scholarly journals An integrated trilobite and conodont biostratigraphy across the base of the Laurentian Whiterockian Series (lower Middle Ordovician) at its stratotype, Whiterock Canyon Narrows, Nevada

2017 ◽  
Vol 91 (2) ◽  
pp. 294-317
Author(s):  
James Loch ◽  
Raymond Ethington
Keyword(s):  
New Species ◽  
Continuous Section ◽  
Conodont Biostratigraphy ◽  
Middle Ordovician ◽  
Conodont Zone

AbstractThe outcrop at Whiterock Canyon Narrows, Nevada, is the stratotype for the Middle Ordovician Whiterockian Series in Laurentia. Contrasts in the distribution of trilobites and conodonts between two parallel sections at the stratotype demonstrate the presence of an unconformity separating Ibexian faunas (the historic trilobite Zone J, the more recent restricted “Pseudocybele nasuta” trilobite Zone, theReutterodus andinusconodont Zone) from overlying Whiterockian faunas (Zone L, thePsephosthenaspis pseudobathyurustrilobite Zone, theOrthidiellabrachiopod Zone, theTripodus combsiconodont Zone). The unconformity represents the erosional loss of a minimum of 10 m of shale and bedded limestone within the upper Ninemile Formation. In comparison to more continuous section in the Ibex region, Utah, the equivalent to the thinPsephosthenaspis microspinosatrilobite Zone and, possibly, the uppermost interval of the underlying “P.nasuta” Zone are missing.Illaenus welchinew species is described from the Whiterockian faunas of the upper Ninemile and Antelope Valley formations.

Conodont biostratigraphy and paleoecology of Middle Ordovician rocks in eastern Oklahoma

1989 ◽  
Vol 63 (1) ◽  
pp. 92-107 ◽  
Author(s):  
Jeffrey A. Bauer
Keyword(s):  
New Species ◽  
Conodont Biostratigraphy ◽  
Middle Ordovician ◽  
Two New Species ◽  
Shallow Subtidal ◽  
Conodont Fauna ◽  
Carbonate Deposits

Conodonts from the upper Burgen, Tyner, and Fite Formations (Middle Ordovician) of eastern Oklahoma include two new species, Phragmodus harrisi and Plectodina tynerensis. The conodont fauna indicates that the upper Burgen through middle Tyner is Whiterockian (pre- to earliest Chazyan) and that the upper Tyner–Fite is probably Kirkfieldian in age.The Whiterockian Burgen–Tyner preserves a regressive succession of shoreface, lagoonal, and intertidal deposits. That change is reflected by the conodont succession, which shows replacement of a fauna dominated by species of Neomultioistodus, Scandodus?, and Paraprioniodus by one dominated by species of Phragmodus, Plectodina, and Erismodus.Carbonate deposits of the Kirkfieldian(?) upper Tyner and Fite Formations follow a major hiatus and reflect shallow, subtidal to intertidal conditions. The conodont fauna is composed of species of Aphelognathus, Plectodina, Curtognathus, Erismodus, and Oulodus, among others.

scholarly journals First record of a nonpaleotropical intejocerid cephalopod from Darriwilian (Middle Ordovician) strata of central Spain

2019 ◽  
Vol 94 (2) ◽  
pp. 273-278
Author(s):  
Björn Kröger ◽  
Juan Carlos Gutiérrez-Marco
Keyword(s):  
United States ◽  
New Species ◽  
New Genus ◽  
First Record ◽  
The United States ◽  
Central Spain ◽  
Middle Ordovician ◽  
A New Species

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

Nucularcidae: a new family of palaeotaxodont Ordovician pelecypods (Mollusca) from North America and Australia

2007 ◽  
Vol 44 (10) ◽  
pp. 1479-1501 ◽  
Author(s):  
John Pojeta Jr. ◽  
Christopher A Stott
Keyword(s):  
New Species ◽  
Type Species ◽  
New Genus ◽  
Late Ordovician ◽  
Eastern Canada ◽  
Middle Ordovician ◽  
New Family ◽  
Central Australia ◽  
Northeastern Usa ◽  
Subjective Synonym

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.

scholarly journals Die Gattung Erratencrinurus Krueger, 1971 (Trilobita; Ordovizium) aus baltoskandischen Geschieben

Fossil Record ◽  
2004 ◽  
Vol 7 (1) ◽  
pp. 69-132
Author(s):  
H.-H. Krueger
Keyword(s):  
New Species ◽  
Hard Rock ◽  
Late Ordovician ◽  
Middle Ordovician ◽  
Different Types ◽  
Single Spine ◽  
Pore Canals ◽  
Different Parts

Aus der mittel- bis oberordovizischen Trilobitenfamilie Encrinuridae, die in Baltoskandia durch die Untergattungen <i>Erratencrinurus</i> und <i>Celtencrinurus</i> repräsentiert wird, werden achtzehn Arten beschrieben, darunter die vier neuen Arten <i>Erratencrinurus (E.) sellinensis, E. (E.) heinrichi, E. (E.) praecapricornu</i> und <i>E. (E.) rhebergeni</i>. Das überwiegende Material stammt aus dem schwer zu präparierenden Ostseekalk. Die Tripp'sche Tuberkelformel wurde der <i>Erratencrinurus</i>-Gruppe angepasst; innerhalb der <i>Erratencrinurus</i>-Gruppe können drei verschiedene Schilder-Typen des scutum rostrale nachgewiesen werden. Unterschiedliche Tuberkeltypen bis hin zu extremen Stacheln wurden beschrieben. Außerdem kann eine Reduzierung von drei Thoraxialstacheln im Mittelordovizium zu einem im oberen Oberordovizium festgestellt werden. Verschiedene Regionen des Panzers von <i>Erratencrinurus (E.) sellinensis</i>, die Porenkanäle besitzen, werden dargestellt. Ein neuer Häutungstyp kann an Panzerhemden von <i>Erratencrinurus (E.) seebachi</i> beschrieben werden. <br><br> In Baltoscandia the Middle to Late Ordovician trilobite family <i>Encrinurida</i> is represented by the two subgenera <i>Erratencrinurus</i> and <i>Celtencrinurus</i>. Out of these 18 species, four new species are described herein. Most of the material comes from the Ostseekalk which is an extremely hard rock and thus difficult to preparate. The tubercle formula after Tripp is applied to the <i>Erratencrinurus</i> group and led to the distinction of three different types of scutum rostrale shields. Various types of tubercles which may even pass into extreme spines are described. The number of thoracic spines becomes reduced from three spines in Middle Ordovician taxa to a single spine in youngest Ordovician species. Different parts of the carapace of <i>Erratencrinurus sellinensis</i> with pore canals are illustrated and a new moulting type of E. <i>seebachi</i> is introduced. New species are <i>E. sellinensis. E. heinrichi, E. praecapricornu and E. (E.) rhebergeni.</i> <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20040070106" target="_blank">10.1002/mmng.20040070106</a>

Flexible crinoids from the Upper Ordovician Maquoketa Formation of the northern midcontinent and the evolution of early flexible crinoids

2001 ◽  
Vol 75 (2) ◽  
pp. 370-382 ◽  
Author(s):  
James C. Brower
Keyword(s):  
New Species ◽  
North America ◽  
Late Ordovician ◽  
Upper Ordovician ◽  
Middle Ordovician

Three flexible crinoids occur in the Upper Ordovician Maquoketa Formation of Illinois, Iowa, and Minnesota:Protaxocrinus girvanensisRamsbottom, 1961,Clidochirus anebosnew species, andProanisocrinus oswegoensis(Miller and Gurley, 1894).Protaxocrinus girvanensisis also found in the Upper Ordovician of Scotland which indicates that the ocean was narrow enough to allow at least one crinoid species to cross the barrier. The Upper Ordovician of North America and Scotland also share many common crinoid genera. Both phenetic and cladistic methods result in similar phylogenies of flexible crinoids.Protaxocrinuswas derived from a cupulocrinid ancestor during the Middle Ordovician.Clidochirusevolved fromProtaxocrinusor its ancestral stock prior to the Richmondian of the Late Ordovician. The RichmondianProanisocrinusand later anisocrinids are most closely related toClidochirusor its immediate predecessor. Thus, three major lineages of flexible crinoids,Protaxocrinus(taxocrinid group),Clidochirus(icthyocrinid), andProanisocrinus(anisocrinids and homalocrinids), appeared during the Ordovician. Despite their rarity during the Ordovician, all three flexible lineages survived the Latest Ordovician extinction, whereas their more abundant and successful cupulocrinid ancestors were eliminated.

Middle Ordovician Echinoderms from Northern Illinois and Southern Wisconsin

1975 ◽  
Vol 49 (S7) ◽  
pp. 1-74 ◽  
Author(s):  
Dennis R. Kolata
Keyword(s):  
New Species ◽  
New Genus ◽  
Carbonate Sediments ◽  
North Central ◽  
Middle Ordovician ◽  
South Central ◽  
The Family ◽  
Central Illinois ◽  
First Time ◽  
One New Species

Echinoderms of the Middle Ordovician Platteville and lower Galena Groups of north-central Illinois and south-central Wisconsin are represented by at least seven classes including the Homoiostelea, Cystoidea, Crinoidea, Stelleroidea, Edrioasteroidea, Cyclocystoidea, Echinoidea, and possibly Holothuroidea. The most abundant and diverse echinoderms are monocyclic and dicyclic inadunate and camerate crinoids, of which the cupulocrinids and glyptocrinids are best represented. Thirteen new species and one new genus of crinoids are described:Cremacrinus guttenbergensis, Anulocrinus forrestonensis, Isotomocrinus minutus, Carabocrinus oogyi, Dendrocrinus? springeri, Merocrinus britonensis, Cupulocrinus plattevillensis, C. molanderi, Reteocrinus rocktonensis, R. spinosus, Traskocrinus mahlburgi(n. gen. et sp.),Rhaphanocrinus buckleyi, Glyptocrinus charltoni, andG. pustulosis.One new species of rhombiferan cystoid,Coronocystis durandensis, is also described. Echinoids of the family Bothriocidaridae (Bothriocidaris solemin. sp. andNeobothriocidaris templetonin. sp.) are reported for the first time from North America and appear to be the earliest recorded occurrence. Remains of a third bothriocidarid characterized by coalesced podial pores have also been discovered. Light and scanning electron microscopy of well preserved cyclocystoid specimens reveal a number of previously undescribed morphologic features of the central disc and submarginal ring that may shed some light on their functional morphology.Cupulocrinus gracilisRamsbottom from the Upper Drummuck Group Starfish Bed at Thraive Glen near Girvan, Scotland, is here reassigned toC. drummuckensisn. sp.Echinoderms are associated with an abundant and diverse fauna consisting largely of suspension feeders, primarily strophomenid and orthid brachiopods and trepostome and cryptostome bryozoans. Other common groups include corals, trilobites, sponges, and mollusks. Filamentous brown, foliose red and siphonaceous green algae are associated with the fauna at some localities.Carbonate rocks of both the limestone and dolostone facies of the Platteville (Briton, Walgreen and Forreston Members) and lower Galene Groups in the study area consist primarily of abundant shelly invertebrates occurring as whole and broken, unabraded, commonly articulated remains “floating” in a calcisiltite matrix that is highly bioturbated. Carbonate sediments appear to have been deposited in a near-to below wave base, highly stable, open marine environment characterized by low depositional slopes, good circulation and low terrigenous influx.

Masonoceras, a new karagandoceratid ammonoid from the lower Mississippian (lower Osagean) of Kentucky

2002 ◽  
Vol 76 (3) ◽  
pp. 574-577 ◽  
Author(s):  
David M. Work ◽  
Walter L. Manger
Keyword(s):  
New Species ◽  
Type Species ◽  
New Genus ◽  
Systematic Position ◽  
Ventral Lobe ◽  
Formal Description ◽  
Ventral Margin ◽  
Borden Formation ◽  
Conodont Zone ◽  
A New Species

Karagandoceratids are a rare offshoot of the Prionoceratinae, resembling that subfamily in general conch form and sutural ontogeny, but differing by possession of an acute ventral margin and an increasingly trifid ventral lobe. The systematic position of the Karagandoceratidae has been controversial [see Bartzsch and Weyer (1988) for an exhaustive review]. The nominate genus, Karagandoceras Librovitch, 1940 (type species, K. galeatum), possesses a weakly divided ventral lobe which has led authors to refer it to both the Praeglyphioceratina (Ruzhencev, 1960, 1962; Bogoslovsky, 1971; Ruzhencev and Bogoslovskaya, 1978; Bogoslovskaya et al., 1999; Kusina, 2000) and the Goniatitina (Weyer, 1965, 1972; Kullmann, 1981). Discovery of an ancestral karagandoceratid genus, gen. nov. I aff. Karagandoceras Bartzsch and Weyer, 1988, in the early Tournaisian Siphonodella sandbergi conodont Zone in Germany provided clarification on the proximate origin of Karagandoceras and provided a plausible link to the early Tournaisian prionoceratin genus Nicimitoceras Korn, 1993 (type species, Imitoceras subacre Vöhringer, 1960). Bartzsch and Weyer (1988) proposed a karagandoceratid phylogeny beginning with gen. nov. I aff. Karagandoceras in the early Tournaisian, progressing through Karagandoceras in the middle Tournaisian, and culminating with a third, descendent genus, gen. nov. II aff. Karagandoceras (typical species, Karagandoceras bradfordi Manger, 1971), early in the late Tournaisian. Bartzsch and Weyer (1988) elected to leave both the initial and final members of this lineage, gen. nov. I and gen. nov. II aff. Karagandoceras, in open nomenclature pending discovery of more completely preserved material. Discovery of superbly preserved representatives of a new species of gen. nov. II aff. Karagandoceras from the Borden Formation in northeastern Kentucky provides additional sutural and morphological details that support Bartzsch and Weyer's phylogenetic interpretation and makes formal description of this terminal karagandoceratid taxon (herein designated Masonoceras new genus) possible.

Telephinaand Other Trilobites from the Pratt Ferry Beds, Ordovician of Alabama, U.S.A.

2014 ◽  
Vol 88 (3) ◽  
pp. 545-555 ◽  
Author(s):  
Frederick C. Shaw
Keyword(s):  
North America ◽  
North American ◽  
Original Description ◽  
Eastern North America ◽  
Zone Boundary ◽  
Middle Ordovician ◽  
Conodont Zone ◽  
Stratigraphic Range ◽  
Single Locality

The Pratt Ferry beds are a three meter thick bioclastic carbonate unit containing thePygodus serrus–P. anserinusconodont zone boundary and lying just below theNemagraptus gracilisgraptolite zone at a single locality in Alabama.TelephinaMarek at Pratt Ferry and other eastern North American localities is represented by at least six species. These are judged widespread and in part conspecific with Scandinavian or Asian forms of similar age. Most of the fifteen Appalachian telephinid species proposed by Ulrich (1930) are reviewed and some synonymized.BevanopsisCooper is present, extending its stratigraphic range viaB. buttsi(Cooper). The original description ofCeraurinella buttsiCooper is augmented. Other recorded but poorly represented genera includeAmpyxina,Arthrorhachis,Calyptaulax,Hibbertia,Lonchodomas,Mesotaphraspis,Porterfieldia, andSphaerexochus. The entire faunule represents a mixture of ‘inshore’ and ‘offshore’ or planktonic faunal elements rarely seen elsewhere in the latest Middle Ordovician (Darriwilian) of eastern North America.

Cambrian and Ordovician linguliform brachiopods from the Shallow Bay Formation (Cow Head Group), western Newfoundland

2001 ◽  
Vol 75 (2) ◽  
pp. 241-260 ◽  
Author(s):  
Sean P. Robson ◽  
Brian R. Pratt
Keyword(s):  
New Species ◽  
Continental Slope ◽  
Head Group ◽  
Lower Paleozoic ◽  
Middle Cambrian ◽  
Middle Ordovician ◽  
Upper Cambrian ◽  
Three New Species ◽  
Brachiopod Fauna ◽  
Shallow Bay

Linguliform brachiopods were recovered from the Upper Cambrian Downes Point Member (lower Sunwaptan) and from the Middle Ordovician Factory Cove Member (Arenig) of the Shallow Bay Formation, Cow Head Group, of western Newfoundland. These rocks are a series of Middle Cambrian to Middle Ordovician conglomerates, lime mudstones, and shales that formed a sediment apron at the base of the lower Paleozoic continental slope of Laurentia. The linguliform brachiopod fauna consists of sixteen species assigned to twelve genera. Three new species are described: Picnotreta lophocracenta, Neotreta humberensis, and Siphonotretella parvaducta.

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