scholarly journals Exceptionally preserved conodont apparatuses with giant elements from the Middle Ordovician Winneshiek Konservat-Lagerstätte, Iowa, USA

2017 ◽  
Vol 91 (3) ◽  
pp. 493-511 ◽  
Author(s):  
Huaibao P. Liu ◽  
Stig M. Bergström ◽  
Brian J. Witzke ◽  
Derek E. G. Briggs ◽  
Robert M. McKay ◽  
...  

AbstractConsiderable numbers of exceptionally preserved conodont apparatuses with hyaline elements are present in the middle-upper Darriwilian (Middle Ordovician, Whiterockian) Winneshiek Konservat-Lagerstätte in northeastern Iowa. These fossils, which are associated with a restricted biota including other conodonts, occur in fine-grained clastic sediments deposited in a meteorite impact crater. Among these conodont apparatuses, the common ones are identified asArcheognathus primusCullison, 1938 andIowagnathus grandisnew genus new species. The 6-element apparatus ofA.primuscomprises two pairs of archeognathiform (P) and one pair of coleodiform (S) elements. The 15-element apparatus ofI.grandisn. gen. n. sp. is somewhat reminiscent of the prioniodinid type and contains ramiform elements of alate (one element) and digyrate, bipennate, or tertiopedate types (7 pairs). Both conodont taxa are characterized by giant elements and the preservation of both crowns and basal bodies, the latter not previously reported in Ordovician conodont apparatuses. Comparison of the apparatus size in the Winneshiek specimens with that of the Scottish Carboniferous soft-part-preserved conodont animals suggests that the Iowa animals were significantly larger than the latter. The apparatus ofA.primusdiffers conspicuously from the apparatuses of the prioniodontidPromissumfrom the Upper Ordovician Soom Shale of South Africa although the apparatus architecture ofI.grandisn. gen. n. sp. shows some similarity to it. Based on the Winneshiek collections, a new family Iowagnathidae in Conodonta is proposed.

2007 ◽  
Vol 44 (10) ◽  
pp. 1479-1501 ◽  
Author(s):  
John Pojeta Jr. ◽  
Christopher A Stott

The new Ordovician palaeotaxodont family Nucularcidae and the new genus Nucularca are described. Included in Nucularca are four previously described species that have taxodont dentition: N. cingulata (Ulrich) (the type species), N. pectunculoides (Hall), N. lorrainensis (Foerste), and N. gorensis (Foerste). All four species are of Late Ordovician (Cincinnatian Katian) age and occur in eastern Canada and the northeastern USA. Ctenodonta borealis Foerste is regarded as a subjective synonym of Nucularca lorrainensis. No new species names are proposed. The Nucularcidae includes the genera Nucularca and Sthenodonta Pojeta and Gilbert-Tomlinson (1977). Sthenodonta occurs in central Australia in rocks of Middle Ordovician (Darriwilian) age. The 12 family group names previously proposed for Ordovician palaeotaxodonts having taxodont dentition are reviewed and evaluated in the Appendix.


2007 ◽  
Vol 81 (6) ◽  
pp. 1442-1453 ◽  
Author(s):  
María José Salas

Ostracod faunas from the Lower to Middle Ordovician rocks of the Argentine Precordillera Basin (Gualcamayo and Las Aguaditas Formations) are studied. A new family, Garcianidae, is erected. One new genus,Jeanvannieria, and six species are recognized, two of which are new (Jachalipisthia bicornataandJeanvannieria bulbosa). The diversity and composition of the Precordilleran ostracods is evaluated on the basis of previous taxonomic analysis and the fauna studied here. The diversity is moderate, with a peak of 50 species during the early Caradoc. The composition of the fauna is characterized by the dominance of podocopes with a high percentage of binodicopes and a lack of palaeocopes, which is in agreement with a deep shelf environment. The carbonate slope setting of the Las Aguaditas Formation is the deepest environment yet found with Ordovician ostracods and records a relatively diverse fauna. The presence ofEctoprimitioidessuggests biogeographic affinities between the Precordillera and Laurentia. The rest of the fauna contains a high percentage of endemic genera and a mixture of genera with several affinities, Baltic, peri-Gondwanan, and Australian.


This communication contains a description of species belonging to two genera of Echinoidea from the Upper Ordovician (Ashgillian) of Girvan, Scotland, namely, Aulechinus Bather and Spencer, and Ectinechinus n.g., together with a description of a new genus Eothuria , regarded as the first known holothurid, from the same locality. Some notes are added on the Middle Ordovician echinoid Myriastiches and the Silurian genera Palaeodiscus and Echinocystis . A short note upon one of the Ordovician genera, Aulechinus , was communicated by Spencer to the Annals and Magazine of Natural History , immediately after the death of Dr Bather. It contained facts which had been agreed upon by Dr Bather and Spencer, whilst working together. Dr Mortensen was anxious to include some account of the material in his new monograph, and the note was published to help him. At that time only fragments of the forms were known.


1984 ◽  
Vol 21 (12) ◽  
pp. 1349-1367 ◽  
Author(s):  
S. P. Colman-Sadd ◽  
H. S. Swinden

In the Through Hill area of central Newfoundland, mafic to ultramafic complexes, which preserve varying amounts of ophiolite stratigraphy, mark the trace of a major fault zone that outcrops in a roughly elliptical pattern. The major, northeast-trending axis is about 60 km and the shorter axis is about 30 km in length. The most complete ophiolite stratigraphy is preserved in the Coy Pond and Pipestone Pond complexes, which have steep dips and face east and west, respectively, outwards from the centre of the ellipse.The ophiolitic rocks are bounded on the outside by rocks typical of the Dunnage Zone of central Newfoundland, principally Lower to Middle Ordovician volcanic and volcaniclastic rocks interpreted to be of island-arc affinity (Davidsville, Victoria Lake, and Baie d'Espoir groups, Cold Spring Pond Formation) and Upper Ordovician to Silurian clastic sediments (Botwood Group). The volcano-sedimentary sequences are interpreted to have been deposited on the ophiolite conformably, but the contacts are not exposed. Both ophiolite and volcano-sedimentary sequences have similar structural and metamorphic histories, exhibiting one principal deformation and the formation of folds with subhorizontal axes, local development of second-generation folds and associated cleavage, and an intervening period of metamorphism in the greenschist facies.The elliptical area enclosed by the ophiolite belt is referred to as the Mount Cormack Terrane, and is underlain by variably metamorphosed shale, quartz-rich sandstone, quartzo-feldspathic to amphibolitic gneisses, and granite. A limestone occurrence contains shelly fossils of Early to Middle Ordovician age. An early deformation formed folds with steep axes, and subsequent metamorphism resulted in a progression from greenschist facies to upper amphibolite facies, with the production of migmatite and granodiorite.The preferred interpretation of the geology is that the elliptical Mount Cormack Terrane is exposed as a window through an overlying allochthon composed of ophiolitic and volcano-sedimentary rocks of the Dunnage Zone. The emplacement of the allochthon probably postdated deposition of the Silurian Botwood Group. Paleontologic, lithologic, and structural considerations suggest that the sediments of the Mount Cormack Terrane were deposited at the eastern margin of Iapetus and are perhaps correlatives of rocks exposed in the Gander Zone. This implies that the Dunnage Zone has been thrust, probably in an eastwards direction, on a scale comparable with the allochthons mapped in the Scandinavian Caledonides and proposed for the Appalachians of Quebec and the United States.


1983 ◽  
Vol 57 (S14) ◽  
pp. 1-31 ◽  
Author(s):  
Olgerts L. Karklins

The High Bridge Group (Middle Ordovician), and the Lexington Limestone and Clays Ferry Formation (Middle and Upper Ordovician), of central Kentucky contain a diverse fossil invertebrate fauna, including cryptostome ptilodictyoids, the so-called “bifoliates,” as a distinctive element. The ptilodictyoid bryozoans there include nine species of six genera Escharopora, Graptodictya, Phyllodictya, Stictopora, Trigonodictya, and new genus Orectodictya in two families Ptilodictyidae and Rhinidictyidae. Three species are new: Escharopora eparmata, Trigonodictya cirrita, and Orectodictya pansa. Most of the species are closely related to ptilodictyoids occurring in the Middle Ordovician of New York and Minnesota. In Kentucky, Escharopora, Stictopora, and Trigonodictya occur in the oldest rocks exposed, and thus include the oldest bryozoans found in Kentucky. The stratigraphic distribution of ptilodictyoids in Kentucky reflects the disconformable contact between the Tyrone Limestone (High Bridge Group) and the overlying Lexington Limestone.


1987 ◽  
Vol 61 (2) ◽  
pp. 284-289 ◽  
Author(s):  
David M. Rohr ◽  
A. W. Potter

Rousseauspira teicherti, a new genus and species of an unusual, untwisted, horn-shaped gastropod operculum from shallow-subtidal limestones of the Upper Ordovician of Alaska and the Middle Ordovician of California, is described and compared to two other Ordovician opercula,CeratopeaUlrich, 1911, andTeiichispiraYochelson and Jones, 1968. The shell to which the operculum belonged is not yet known.


Author(s):  
Erika Fischer-Lichte

The introduction ‘Philhellenism and Theatromania’ retraces the emergence of these two phenomena in the German middle class. The year 1755 marks a watershed in this regard: it saw the publication of J. J. Winckelmann’s treatise Reflections on the Painting and Sculpture of the Greeks and the premiere of G. E. Lessing’s first domestic tragedy Miß Sara Sampson. Both share the common root and motivation once and for all to banish Frenchified German court culture. While Winckelmann’s treatise praised the ‘noble simplicity’ and ‘quiet greatness’ of the Greek masterpieces, Lessing’s play advocated new family values and the ideal of ‘naturalness’ as the true virtues of the middle class. The merging of Philhellenism as the cult of beauty with theatromania as the quest for identifying in a social group and as an individual provided the basic condition for staging Greek tragedies.


2020 ◽  
pp. 1-6
Author(s):  
Colin D. Sumrall ◽  
Daniel Phelps

Abstract A new genus and species of carneyellid edrioasteroid, Spiracarneyella florencei n. gen. n. sp., is described from the Upper Ordovician (Kaitian) Point Pleasant Formation of northern Kentucky and southern Ohio. Spiracarneyella n. gen. is characterized by having all five ambulacra curving clockwise around the theca, having small node-bearing interambulacral plates in the distal interambulacra, and having the periproct placement slightly offset to the right side of the CD interambulacrum. The oral area of carneyellids evolved by paedomorphosis of the oral plates covering the mouth. The straight ambulacra of Cryptogoleus and the spiraling ambulacra of Spiracarneyella n. gen. evolved by paedomorphosis and peramorphosis, respectively. UUID: http://zoobank.org/79733c8f-0bc8-4e7e-8f77-8508f576755c


2019 ◽  
Vol 94 (2) ◽  
pp. 273-278
Author(s):  
Björn Kröger ◽  
Juan Carlos Gutiérrez-Marco

AbstractThe order Intejocerida is an enigmatic, short-lived cephalopod taxon known previously only from Early–Middle Ordovician beds of Siberia and the United States. Here we report a new genus, Cabaneroceras, and a new species, C. aznari, from Middle Ordovician strata of central Spain. This finding widens the paleogeographic range of the order toward high-paleolatitudinal areas of peri-Gondwana. A curved conch, characteristic for the new genus, was previously unknown from members of the Intejocerida.UUID: http://zoobank.org/21f0a09c-5265-4d29-824b-6b105d36b791


1988 ◽  
Vol 62 (2) ◽  
pp. 218-233 ◽  
Author(s):  
John Mark Malinky

Concepts of the family Hyolithidae Nicholson fide Fisher and the genera Hyolithes Eichwald and Orthotheca Novak have been expanded through time to encompass a variety of morphologically dissimilar shells. The Hyolithidae is here considered to include only those hyolithid species which have a rounded (convex) dorsum; slopes on the dorsum are inflated, and the venter may be flat or slightly inflated. Hyolithes encompasses species which possess a low dorsum and a prominent longitudinal sulcus along each edge of the dorsum; the ligula is short and the apertural rim is flared. The emended concept of Orthotheca includes only those species of orthothecid hyoliths which have a subtriangular transverse outline and longitudinal lirae covering the shell on both dorsum and venter.Eighteen species of Hyolithes and one species of Orthotheca from the Appalachian region and Western Interior were reexamined in light of more modern taxonomic concepts and standards of quality for type material. Reexamination of type specimens of H. similis Walcott from the Lower Cambrian of Newfoundland, H. whitei Resser from the Lower Cambrian of Nevada, H. billingsi Walcott from the Lower Cambrian of Nevada, H. gallatinensis Resser from the Upper Cambrian of Wyoming, and H. partitus Resser from the Middle Cambrian of Alabama indicates that none of these species represents Hyolithes. Hyolithes similis is here included under the new genus Similotheca, in the new family Similothecidae. Hyolithes whitei is designated as the type species of the new genus Nevadotheca, to which H. billingsi may also belong. Hyolithes gallatinensis is referred to Burithes Missarzhevsky with question, and H. partitus may represent Joachimilites Marek. The type or types of H. attenuatus Walcott, H. cecrops Walcott, H. comptus Howell, H. cowanensis Resser, H. curticei Resser, H. idahoensis Resser, H. prolixus Resser, H. resseri Howell, H. shaleri Walcott, H. terranovicus Walcott, and H. wanneri Resser and Howell lack shells and/or other taxonomically important features such as a complete aperture, rendering the diagnoses of these species incomplete. Their names should only be used for the type specimens until better preserved topotypes become available for study. Morphology of the types of H.? corrugatus Walcott and “Orthotheca” sola Resser does not support placement in the Hyolitha; the affinities of these species are uncertain.


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