isolated postcra- nial elements can also be confounded by conservatism within the clade. This often results in skewed descriptions that fo- 1 Introduction cus primarily on cranial elements and sutural patterns. Ac- cordingly, the thorough description of articulated postcrania The early Permian karst deposits near Richards Spur, Ok- of large-bodied dissorophids is important for augmenting the lahoma preserve a diverse array of terrestrial dissorophoid record and the understanding of dissorophoid postcrania. temnospondyls. These include three amphibamids (Doleser- Here we describe a large block that contains the well- peton annectens, Pasawioops mayi, and Tersomius dolesen- preserved postcrania of two dissorophids (OMNH 73522). sis), two dissorophids (Cacops morrisi and C. woehri), and The material consists of two skeletal regions: (1) a predom- one trematopid (Acheloma dunni) (Bolt, 1969; Fröbisch and inantly anterior trunk region (articulated forelimbs, pectoral Reisz, 2008, 2012; Reisz et al., 2009; Polley and Reisz, 2011; girdle, anterior trunk vertebral elements, and ribs) that is also Anderson and Bolt, 2013). This dissorophoid assemblage is associated with a hindlimb and a pes (Figs. 1–6), and (2) a the richest of any early Permian locality and is possibly the posterior trunk region (complete pelvic girdle, articulated best representation of an early Permian community of terres- hindlimbs, disarticulated phalanges) (Fig. 7). The presence trial temnospondyls, but one of the principal challenges con- of three hindlimbs indicates that at least two individuals are founding a better understanding of this unique occurrence is represented. Postcranial synapomorphies permit a referral of the paucity of postcranial elements. The scarcity of such el- Published by Copernicus Publications on behalf of the Museum für Naturkunde Berlin. 80 B. M. Gee and R. R. Reisz: Postcrania of large dissorophid temnospondyls from Richards Spur both individuals to the clade Olsoniformes, which comprises anterior to the anterior trunk region. For clarity throughout the large-bodied, terrestrial dissorophids and trematopids; the paper, the predominantly anterior trunk region, divided any further resolution is more tentative. A large humerus between the two blocks, is referred to as OMNH 73522a, and lacking a supinator process allows for the anterior trunk re- the posterior trunk region, found only on the larger block, gion to be refined to the Dissorophidae, and several features is referred to as OMNH 73522b. Also present between the that distinguish the material from Cacops permit a tentative blocks are a large number of amniote elements, including identification as a dissorophine. The posterior trunk region partial varanopid and captorhinid skulls on the underside, can similarly only be tentatively referred, but the material is and a captorhinid manus, a captorhinid pes, and a varanopid identical to that of Cacops and can be differentiated from pes on the same side as the dissorophoid material. These are other olsoniforms on the basis of several features. Although not described or figured here. Material was prepared using Cacops is one of the better-known dissorophoids from the pin vises and air scribes. Figures were prepared using Adobe locality, its characterization has been based mostly on cra- Photoshop and Illustrator CS6. nial material (Reisz et al., 2009; Fröbisch and Reisz, 2012; Fröbisch et al., 2015) and the anterior trunk region (Gee and 2.2 Locality Reisz, 2018). The newly described pelvis that we refer to the taxon is informative for expanding the characterized skeletal The material is sourced from the early Permian (Sakmarian) regions of the Richards Spur eucacopines. karst deposits at the Dolese Brothers Limestone Quarry near Dissorophines, known almost exclusively from the Texas Richards Spur, OK, USA. red beds, have never been previously documented at Richards Spur. Their putative presence expands the dissorophoid as- 2.3 Institutional abbreviations semblage at the locality and adds a new complexity to the OMNH: Sam Noble Oklahoma Museum of Natural History, community structure that is preserved there. Well-preserved Norman, OK, USA and well-described postcrania are known from only a hand- ful of dissorophid taxa from any locality (e.g., Cacops and Dissorophus from the Texas red beds). Furthermore, the ten- 3 Description dency of past workers to simply characterize more isolated or fragmentary postcranial elements as being comparable or 3.1 OMNH 73522a identical to Cacops has severely limited comparative studies of dissorophid postcrania. The quality of the material pre- 3.1.1 Pectoral girdle sented here, in conjunction with a thorough, comparative de- scription, provides a broader foundation for future work on The pectoral girdle of OMNH 73522a consists of one clei- dissorophids. In particular, the extremely developed uncinate thrum and two scapulacoracoids (Figs. 1–2). Two olsoni- processes of the ribs and the articulated pes are intriguing and form synapomorphies of the postcrania inform the taxonomic important contributions to our understanding of the ontogeny identification: (1) the proportions of the scapulacoracoid (at and taxonomy of olsoniform dissorophoids. least three times longer than they are wide) and (2) the dor- sal overlap of the scapulacoracoid by the cleithrum. The left girdle is only partially exposed at the dorsal region in lateral 2 Materials and methods profile (Figs. 1–2). From the dorsal margin of the scapulaco- racoid, the flat portion of the cleithrum curves anteroventrally 2.1 Materials to follow the anterior margin of the former, thickening along the posterior margin to form a thin, blade-like ventral exten- The dissorophoid material spans a single original block sion that continues down the anterior margin of the scapula- (OMNH 73522) that is presently divided disproportion- coracoid. This ventral process extends nearly to the glenoid, ately between two blocks. The larger piece contains ma- whereas the dorsal blade terminates abruptly just ventral to terial of two individuals: (1) the vast majority of an an- the curve. The right girdle is fully exposed in posterior pro- terior trunk region (vertebrae, ribs, forelimbs, pectoral gir- file, with features such as the glenoid, the supraglenoid fossa, dle) with hindlimbs and pes, and (2) the entirety of a pelvic and the glenoid and coracoid foramina exposed (Figs. 1–2). girdle region (including hindlimbs, probable pes elements) No corresponding right cleithrum is present. The fusion of (Sect. 3.1). The smaller piece contains the anteriormost the scapula and the coracoid without an identifiable suture vertebral column (including the atlas and the axis) and a demarcating their original contact is indicative of relative humerus that belong to the same individual as the anterior maturity. trunk region on the large block (Sect. 3.2). The material be- The pectoral elements of olsoniforms are highly con- longs to at least two individuals, as evidenced by three paired served. Minor variation in proportions
Load more

Recommended publications
  • Dissorophus Cope
    DISSOROPHUS COPE S. W. WILLISTON The University of Chicago The material herein described and figured was collected by the writer from the upper or Clear Fork Division of the Texas Red-beds on Coffee Creek, in August, 1909. It comprises a nearly complete skull, but little distorted, the two scapulae with attached cleithra, neither complete, but the two supplementing each other nearly per- fectly; the two complete clavicles attached to the incomplete inter- clavicle; the two humeri, one complete save for the capitellar angle, the other with the distal part quite complete and the proximal portion missing; two attached proximal carpals, several vertebrae and frag- ments of ribs, the nearly complete carapace, a broken and somewhat distorted pelvis, a femur, and fragments of epipodial bones. For the most part, the surface of the skull is unimpaired, showing deep, almost circular pits, with narrow, reticulating ridges between them. The pittings seem to be most pronounced in the upper pos- terior part. There are no indications of mucous grooves, and I am convinced that, were they originally present, evidences of them would be apparent. Nor, as in the case of the skulls of Cacops, can I distinguish the sutures. The skull is very broad posteriorly, with a rounded, obtuse muzzle. The orbits are situated about midway in its length, they are rather small, nearly circular in outline, and broadly separated. The table of the cranium, back of the orbits, is rather broader than long, a little wider anteriorly, with a broad emargination behind; it is nearly plane, with its margins elevated. The parietal foramen is situated a little back of a line drawn through the posterior margin of the orbits.
    [Show full text]
  • Ontogenetic Change in the Temporal Region of the Early Permian Parareptile Delorhynchus Cifellii and the Implications for Closure of the Temporal Fenestra in Amniotes
    RESEARCH ARTICLE Ontogenetic Change in the Temporal Region of the Early Permian Parareptile Delorhynchus cifellii and the Implications for Closure of the Temporal Fenestra in Amniotes Yara Haridy*, Mark J. Macdougall, Diane Scott, Robert R. Reisz Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada * [email protected] a11111 Abstract A juvenile specimen of Delorhynchus cifellii, collected from the Early Permian fissure-fill deposits of Richards Spur, Oklahoma, permits the first detailed study of cranial ontogeny in this parareptile. The specimen, consisting of a partially articulated skull and mandible, exhib- OPEN ACCESS its several features that identify it as juvenile. The dermal tuberosities that ornament the dor- Citation: Haridy Y, Macdougall MJ, Scott D, Reisz sal side and lateral edges of the largest skull of D. cifellii specimens, are less prominent in RR (2016) Ontogenetic Change in the Temporal the intermediate sized holotype, and are absent in the new specimen. This indicates that the Region of the Early Permian Parareptile new specimen represents an earlier ontogenetic stage than all previously described mem- Delorhynchus cifellii and the Implications for bers of this species. In addition, the incomplete interdigitation of the sutures, most notably Closure of the Temporal Fenestra in Amniotes. PLoS ONE 11(12): e0166819. doi:10.1371/journal. along the fronto-nasal contact, plus the proportionally larger sizes of the orbit and temporal pone.0166819 fenestrae further support an early ontogenetic stage for this specimen. Comparisons Editor: Thierry Smith, Royal Belgian Institute of between this juvenile and previously described specimens reveal that the size and shape of Natural Sciences, BELGIUM the temporal fenestra in Delorhynchus appear to vary through ontogeny, due to changes in Received: July 18, 2016 the shape and size of the bordering cranial elements.
    [Show full text]
  • Stuttgarter Beiträge Zur Naturkunde
    S^5 ( © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at Stuttgarter Beiträge zur Naturkunde Serie B (Geologie und Paläontologie) Herausgeber: Staatliches Museum für Naturkunde, Rosenstein 1, D-70191 Stuttgart Stuttgarter Beitr. Naturk. Ser. B Nr. 278 175 pp., 4pls., 54figs. Stuttgart, 30. 12. 1999 Comparative osteology oi Mastodonsaurus giganteus (Jaeger, 1828) from the Middle Triassic (Lettenkeuper: Longobardian) of Germany (Baden-Württemberg, Bayern, Thüringen) By Rainer R. Schoch, Stuttgart With 4 plates and 54 textfigures Abstract Mastodonsaurus giganteus, the most abundant and giant amphibian of the German Letten- keuper, is revised. The study is based on the excellently preserved and very rieh material which was excavated during road construction in 1977 near Kupferzeil, Northern Baden- Württemberg. It is shown that there exists only one diagnosable species of Mastodonsaurus, to which all Lettenkeuper material can be attributed. All finds from other horizons must be referred to as Mastodonsauridae gen. et sp. indet. because of their fragmentary Status. A sec- ond, definitely diagnostic genus of this family is Heptasaurus from the higher Middle and Upper Buntsandstein. Finally a diagnosis of the family Mastodonsauridae is provided. Ä detailed osteological description of Mastodonsaurus giganteus reveals numerous un- known or formerly inadequately understood features, yielding data on various hitherto poor- ly known regions of the skeleton. The sutures of the skull roof, which could be studied in de- tail, are significantly different from the schemes presented by previous authors. The endocra- nium and mandible are further points of particular interest. The palatoquadrate contributes a significant part to the formation of the endocranium by an extensive and complicated epi- pterygoid.
    [Show full text]
  • Cacopsamphibiala373bolt.Pdf
    v UNIVtRSlT Cp ILLINOIS I 5RARY AT URBANA-CHAMPAIGN L IOLOGY CO CO /&£^<-*x~*yw FIELDIANA Geology Published by Field Museum of Natural History Volume 37, No. 3 June 30, 1977 Cacops (Amphibia: Labyrinthodontia) From the Fort Sill Locality, Lower Permian of Oklahoma the The Library of John R. Bolt Assistant Curator, Fossil Reptiles and Amphibians 1978 Field Museum of Natural History MRRU ABSTRACT at Urbana-ChamP«* The armored dissorophid (Super family Dissorophoidea ) labyrinthodont amphi- bian Cacops aspidephorus is unusual in having a large otic notch closed posteriorly by the tabular. Cacops was previously known only from the "Cacops Bone Bed," Lower Permian of Texas. Poor preservation makes this material difficult to study. Excellently preserved, though disarticulated, Cacops material has now been recov- ered from the Fort Sill fissure fills, which are probably very close in age to the "Ca- cops Bone Bed." Identification of the Fort Sill material as Cacops is based on pala- tines (primarily), armor scutes, and quadrates; the latter are here described for the first time from Fort Sill. The Cacops quadrate resembles that of other dissorophoids in having a posterodorsal process, which is unusual in the marked anterior expan- sion of its dorsal end. Comparison with other dissorophoids having a closed otic notch shows that Cacops is not unique in this anterior expansion of the process. Orientation of the process can apparently be used to distinguish trematopsids with a slit-like, closed (by the tabular) otic notch, from dissorophids. At least one such trematopsid occurs at Fort Sill, and resembles Cacops in anterior expansion of the process.
    [Show full text]
  • Phylogeny and Evolution of the Dissorophoid Temnospondyls
    Journal of Paleontology, 93(1), 2019, p. 137–156 Copyright © 2018, The Paleontological Society. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/ licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. 0022-3360/15/0088-0906 doi: 10.1017/jpa.2018.67 The putative lissamphibian stem-group: phylogeny and evolution of the dissorophoid temnospondyls Rainer R. Schoch Staatliches Museum für Naturkunde, Rosenstein 1, D-70191 Stuttgart, Germany 〈[email protected]〉 Abstract.—Dissorophoid temnospondyls are widely considered to have given rise to some or all modern amphibians (Lissamphibia), but their ingroup relationships still bear major unresolved questions. An inclusive phylogenetic ana- lysis of dissorophoids gives new insights into the large-scale topology of relationships. Based on a TNT 1.5 analysis (33 taxa, 108 characters), the enigmatic taxon Perryella is found to nest just outside Dissorophoidea (phylogenetic defintion), but shares a range of synapomorphies with this clade. The dissorophoids proper are found to encompass a first dichotomy between the largely paedomorphic Micromelerpetidae and all other taxa (Xerodromes). Within the latter, there is a basal dichotomy between the large, heavily ossified Olsoniformes (Dissorophidae + Trematopidae) and the small salamander-like Amphibamiformes (new taxon), which include four clades: (1) Micropholidae (Tersomius, Pasawioops, Micropholis); (2) Amphibamidae sensu stricto (Doleserpeton, Amphibamus); (3) Branchiosaur- idae (Branchiosaurus, Apateon, Leptorophus, Schoenfelderpeton); and (4) Lissamphibia. The genera Platyrhinops and Eos- copus are here found to nest at the base of Amphibamiformes. Represented by their basal-most stem-taxa (Triadobatrachus, Karaurus, Eocaecilia), lissamphibians nest with Gerobatrachus rather than Amphibamidae, as repeatedly found by former analyses.
    [Show full text]
  • Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha)
    Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha) by Richard Kissel A thesis submitted in conformity with the requirements for the degree of doctor of philosophy Graduate Department of Ecology & Evolutionary Biology University of Toronto © Copyright by Richard Kissel 2010 Morphology, Phylogeny, and Evolution of Diadectidae (Cotylosauria: Diadectomorpha) Richard Kissel Doctor of Philosophy Graduate Department of Ecology & Evolutionary Biology University of Toronto 2010 Abstract Based on dental, cranial, and postcranial anatomy, members of the Permo-Carboniferous clade Diadectidae are generally regarded as the earliest tetrapods capable of processing high-fiber plant material; presented here is a review of diadectid morphology, phylogeny, taxonomy, and paleozoogeography. Phylogenetic analyses support the monophyly of Diadectidae within Diadectomorpha, the sister-group to Amniota, with Limnoscelis as the sister-taxon to Tseajaia + Diadectidae. Analysis of diadectid interrelationships of all known taxa for which adequate specimens and information are known—the first of its kind conducted—positions Ambedus pusillus as the sister-taxon to all other forms, with Diadectes sanmiguelensis, Orobates pabsti, Desmatodon hesperis, Diadectes absitus, and (Diadectes sideropelicus + Diadectes tenuitectes + Diasparactus zenos) representing progressively more derived taxa in a series of nested clades. In light of these results, it is recommended herein that the species Diadectes sanmiguelensis be referred to the new genus
    [Show full text]
  • Early Tetrapod Relationships Revisited
    Biol. Rev. (2003), 78, pp. 251–345. f Cambridge Philosophical Society 251 DOI: 10.1017/S1464793102006103 Printed in the United Kingdom Early tetrapod relationships revisited MARCELLO RUTA1*, MICHAEL I. COATES1 and DONALD L. J. QUICKE2 1 The Department of Organismal Biology and Anatomy, The University of Chicago, 1027 East 57th Street, Chicago, IL 60637-1508, USA ([email protected]; [email protected]) 2 Department of Biology, Imperial College at Silwood Park, Ascot, Berkshire SL57PY, UK and Department of Entomology, The Natural History Museum, Cromwell Road, London SW75BD, UK ([email protected]) (Received 29 November 2001; revised 28 August 2002; accepted 2 September 2002) ABSTRACT In an attempt to investigate differences between the most widely discussed hypotheses of early tetrapod relation- ships, we assembled a new data matrix including 90 taxa coded for 319 cranial and postcranial characters. We have incorporated, where possible, original observations of numerous taxa spread throughout the major tetrapod clades. A stem-based (total-group) definition of Tetrapoda is preferred over apomorphy- and node-based (crown-group) definitions. This definition is operational, since it is based on a formal character analysis. A PAUP* search using a recently implemented version of the parsimony ratchet method yields 64 shortest trees. Differ- ences between these trees concern: (1) the internal relationships of aı¨stopods, the three selected species of which form a trichotomy; (2) the internal relationships of embolomeres, with Archeria
    [Show full text]
  • Morphology and Evolutionary Significance of the Atlas−Axis Complex in Varanopid Synapsids
    Morphology and evolutionary significance of the atlas−axis complex in varanopid synapsids NICOLÁS E. CAMPIONE and ROBERT R. REISZ Campione, N.E. and Reisz, R.R. 2011. Morphology and evolutionary significance of the atlas−axis complex in varanopid synapsids. Acta Palaeontologica Polonica 56 (4): 739–748. The atlas−axis complex has been described in few Palaeozoic taxa, with little effort being placed on examining variation of this structure within a small clade. Most varanopids, members of a clade of gracile synapsid predators, have well pre− served atlas−axes permitting detailed descriptions and examination of morphological variation. This study indicates that the size of the transverse processes on the axis and the shape of the axial neural spine vary among members of this clade. In particular, the small mycterosaurine varanopids possess small transverse processes that point posteroventrally, and the axial spine is dorsoventrally short, with a flattened dorsal margin in lateral view. The larger varanodontine varanopids have large transverse processes with a broad base, and a much taller axial spine with a rounded dorsal margin in lateral view. Based on outgroup comparisons, the morphology exhibited by the transverse processes is interpreted as derived in varanodontines, whereas the morphology of the axial spine is derived in mycterosaurines. The axial spine anatomy of Middle Permian South African varanopids is reviewed and our interpretation is consistent with the hypothesis that at least two varanopid taxa are present in South Africa, a region overwhelmingly dominated by therapsid synapsids and parareptiles. Key words: Synapsida, Varanopidae, Mycterosaurinae, Varanodontinae, atlas−axis complex, axial skeleton, Middle Permian, South Africa.
    [Show full text]
  • Phylogeny and Evolution of the Dissorophoid Temnospondyls
    Journal of Paleontology, 93(1), 2019, p. 137–156 Copyright © 2018, The Paleontological Society. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/ licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. 0022-3360/15/0088-0906 doi: 10.1017/jpa.2018.67 The putative lissamphibian stem-group: phylogeny and evolution of the dissorophoid temnospondyls Rainer R. Schoch Staatliches Museum für Naturkunde, Rosenstein 1, D-70191 Stuttgart, Germany 〈[email protected]〉 Abstract.—Dissorophoid temnospondyls are widely considered to have given rise to some or all modern amphibians (Lissamphibia), but their ingroup relationships still bear major unresolved questions. An inclusive phylogenetic ana- lysis of dissorophoids gives new insights into the large-scale topology of relationships. Based on a TNT 1.5 analysis (33 taxa, 108 characters), the enigmatic taxon Perryella is found to nest just outside Dissorophoidea (phylogenetic defintion), but shares a range of synapomorphies with this clade. The dissorophoids proper are found to encompass a first dichotomy between the largely paedomorphic Micromelerpetidae and all other taxa (Xerodromes). Within the latter, there is a basal dichotomy between the large, heavily ossified Olsoniformes (Dissorophidae + Trematopidae) and the small salamander-like Amphibamiformes (new taxon), which include four clades: (1) Micropholidae (Tersomius, Pasawioops, Micropholis); (2) Amphibamidae sensu stricto (Doleserpeton, Amphibamus); (3) Branchiosaur- idae (Branchiosaurus, Apateon, Leptorophus, Schoenfelderpeton); and (4) Lissamphibia. The genera Platyrhinops and Eos- copus are here found to nest at the base of Amphibamiformes. Represented by their basal-most stem-taxa (Triadobatrachus, Karaurus, Eocaecilia), lissamphibians nest with Gerobatrachus rather than Amphibamidae, as repeatedly found by former analyses.
    [Show full text]
  • Physical and Environmental Drivers of Paleozoic Tetrapod Dispersal Across Pangaea
    ARTICLE https://doi.org/10.1038/s41467-018-07623-x OPEN Physical and environmental drivers of Paleozoic tetrapod dispersal across Pangaea Neil Brocklehurst1,2, Emma M. Dunne3, Daniel D. Cashmore3 &Jӧrg Frӧbisch2,4 The Carboniferous and Permian were crucial intervals in the establishment of terrestrial ecosystems, which occurred alongside substantial environmental and climate changes throughout the globe, as well as the final assembly of the supercontinent of Pangaea. The fl 1234567890():,; in uence of these changes on tetrapod biogeography is highly contentious, with some authors suggesting a cosmopolitan fauna resulting from a lack of barriers, and some iden- tifying provincialism. Here we carry out a detailed historical biogeographic analysis of late Paleozoic tetrapods to study the patterns of dispersal and vicariance. A likelihood-based approach to infer ancestral areas is combined with stochastic mapping to assess rates of vicariance and dispersal. Both the late Carboniferous and the end-Guadalupian are char- acterised by a decrease in dispersal and a vicariance peak in amniotes and amphibians. The first of these shifts is attributed to orogenic activity, the second to increasing climate heterogeneity. 1 Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK. 2 Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115 Berlin, Germany. 3 School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK. 4 Institut
    [Show full text]
  • Anatomy and Relationships of the Triassic Temnospondyl Sclerothorax
    Anatomy and relationships of the Triassic temnospondyl Sclerothorax RAINER R. SCHOCH, MICHAEL FASTNACHT, JÜRGEN FICHTER, and THOMAS KELLER Schoch, R.R., Fastnacht, M., Fichter, J., and Keller, T. 2007. Anatomy and relationships of the Triassic temnospondyl Sclerothorax. Acta Palaeontologica Polonica 52 (1): 117–136. Recently, new material of the peculiar tetrapod Sclerothorax hypselonotus from the Middle Buntsandstein (Olenekian) of north−central Germany has emerged that reveals the anatomy of the skull and anterior postcranial skeleton in detail. Despite differences in preservation, all previous plus the new finds of Sclerothorax are identified as belonging to the same taxon. Sclerothorax is characterized by various autapomorphies (subquadrangular skull being widest in snout region, ex− treme height of thoracal neural spines in mid−trunk region, rhomboidal interclavicle longer than skull). Despite its pecu− liar skull roof, the palate and mandible are consistent with those of capitosauroid stereospondyls in the presence of large muscular pockets on the basal plate, a flattened edentulous parasphenoid, a long basicranial suture, a large hamate process in the mandible, and a falciform crest in the occipital part of the cheek. In order to elucidate the phylogenetic position of Sclerothorax, we performed a cladistic analysis of 18 taxa and 70 characters from all parts of the skeleton. According to our results, Sclerothorax is nested well within the higher stereospondyls, forming the sister taxon of capitosauroids. Palaeobiologically, Sclerothorax is interesting for its several characters believed to correlate with a terrestrial life, although this is contrasted by the possession of well−established lateral line sulci. Key words: Sclerothorax, Temnospondyli, Stereospondyli, Buntsandstein, Triassic, Germany.
    [Show full text]
  • Mapping, Stratigraphy, and Tectonic Implications of Lowerrermian
    ...MAPPING, STRATIGRAPHY, AND TECTONIC IMPLICATIONS OF LOWERRERMIAN STRATA, EASTERN ~ICHITA MOUNTAINS, OKLAHOMA By STEVE DWAYNE BRIDGES \\ Bachelor of Science Arkansas Tech University Russellville, Arkansas 1982 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE December, 1985 . ~ T h.ts\.s \tl r 5' ~g S)m car.?- ; . t: .. ' MAPPING, STRATIGRAPHY, AND TECTONIC IMPLICATIONS OF LOWER PERMI-AN STRATA, EASTERN WICHITA MOUNTAINS, OKLAHOMA Thesis Approved: Thesis Adviser ,/JrdL'VV\ Ce~ ean of the Graduate College ii 1236335 PREFACE The purpose of this thesis is to map, propose a revised stratigraphic section for, and comment on the tectonic implications of the Lower Permian deposits surrounding the eastern Wichita Mountains of southwestern Oklahoma. It is hoped that this thesis will raise questions and encourage investigators to scrutinize the geologic literature so that our geologic interpretations can continue to evolve. I am deeply indebted to the many individuals that provided useful comments, ideas, and suggestions which helped in the completion of this study. Deepest appreciations are conveyed to my major advisor Dr. R. Nowell Donovan for his counsel, guidance and friendship and to my committee members Dr. Gary F. Stewart and Dr. Ibrahim Cemen for their suggestions and review of the text. Sincere thanks are expressed to Deborah Ragland who ordered photos and provided interpretations which were vital in the preparation of this thesis. Gratitude is expressed to Mr. and Mrs. Charlie Oliver for their hospitality, friendship and for allowing me the "run" of the Kimbell Ranch.
    [Show full text]