DOCSLIB.ORG

30-Johnson (Xenacanth)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Lucas, S.G., et al. eds., 2013, The Carboniferous-Permian Transition. New Mexico Museum of Natural History and Science, Bulletin 60. 161 XENACANTH SHARKS AND OTHER VERTEBRATES FROM THE GERALDINE BONEBED, LOWER PERMIAN OF TEXAS GARY D. JOHNSON Shuler Museum of Paleontology, Institute for the Study of Earth and Man, Southern Methodist University, PO Box 750274, Dallas, Texas 75275-0274; email: [email protected] Abstract—The Geraldine Bonebed occurs in the Nocona Formation (Wichita Group, Sakmarian age) in Texas. It has historically yielded a large number of mostly complete skeletons of four tetrapod taxa, for which it is famous, and also a diverse flora as well as other vertebrates. Bulk samples of matrix were recently screen-washed and sorted to produce a variety of vertebrate microfossils, including sharks, especially xenacanths. The non-xenacanth sharks are rare and include a petalodont tooth (Janassa?), Helodus sp. (4 teeth) and one partial hybodont tooth. These are all considerably more common higher in the Wichita Group. Only the petalodont and possibly the hybodont and Helodus represent a marine component in the fauna, but the marine faunas are more extensive higher in the Wichita. Also new to the fauna are acanthodians, actinopterygians, Cardiocephalus and Ophiacodon. Among the xenacanths are two typically small Xenacanthus sp. occipital spine fragments, two Orthacanthus sp. occipital spine frag- ments (one small, one very small) and hundreds of Orthacanthus teeth. Orthacanthus texensis teeth are much more common than O. platypternus teeth. Teeth of O. texensis and O. platypternus are comparable in size distributions, as determined by statistical analyses of the tooth-base measurements, to those higher in the Wichita Group. With one possible exception (the exact locality cannot be confirmed), O. texensis and O. platypternus are not known to occur below the Nocona Formation in Texas, nor are they anywhere older than Sakmarian age. INTRODUCTION Group) in central Archer County (Fig. 2) and recognized four types of The purpose of this study is to add additional taxa to the previ- associated deposits. One of these, a catastrophic event bonebed, is rep- ously known fauna of the Geraldine Bonebed with emphasis on the resented by the Geraldine Bonebed, but Sander’s (1989) primary intent xenacanth sharks, obtained by bulk processing of matrix to yield a verte- was to describe four occurrences of floodplain pond bonebeds. All four brate microfossil component (Johnson et al., 1994). This bonebed, dis- of these probably contain a more diversified vertebrate fauna than does covered by A. S. Romer in 1932 in central Archer County, probably the Geraldine Bonebed (three of the faunal lists were updated by Johnson, represents the most prolific source of articulated tetrapod skeletons in 2007, 2012). The other two types of deposits recognized by Sander the Lower Permian of North America (Sander, 1987). These include 11 (1989) are isolated skeletons and lag bonebeds. mostly articulated skeletons of Archeria crassidisca, an embolomerous In his description of the pond bonebeds, Sander (1989) did not amphibian; 15 or more associated or articulated skeletons of the laby- recognize any evidence of marine incursions. Hentz (1988, figs. 11-12) rinthodont amphibian Eryops megacephalus; 14 or more partial to com- presented a broad overview of the paleogeography of north-central Texas plete skeletons of the herbivorous synapsid Edaphosaurus boanerges; during the time of deposition of the Archer City Formation (Asselian and three associated skeletons of a carnivorous synapsid, Dimetrodon age). Based on this, Sander’s (1989) pond bonebeds occurred in the natalis. Sander (1987) provided a history of collecting these specimens upper part of a lower coastal plain. This could reasonably explain the together with pertinent associated details. He also provided a detailed presence of marine taxa in these bonebeds under varying circumstances, study of the sedimentology, flora (some two dozen taxa) and taphonomy although their occurrence in the Geraldine Bonebed is more problematic. of the bonebed. It is of Sakmarian (Wolfcampian) age and occurs in the GERALDINE BONEBED VERTEBRATE FAUNA Nocona Formation, Wichita Group (Figs. 1-2). Sander (1987) noted the low diversity of the vertebrate fauna with only three amphibian taxa Taxa in addition to those listed by Sander (1987, table II), includ- (including Diadectes sp.) and three amniote taxa (including Bolosaurus ing indeterminate partial bones and teeth plus tooth and bone fragments striatus) from the bonebed proper, plus two more amphibians that were obtained by bulk processing of matrix from the bonebed, are (Trimerorachis insignis and Zatrachys sp.) and one additional synapsid cataloged as SMU 76693-76753 (Shuler Museum of Paleontology, South- (Ophiacodon uniformis) from the same vicinity. Among the fishes, only ern Methodist University Locality 161). Additional surface-collected one shark (Orthacanthus texensis) and one crossopterygian fossils (SMU 69461-69472, 69499) did not add any taxa to those listed (Ectosteorachis nitidus) were recorded from the bonebed, plus one lung- by Sander (1987). The screen-washed bulk samples (two sites several fish (Sagenodus sp.) from nearby. meters apart within the bonebed) produced the following taxa (catalog Sander (1987) concluded that the Geraldine Bonebed and related numbers in parentheses; the xenacanths are treated separately below; sediments and flora constituted a floodbasin of a small meandering river * taxa not listed in the bonebed proper by Sander, 1987): system. The vertebrate-bearing facies contain only a minor fine-grained sandstone with ripple bedding in what otherwise is mudstone (Sander, Class Chondrichthyes 1987, fig. 3), which he interpreted to represent a freshwater pond in an Subclass Elasmobranchii overall swamp environment. Although he presumed the presence of ox- *hybodontid indet. (partial tooth, 76713) bow lakes in the region, he did not specify such an occurrence for the Orthacanthus texensis bonebed, presumably because of the geometry of the facies distribution. *O. platypternus Sander (1989) provided an analysis of the sedimentology of a portion of *Xenacanthus sp. the Nocona Formation and subjacent Archer City Formation (Bowie Subclass Holocephali *Helodus sp. (4 teeth, 76714) 162 FIGURE 1. Stratigraphic section of western North-Central Texas; from Johnson (2011), based on Hentz and Brown (1987). Abbreviations: Pcj, Coleman Junction Formation; Psb, Santa Ana Branch Shale; Pse, Sedwick Formation; Pmo, Moran Formation; Ppb, Pueblo Formation; lPP, Pennsylvanian- Permian; lPPh, Harpersville Formation. 163 Subclass Incertae Sedis In addition, there are a variety of fish teeth including *Janassa? (single incomplete petalodont tooth, actinopterygians (SMU 76621, 76723, 76724), amphibian teeth (76732) 76717) and a reptile caudal? vertebra (76737) and claw (76738). Three small Class Incertae Sedis Acanthodii coprolites (76739) are present; the smallest (6 mm) has a spiral structure *Acanthodes sp. (partial fin spines and scales, not and the other two contain palaeoniscoid scales. A variety of partial bones, common, 76715, 76716) isolated teeth and fragments are present (76740-76745), some of which Class Osteichthyes are probably identifiable. Subclass Actinopterygii *palaeoniscids indet. (scales and teeth common, XENACANTH SHARKS IN THE GERALDINE BONEBED 76718, 76719) Three species of xenacanths (Xenacanthiformes Berg, 1937, 1940; *Platysomus? (single “button tooth,” 76720; see Xenacanthodii Olson, 1946?; Xenacanthida Glikman, 1964) occur in the Johnson and Zidek, 1981) bonebed. Orthacanthus texensis is represented by teeth (SMU 76693- Subclass Sarcopterygii 76702) as is O. platypternus (SMU 76703-76707). Two Orthacanthus crossopterygian indet. (skull fragments, scales sp. small to very small occipital spine fragments (SMU 76709) were common, 76722) recovered. Also, two small spine fragments of Xenacanthus sp. (SMU Sagenodus sp. (5 partial tooth plates, 76725) 76710) occur in the fauna, but Xenacanthus teeth were not recovered, Class Amphibia similar to the faunas in the Archer City Bonebed 3 and Conner Ranch Order Temnospondyli Bonebed (Fig. 2; Johnson, 2012). Xenacanths are also represented by Trimerorhachis sp. (teeth and partial jaws denticles and prismatic cartilage (SMU 76711, 76712). uncommon, 76729) Orthacanthus texensis teeth are very common (total of 1808) in Eryops sp. (skull and jaw fragments common, 76728) the Geraldine fauna. Besides normal teeth, 13 teeth are germinal (under- Order Anthracosauria developed; Johnson, 2005) and three are deformed (Johnson, 1987) (SMU Archeria sp. (6 vertebrae, 76726) 76697, 76698). Of the remaining teeth, 141 were measured (Fig. 3A). A Order Microsauria statistical analysis is summarized in Table 1. The anteromedial-postero- *Cardiocephalus sp. (3 teeth, 76731) lateral (length of tooth base) dimension is taken as the independent Class Reptilia variable because it is usually easier to measure in Orthacanthus teeth. Order Parareptilia The measured population may be skewed toward the lower range (Fig. Bolosaurus sp. (14 teeth, partial jaw, 76730) 3A) because nearly all of the larger teeth were probably removed by Class Synapsida earlier surface collecting. Forty-nine teeth were surface-collected (SMU *Ophiacodon sp. (teeth common, 76735) 69461), but they are incomplete with some badly worn or weathered. Dimetrodon sp. (neural spine fragments and teeth Sander (1987, p. 228) noted that the teeth are smaller
Recommended publications
  • A Late Permian Ichthyofauna from the Zechstein Basin, Lithuania-Latvia Region

    A Late Permian Ichthyofauna from the Zechstein Basin, Lithuania-Latvia Region

    bioRxiv preprint doi: https://doi.org/10.1101/554998; this version posted February 20, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. 1 A late Permian ichthyofauna from the Zechstein Basin, Lithuania-Latvia Region 2 3 Darja Dankina-Beyer1*, Andrej Spiridonov1,4, Ģirts Stinkulis2, Esther Manzanares3, 4 Sigitas Radzevičius1 5 6 1 Department of Geology and Mineralogy, Vilnius University, Vilnius, Lithuania 7 2 Chairman of Bedrock Geology, Faculty of Geography and Earth Sciences, University 8 of Latvia, Riga, Latvia 9 3 Department of Botany and Geology, University of Valencia, Valencia, Spain 10 4 Laboratory of Bedrock Geology, Nature Research Centre, Vilnius, Lithuania 11 12 *[email protected] (DD-B) 13 14 Abstract 15 The late Permian is a transformative time, which ended in one of the most 16 significant extinction events in Earth’s history. Fish assemblages are a major 17 component of marine foods webs. The macroevolution and biogeographic patterns of 18 late Permian fish are currently insufficiently known. In this contribution, the late Permian 19 fish fauna from Kūmas quarry (southern Latvia) is described for the first time. As a 20 result, the studied late Permian Latvian assemblage consisted of isolated 21 chondrichthyan teeth of Helodus sp., ?Acrodus sp., ?Omanoselache sp. and 22 euselachian type dermal denticles as well as many osteichthyan scales of the 23 Haplolepidae and Elonichthydae; numerous teeth of Palaeoniscus, rare teeth findings of 1 bioRxiv preprint doi: https://doi.org/10.1101/554998; this version posted February 20, 2019.
  • Geological Survey of Ohio

    Geological Survey of Ohio

    GEOLOGICAL SURVEY OF OHIO. VOL. I.—PART II. PALÆONTOLOGY. SECTION II. DESCRIPTIONS OF FOSSIL FISHES. BY J. S. NEWBERRY. Digital version copyrighted ©2012 by Don Chesnut. THE CLASSIFICATION AND GEOLOGICAL DISTRIBUTION OF OUR FOSSIL FISHES. So little is generally known in regard to American fossil fishes, that I have thought the notes which I now give upon some of them would be more interesting and intelligible if those into whose hands they will fall could have a more comprehensive view of this branch of palæontology than they afford. I shall therefore preface the descriptions which follow with a few words on the geological distribution of our Palæozoic fishes, and on the relations which they sustain to fossil forms found in other countries, and to living fishes. This seems the more necessary, as no summary of what is known of our fossil fishes has ever been given, and the literature of the subject is so scattered through scientific journals and the proceedings of learned societies, as to be practically inaccessible to most of those who will be readers of this report. I. THE ZOOLOGICAL RELATIONS OF OUR FOSSIL FISHES. To the common observer, the class of Fishes seems to be well defined and quite distin ct from all the other groups o f vertebrate animals; but the comparative anatomist finds in certain unusual and aberrant forms peculiarities of structure which link the Fishes to the Invertebrates below and Amphibians above, in such a way as to render it difficult, if not impossible, to draw the lines sharply between these great groups.
  • A Juvenile Skeleton of the Nectridean Amphibian

    A Juvenile Skeleton of the Nectridean Amphibian

    Lucas, S.G. and Zeigler, K.E., eds., 2005, The Nonmarine Permian, New Mexico Museum of Natural Histoiy and Science Bulletin No. 30. 39 A JUVENILE SKELETON OF THE NECTRIDEAN AMPHIBIAN DIPLOCAULUS AND ASSOCIATED FLORA AND FAUNA FROM THE MITCHELL CREEK FLATS LOCALITY (UPPER WAGGONER RANCH FORMATION; EARLY PERMIAN), BAYLOR COUNTY, NORTH- CENTRAL TEXAS, USA DAN S. CHANEY, HANS-DIETER SUES AND WILLIAM A. DIMICHELE Department of Paleobiology MRC-121, National Museum of Natural History, PC Box 37012, Washington, D.C. 20013-7021 Abstract—A well-preserved skeleton of a tiny individual of the nectridean amphibian Diplocaulus was found in association with other Early Permian animal remains and a flora in a gray mudstone at a site called Mitchell Creek Flats in Baylor County, north-central Texas. The locality has the sedimentological attributes of a pond deposit. The skeleton of Diplocaulus sp. is noteworthy for its completeness and small size, and appears to represent a juvenile individual. The associated plant material is beautifully preserved and comprises the sphe- nopsids Annularia and Calamites, the conifer IBrachyphyllum, possible cycads represented by one or possibly two forms of Taeniopteris, three gigantopterids - Delnortea, Cathaysiopteris, and Gigantopteridium — and three unidentified callipterids. Several unidentified narrow trunks were found at the base of the deposit, appar- ently washed up against the northern margin of the pond. Other faunal material from the deposit comprises myalinid bivalves, conchostracans, a tooth of a xenacanthid shark, and a palaeonisciform fish. INTRODUCTION Wchita Rver T ^ Coinage i ^ 1 t Complete skeletons of Early Permian vertebrates are rare in north- FwmatJon Grcyp c central Texas, where much collecting has been done for about 150 years c c (Fig.
  • New England Zoological Club

    New England Zoological Club

    PROCEEDINGS OF THE NEW ENGLAND ZOOLOGICAL CLUB NEW GENERA AND SPECIES OF PELYCOSAURIAN REPTILES BY ALFRED SHERWOOD ROMER IN the course of recent collecting trips by the Museum of Comparative Zoology and a re-study of pre-existing collections, Ii number of new types of Permo-Carboniferous pelycosaurs have come to light. I hope to discuss these reptiles in a general review of the group, which is approaching completion. This $tudy has been aided by a grant from the Penrose Fund of the Geological Society of America, and the present preliminary cliagnoses of the new types are published with the permission or the Society. Eothyris parkeyi gen. et spec. nov. Genoholotype, M.C.Z., 1161, (figured): a skull and jaws, found about one mile west of the former Woodrum ranch-house, $outh of Dundee, Archer County, Texas; horizon Belle Plains P.N.E.Z.C. ROMER--PELYCOSAURS [ pooember30] 90 Vol. XVI 1937 ROMER--PELYCOSA Formation, Wichita Group. A small primitive pelycosaur, the type skull about 65 mm. in length as preserved. The skull Lupeosaurus kayi gen. et sp' is relatively broad and low, and the face short, (although this appearance is increased by distortion and damage in the type); Genoholotype, M.C.Z., 1455, a preS8 the orbit and temporal region are relatively elongated. The and scapulocoracoid, found near the postorbital has a broad posterior expansion above the small Creek, Archer County, Texas; horizOI temporal vacuity. The parietal is very primitive, in extend­ Formation, Wichita Group. A pelycos ing far back of the pineal. The supra-temporal is relatively sembling Edaphosaurus in caudal verter large.
  • Xenacanthus (Chondrichthyes: Xenacanthiformes) from North America

    Xenacanthus (Chondrichthyes: Xenacanthiformes) from North America

    Acta Geologica Polonica, Vol. 49 (J 999), No.3, pp. 215-266 406 IU S UNES 0 I Dentitions of Late Palaeozoic Orthacanthus species and new species of ?Xenacanthus (Chondrichthyes: Xenacanthiformes) from North America GARY D. JOHNSON Department of Earth Sciences and Physics, University of South Dakota; 414 East Clark Street, Vermillion, SD 57069-2390, USA. E-mail: [email protected] ABSTRACT: JOHNSON, G.D. 1999. Dentitions of Late Palaeozoic Orthacanthus species and new species of ?Xenacanthus (Chondrichthyes: Xenacanthiformes) from North America. Acta Geologica Polonica, 49 (3),215-266. Warszawa. Orthacanthus lateral teeth have paired, variably divergent, smooth, usually carinated labio-lingually compressed principal cusps separated by a central foramen; one or more intermediate cusps; and an api­ cal button on the base isolated from the cusps. Several thousand isolated teeth from Texas Artinskian bulk samples are used to define the heterodont dentitions of O. texensis and O. platypternus. The O. tex­ ensis tooth base has a labio-Iingual width greater than the anteromedial-posterolateral length, the basal tubercle is restricted to the thick labial margin, the principal cusps are serrated to varying degrees, and the posterior cusp is larger. The O. platypternus tooth base is longer than wide, its basal tubercle extends to the center, the labial margin is thin, serrations are absent on the principal cusps, the anterior cusp is larger, and a single intermediate cusp is present. More than two hundred isolated teeth from Nebraska (Gzhelian) and Pennsylvania (Asselian) provide a preliminary description of the heterodont dentition of O. compress us . The principal cusps are similar to O.
  • Late Devonian and Early Carboniferous Chondrichthyans from the Fairfield Group, Canning Basin, Western Australia

    Late Devonian and Early Carboniferous Chondrichthyans from the Fairfield Group, Canning Basin, Western Australia

    Palaeontologia Electronica palaeo-electronica.org Late Devonian and Early Carboniferous chondrichthyans from the Fairfield Group, Canning Basin, Western Australia Brett Roelofs, Milo Barham, Arthur J. Mory, and Kate Trinajstic ABSTRACT Teeth from 18 shark taxa are described from Upper Devonian to Lower Carbonif- erous strata of the Lennard Shelf, Canning Basin, Western Australia. Spot samples from shoal facies in the upper Famennian Gumhole Formation and shallow water car- bonate platform facies in the Tournaisian Laurel Formation yielded a chondrichthyan fauna including several known species, in particular Thrinacodus ferox, Cladodus thomasi, Protacrodus aequalis and Deihim mansureae. In addition, protacrodont teeth were recovered that resemble formally described, yet unnamed, teeth from Tournaisian deposits in North Gondwanan terranes. The close faunal relationships previously seen for Late Devonian chondrichthyan taxa in the Canning Basin and the margins of north- ern Gondwana are shown here to continue into the Carboniferous. However, a reduc- tion in species overlap for Tournaisian shallow water microvertebrate faunas between the Canning Basin and South China is evident, which supports previous studies docu- menting a separation of faunal and terrestrial plant communities between these regions by this time. The chondrichthyan fauna described herein is dominated by crushing type teeth similar to the shallow water chondrichthyan biofacies established for the Famennian and suggests some of these biofacies also extended into the Early Carboniferous. Brett Roelofs. Department of Applied Geology, Curtin University, GPO Box U1987 Perth, WA 6845, Australia. [email protected] Milo Barham. Department of Applied Geology, Curtin University, GPO Box U1987 Perth, WA 6845, Australia. [email protected] Arthur J.
  • Geology of the Cross Plains Quadrangle, Brown, Callahan Coleman, and Eastland Counties Texas

    Geology of the Cross Plains Quadrangle, Brown, Callahan Coleman, and Eastland Counties Texas

    Geology of the Cross Plains Quadrangle, Brown, Callahan Coleman, and Eastland Counties Texas GEOLOGICAL SURVEY BULLETIN 1096-B Prepared in cooperation with the Bureau of Economic Geology, The University of Texas Geology of the Cross Plains Quadrangle, Brown, Callahan Coleman, and Eastland Counties Texas By PHILIP T. STAFFORD PENNSYLVANIAN AND LOWER PERMIAN STRATIG­ RAPHY, BETWEEN THE BRAZOS AND COLORADO RIVERS, NORTH-CENTRAL TEXAS GEOLOGICAL SURVEY BULLETIN 1096-B Prepared in cooperation with the Bureau of Economic Geology, The University of Texas UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1960 UNITED STATES DEPARTMENT OF THE INTERIOR FRED A. SEATON, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.G. CONTENTS Page Abstract___ _____________________________________________________ 39 Introduction._____________________________________________________ 40 Location of area_______________________________________________ 40 Purpose ______________________________________________________ 40 Previous geologic studies. ______________________________________ 40 Acknowledgments _____________________________________________ 41 Methods of study____________________________________________ 42 Mapping and fieldwork___________________________________ 42 Descriptive terminology.__-____________-_____-___-_-_-_-___ 43 Stratigraphy. _____________________________________________________ 44 Pennsylvanian and Permian systems.____________________________
  • Copyrighted Material

    Copyrighted Material

    06_250317 part1-3.qxd 12/13/05 7:32 PM Page 15 Phylum Chordata Chordates are placed in the superphylum Deuterostomia. The possible rela- tionships of the chordates and deuterostomes to other metazoans are dis- cussed in Halanych (2004). He restricts the taxon of deuterostomes to the chordates and their proposed immediate sister group, a taxon comprising the hemichordates, echinoderms, and the wormlike Xenoturbella. The phylum Chordata has been used by most recent workers to encompass members of the subphyla Urochordata (tunicates or sea-squirts), Cephalochordata (lancelets), and Craniata (fishes, amphibians, reptiles, birds, and mammals). The Cephalochordata and Craniata form a mono- phyletic group (e.g., Cameron et al., 2000; Halanych, 2004). Much disagree- ment exists concerning the interrelationships and classification of the Chordata, and the inclusion of the urochordates as sister to the cephalochor- dates and craniates is not as broadly held as the sister-group relationship of cephalochordates and craniates (Halanych, 2004). Many excitingCOPYRIGHTED fossil finds in recent years MATERIAL reveal what the first fishes may have looked like, and these finds push the fossil record of fishes back into the early Cambrian, far further back than previously known. There is still much difference of opinion on the phylogenetic position of these new Cambrian species, and many new discoveries and changes in early fish systematics may be expected over the next decade. As noted by Halanych (2004), D.-G. (D.) Shu and collaborators have discovered fossil ascidians (e.g., Cheungkongella), cephalochordate-like yunnanozoans (Haikouella and Yunnanozoon), and jaw- less craniates (Myllokunmingia, and its junior synonym Haikouichthys) over the 15 06_250317 part1-3.qxd 12/13/05 7:32 PM Page 16 16 Fishes of the World last few years that push the origins of these three major taxa at least into the Lower Cambrian (approximately 530–540 million years ago).
  • A New Cochliodont Anterior Tooth Plate from the Mississippian of Alabama (USA) Having Implications for the Origin of Tooth Plates from Tooth Files Wayne M

    A New Cochliodont Anterior Tooth Plate from the Mississippian of Alabama (USA) Having Implications for the Origin of Tooth Plates from Tooth Files Wayne M

    Itano and Lambert Zoological Letters (2018) 4:12 https://doi.org/10.1186/s40851-018-0097-8 RESEARCHARTICLE Open Access A new cochliodont anterior tooth plate from the Mississippian of Alabama (USA) having implications for the origin of tooth plates from tooth files Wayne M. Itano1* and Lance L. Lambert2 Abstract Background: Paleozoic holocephalian tooth plates are rarely found articulated in their original positions. When they are found isolated, it is difficult to associate the small, anterior tooth plates with the larger, more posterior ones. Tooth plates are presumed to have evolved from fusion of tooth files. However, there is little fossil evidence for this hypothesis. Results: We report a tooth plate having nearly perfect bilateral symmetry from the Mississippian (Chesterian Stage) Bangor Limestone of Franklin County, Alabama, USA. The high degree of symmetry suggests that it may have occupied a symphyseal or parasymphyseal position. The tooth plate resembles Deltodopsis? bialveatus St. John and Worthen, 1883, but differs in having a sharp ridge with multiple cusps arranged along the occlusal surface of the presumed labiolingual axis, rather than a relatively smooth occlusal surface. The multicusped shape is suggestive of a fused tooth file. The middle to latest Chesterian (Serpukhovian) age is determined by conodonts found in the same bed. Conclusion: The new tooth plate is interpreted as an anterior tooth plate of a chondrichthyan fish. It is referred to Arcuodus multicuspidatus Itano and Lambert, gen. et sp. nov. Deltodopsis? bialveatus is also referred to Arcuodus. Keywords: Chondrichthyes, Cochliodontiformes, Carboniferous, Mississippian, Bangor limestone, Alabama, Conodonts Background Paleontological studies show that the elasmobranch dental Extant chondrichthyan fishes comprise two clades: the pattern of rows of tooth files, with teeth replaced in a elasmobranchs (sharks, skates, and rays) and the holoce- linguo-labial sequence has been highly conserved, since it phalians (chimaeras).
  • The Yellowstone Paleontological Survey

    The Yellowstone Paleontological Survey

    E PALEONT ON O T LO S G W I O C L A L L E National Y Park The Yellowstone Service Department of the Interior Paleontological Survey SURVEY Vincent L. Santucci Yellowstone Center for Resources National Park Service Yellowstone National Park, Wyoming YCR-NR-98-1 1998 How to cite this document: Santucci, V. L. 1998. The Yellowstone Paleontological Survey. Yellowstone Center for Resources, National Park Service, Yellowstone National Park, Wyoming,YCR-NR-98-1. Current address for Vincent L. Santucci is National Park Service, P.O. Box 592, Kemmerer, WY 83101. The Yellowstone Paleontological Survey To Lt. Col. Luke J. Barnett, III “Uncle by blood, brother in spirit!” Vincent L. Santucci Yellowstone Center for Resources National Park Service Yellowstone National Park, Wyoming YCR-NR-98-1 1998 Table of Contents Introduction .................................................................................................... 1 Stratigraphy .................................................................................................... 4 Fossil Chronology........................................................................................... 6 Taxonomy ..................................................................................................... 12 Localities ...................................................................................................... 15 Interpretation ................................................................................................ 19 Paleontological Resource Management.......................................................
  • Occurrence, Availability, and Chemical Quality of Ground

    Occurrence, Availability, and Chemical Quality of Ground

    TEXAS DEPARTMENT OF WATER RESOURCES REPORT 269 OCCURRENCE, AVAILABILITY, AND CHEMICAL QUALITY OF GROUND WATER IN THE CRETACEOUS AQUIFERS OF NORTH-CENTRAL TEXAS VOLUME 1 Phillip L. Nordstrom, Geologist April 1982 TEXAS DEPARTMENT OF WATER RESOURCES Harvey Davis, Executive Director TEXAS WATER DEVELOPMENT BOARD Louis A. Beecherl Jr., Chairman John H. Garrett, Vice Chairman George W. McCleskey W. 0. Bankston Glen E. Roney Lonnie A. “Bo” Pilgrim TEXAS WATER COMMISSION Felix McDonald, Chairman Dorsey B. Hardeman, Commissioner Lee B. M. Biggart, Commissioner Authorization for use or reproduction of any original material contained in this publication, i.e., not obtained from other sources, is freely granted. The Department would appreciate acknowledgement. Published and distributed by the Texas Department of Water Resources Post Office Box 13087 Austin, Texas 78711 ii __ TABLE OF CONTENTS Page SUMMARY AND CONCLUSIONS . 1 INTRODUCTION . .. 3 Purpose and Scope . 3 Location and Extent . 3 Physiography . 3 Climate . 4 Population . 4 Economy . 4 Previous Investigations . 4 Acknowledgements . 7 Method of Investigation . 7 Well-Numbering System . 7 Metric Conversion . 8 GEOLOGY AS RELATED TO THE OCCURRENCE OF GROUND WATER . 9 Geologic History . 9 Paleozoic . 9 Cretaceous . 9 Tertiary and Quaternary . 9 General Stratigraphy . 9 Structure . 10 STRATIGRAPHY OF THE WATER-BEARING FORMATIONS . 12 Paleozoic Rocks . 12 Antlers . 13 iii TABLE OF CONTENTS – Continued Page Twin Mountain Formation . 13 Paluxy Formation . 14 Woodbine Group . 14 Blossom Sand . 15 Nacatoch Sand . 15 CHEMICAL QUALITY OF GROUND WATER AS RELATED TO USE . 15 General Chemical Quality of Ground Water . 15 Quality Criteria or Standards . 16 Municipal . 16 Primary Standards . 20 Secondary Standards .
  • Morphology and Histology of Dorsal Spines of the Xenacanthid Shark

    Morphology and Histology of Dorsal Spines of the Xenacanthid Shark

    Morphology and histology of dorsal spines of the xenacanthid shark Orthacanthus platypternus from the Lower Permian of Texas, USA: Palaeobiological and palaeoenvironmental implications KIMBERLY G. BECK, RODRIGO SOLER-GIJÓN, JESSE R. CARLUCCI, and RAY E. WILLIS Beck, K.G., Soler-Gijón, R., Carlucci, J.R., and Willis, R.E. 2016. Morphology and histology of dorsal spines of the xenacanthid shark Orthacanthus platypternus from the Lower Permian of Texas, USA: Palaeobiological and palaeoen- vironmental implications. Acta Palaeontologica Polonica 61 (1): 97–117. Detailed studies on Carboniferous species of the xenacanth Orthacanthus have shown that the xenacanth dorsal fin spine can be used for skeletochronological analyses and provides valuable information about development, growth and environmental life conditions of those extinct sharks. We report here for the first time the histology and skeletochro- nology of Permian specimens, dorsal spines of Orthacanthus platypternus from the Craddock Bone Bed (lower Clear Fork Formation; Early Permian, Leonardian age) of northern Baylor County (north-central Texas, USA). Twelve dorsal spines of O. platypternus preserve a highly vascularized wall mainly composed of centrifugally growing dentine in a succession of dentine layers, probably deposited with an annual periodicity. As expected, spines of individuals with 1–2 dentine layers, presumably juveniles, present the smallest sizes. However, spines of individuals showing at least 3–4 dentine layers and interpreted to be subadults/young adults, are distributed in two spine-size clusters corresponding to females (probably the largest spines) and males, in agreement with the hypothesis of sexual size dimorphism proposed in a previous biometric analysis. Our comparative study of O. platypternus and the Stephanian species O.