scholarly journals Late Ordovician Palynomorphs

1985 ◽  
Vol 4 (1) ◽  
pp. 11-26 ◽  
Author(s):  
S. G. Molyneux ◽  
F. Paris

Abstract. ACRITARCHSOrdovician acritarchs have been recorded in five core samples collected between 2520 ft. and 3000 ft. in Well E1-81, and ten cutting samples taken between 12150 ft. and 13240 ft. in Well J1-81A. All the assemblages recovered are of Late Ordovician age; no Early Ordovician or Middle Ordovician assemblages have been identified.Investigations have so far concentrated on the acritarch assemblages from Well El-81. The highest three Ordovician samples from depths of 2520 to 2550 ft., 2552 to 2557 ft., and 2562 to 2567 ft., yielded similar assemblages which include Veryhachium irroratum, V. cf. lairdii, V. oklahomense?, V. subglobosum, V. trispinosum, Villosacapsula setosapellicula and a new species, Striatotheca sp. A. Navifusa similis? is represented by one specimen in the sample from 2552 to 2557 ft. Another specimen from the same sample is tentatively referred to Aremoricanium syringosagis. Specimens of Baltisphaeridium, Peteinosphaeridium, Leiofusa and Eupoikilofusa occur throughout the interval 2520 to 2567 ft. but are rare. Commonly occurring species include V. irroratum and V. setosapellicula. V. irroratum has been recorded from the Middle Ordovician of North America (Loeblich & Tappan, 1969) and the Caradoc of England (Turner, 1984) but Cramer & Diez (1979) maintain that it has its acme in the Ashgill. V. setosapellicula is common in the Sylvan Shale of Oklahoma (Loeblich, 1970) which is generally understood to be of Ashgill age, but is rare in the Eden Shale (Caradoc) of Indiana (Colbath, 1979) and in the type section of the Caradoc Series in Shropshire, England (Turner, 1984). . . .

2001 ◽  
Vol 75 (2) ◽  
pp. 370-382 ◽  
Author(s):  
James C. Brower

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.


1986 ◽  
Vol 60 (S20) ◽  
pp. 1-47 ◽  
Author(s):  
J. Keith Rigby ◽  
A. W. Potter

Extensive silicified faunules of Middle and Late Ordovician sphinctozoan sponges have been assembled from the northern part of the eastern Klamath Mountains in northern California. The sponges are from eugeosynclinal rocks that are the westernmost Middle Ordovician to Late Devonian rocks at that latitude in North America. Seventeen new species occur in the assemblages, including 10 porate and 7 aporate forms. New genera of porate forms areAmblysiphonelloidesandCorymbospongia, and new porate species include:Amblysiphonella grossa, Amblysiphonelloides tubula, A. reticulata, Imperatoria mega, I. media, I. minima, I. irregularis, Corymbospongia adnata, C. mica, andC.(?)perforata.These are the first reported occurrences ofAmblysiphonellaandImperatoriain the Ordovician. New aporate genera areCystothalamiellaandPorefieldia, and new aporate species include:Cystothalamiella ducta, C. craticula, C. tuboides, Porefieldia robusta, Girtyocoelia epiporata, andG. canna.This is the oldest known occurrence ofGirtyocoelia, which is generally considered a Late Paleozoic form.Cliefdenella obconican. sp. is characterized by an obconical growth form in contrast to other species of the genus that are more massive or explanate.Cliefdenellais considered here as an imperforate sphinctozoan.Minor isolated hexactines and hexactine-derived spicules of Hexactinellida were associated with the sphinctozoans. No particular taxa within the class can be distinguished from these individual elements.


1988 ◽  
Vol 25 (10) ◽  
pp. 1595-1607 ◽  
Author(s):  
Brian R. Pratt

The Rabbitkettle Formation is a widespread lower Paleozoic unit in the northern Cordillera. A trilobite faunule collected from the middle part of the type section and described here documents an early Ibexian (Early Ordovician) age for this interval and provides the first biostratigraphic reference point for the type section. This faunule is dominated by the agnostoid Micragnostus, the leiostegiid Leiostegium, and the remopleuridid Kainella. These genera and rarer taxa have North American, South American, and Austral-Asian affinities. A new species, Kainella eleutherolfi, is established.


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


Parasitology ◽  
2007 ◽  
Vol 135 (2) ◽  
pp. 203-215 ◽  
Author(s):  
T. R. RAFFEL ◽  
T. BOMMARITO ◽  
D. S. BARRY ◽  
S. M. WITIAK ◽  
L. A. SHACKELTON

SUMMARYGiven the worldwide decline of amphibian populations due to emerging infectious diseases, it is imperative that we identify and address the causative agents. Many of the pathogens recently implicated in amphibian mortality and morbidity have been fungal or members of a poorly understood group of fungus-like protists, the mesomycetozoans. One mesomycetozoan, Amphibiocystidium ranae, is known to infect several European amphibian species and was associated with a recent decline of frogs in Italy. Here we present the first report of an Amphibiocystidium sp. in a North American amphibian, the Eastern red-spotted newt (Notophthalmus viridescens), and characterize it as the new species A. viridescens in the order Dermocystida based on morphological, geographical and phylogenetic evidence. We also describe the widespread and seasonal distribution of this parasite in red-spotted newt populations and provide evidence of mortality due to infection.


1994 ◽  
Vol 68 (3) ◽  
pp. 451-460 ◽  
Author(s):  
Patrick R. Racheboeuf ◽  
Paul Copper ◽  
Fernando Alvarez

Cryptonella? cailliaudi Barrois, 1889, from the Lower Devonian of the Armorican Massif, is tentatively assigned to the athyridid brachiopod genus Planalvus Carter, thus far known only from the Lower Carboniferous of eastern North America. In addition, a new species, Planalvus rufus, is described from the Bois-Roux Formation (Pragian) of Brittany, France. These French species are small brachiopods with complex spiralial and jugal structures, which permit assignment to the order Athyridida.


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.


Zootaxa ◽  
2018 ◽  
Vol 4375 (3) ◽  
pp. 409
Author(s):  
PAUL E. MAREK ◽  
JACKSON C. MEANS ◽  
DEREK A. HENNEN

Millipedes of the genus Apheloria Chamberlin, 1921 occur in temperate broadleaf forests throughout eastern North America and west of the Mississippi River in the Ozark and Ouachita Mountains. Chemically defended with toxins made up of cyanide and benzaldehyde, the genus is part of a community of xystodesmid millipedes that compose several Müllerian mimicry rings in the Appalachian Mountains. We describe a model species of these mimicry rings, Apheloria polychroma n. sp., one of the most variable in coloration of all species of Diplopoda with more than six color morphs, each associated with a separate mimicry ring.


Sign in / Sign up

Export Citation Format

Share Document