scholarly journals The only known cyclopygid–‘atheloptic’ trilobite fauna from North America: the upper Ordovician fauna of the Pyle Mountain Argillite and its palaeoenvironmental significance

2012 ◽  
Vol 149 (6) ◽  
pp. 964-988 ◽  
Author(s):  
ALAN W. OWEN ◽  
DAVID L. BRUTON
Keyword(s):  
New Species ◽  
North America ◽  
Deep Water ◽  
Benthic Fauna ◽  
Taxonomic Diversity ◽  
Relative Depth ◽  
Upper Ordovician ◽  
Brachiopod Fauna ◽  
Depth Ranges ◽  
One New Species

AbstractThe trilobite fauna of the upper Ordovician (middle Katian) Pyle Mountain Argillite comprises a mixture of abundant mesopelagic cyclopygids and other pelagic taxa and a benthic fauna dominated by trilobites lacking eyes. Such faunas were widespread in deep water environments around Gondwana and terranes derived from that continent throughout Ordovician time but this is the only known record of such a fauna from North America and thus from Laurentia. It probably reflects a major sea level rise (the ‘Linearis drowning events’) as does the development of coeval cyclopygid-dominated deep water trilobite faunas in terranes that were marginal to Laurentia and are now preserved in Ireland and Scotland. The Pyle Mountain Argillite trilobite fauna occurs with a deep water Foliomena brachiopod fauna and comprises 22 species. Pelagic trilobites (mostly cyclopygids) constitute 36% of the preserved sclerites, and 45% of the fauna is the remains of trilobites lacking eyes, including one new species, Dindymene whittingtoni sp. nov. Three species of cyclopygid are present, belonging in Cyclopyge, Symphysops and Microparia (Heterocyclopyge). Cyclopygids are widely thought to have been stratified in the water column in life and thus their taxonomic diversity reflects the relative depths of the sea-beds on which their remains accumulated. A tabulation of middle and upper Katian cyclopygid-bearing faunas from several palaeoplates and terranes arranged on the basis of increasing numbers of cyclopygid genera allows an assessment of the relative depth ranges of the associated benthic taxa. The Pyle Mountain Argillite fauna lies towards the deeper end of this depth spectrum.

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.

A new species and a new record of alpheid shrimps of the genus Salmoneus Holthuis, 1955 (Crustacea: Decapoda: Alpheidae) from Iran

Zootaxa ◽  
2020 ◽  
Vol 4838 (4) ◽  
pp. 503-514
Author(s):  
HOSSEIN ASHRAFI ◽  
ZDENĚK ĎURIŠ ◽  
REZA NADERLOO
Keyword(s):  
New Species ◽  
Persian Gulf ◽  
Benthic Fauna ◽  
Species Group ◽  
Gulf Of Oman ◽  
Small Series ◽  
The Persian Gulf ◽  
One New Species ◽  
A New Species ◽  
Reddish Orange

Extensive samplings of benthic fauna along the Iranian coastlines of the Persian Gulf and Gulf of Oman during 2018–2019 resulted in a small series of shrimps of the alpheid genus Salmoneus. Based on a thorough examination of this material, as well as previously collected specimens, one new species, S. rashedi n. sp., is described, whilst a significant range extension of S. chadwickae Ďuriš & Horká, 2016 is reported. Salmoneus rashedi n. sp. is a member of S. gracilipes species group. The present new species differs from other species of the group by a longer rostrum with a short dorsal crest and a single ventral rostral tooth; the species occurs in two colour forms from yellow to reddish orange with some transverse red bands. 

Upper Ordovician graptolites from the top Lower Hartfell Shale Formation (D. clingani and P. linearis zones) near Moffat, southern Scotland

1982 ◽  
Vol 72 (4) ◽  
pp. 229-255 ◽  
Author(s):  
S. Henry Williams
Keyword(s):  
New Species ◽  
North America ◽  
Upper Ordovician ◽  
The North ◽  
Continuous Sequence ◽  
Two New Species ◽  
Shale Formation ◽  
First Time

ABSTRACTThe top 9 m of Lower Hartfell Shale has been collected in 10 cm samples through a continuous sequence on the North Cliff at Dob's Linn. The boundary between the Dicranograptus clingani and Pleurograptus linearis zones is denned for the first time in a measured section, 5.0 m below the top of the Lower Hartfell Shale, with the excavation of the North Cliff proposed as stratotype. The late D. clingani Zone is characterised by Dicranograptus ramosus?, Dicellograptus moffatensis, D. flexuosus [= D. forchhammeri], Climacograptus dorotheus, Glyptograptus daviesi sp. nov., Diplograptus? pilatus sp. nov., Neurograptus margaritatus and Corynoides calicularis. The P. linearis Zone is characterised by Pleurograptus linearis linearis, Amphigraptus divergens divergens, Leptograptus capillaris, Dicellograptus elegans elegans, D. pumilis, D. carruthersi and Climacograptus tubuliferus. A range chart is provided and an attempt is made at a revised correlation of the Scottish succession with coeval zonal sequences in North America and Australia. Twenty-one taxa are described including the two new species noted above.

Arctic and alpine agarics from Alaska and Canada

1973 ◽  
Vol 51 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Orson K. Miller Jr. ◽  
Gary A. Laursen ◽  
Barbara M. Murray
Keyword(s):  
New Species ◽  
North America ◽  
Arctic Tundra ◽  
Alpine Tundra ◽  
Camera Lucida ◽  
Ecological Information ◽  
First Time ◽  
One New Species

Eight species of agarics in the Basidiomycetes from arctic and alpine tundra in Alaska and adjacent Canada are included. Four taxa are reported from North America for the first time including one new species. One taxon is reported for the first time from arctic tundra in North America. New ecological information, host ranges, and fruiting periods are presented for all taxa. Camera lucida drawings are included for five taxa.

Taxonomy and correlation of Lower Triassic (Spathian) segminate conodonts from Oman and revision of some species ofNeospathodus

1995 ◽  
Vol 69 (1) ◽  
pp. 110-122 ◽  
Author(s):  
M. J. Orchard
Keyword(s):  
New Species ◽  
North America ◽  
Lower Triassic ◽  
Type Material ◽  
Western North America ◽  
Key Species ◽  
One New Species ◽  
Distinct Taxon

Exceptionally well preserved Lower Triassic conodonts from Oman include an array ofNeospathodusspecies, many of which are new. Those from the upper Lower Triassic, or Spathian, are described in conjunction with a restudy of conodont type material from Chios, Greece, and an assessment of contemporary collections from Pakistan and western North America. The taxonomic scope of three key species from Chios,Neospathodus homeri, N. triangularis, andN. gondolelloides, is revised. Seven new species are described from Oman:N. abruptus, N. brevissimus, N. brochus, N. crassatus, N. curtatus, N. pusillus, andN. symmetricus;and one new species,N. clinatus, is described from Pakistan. The alliedIcriospathodus collinsoniis also described from Oman. The occurrence and range ofNeospathodusspecies are presented in the context of the ammonoid succession in the Spathian of North America. BothN. homeriandN. triangularis, as revised, have shorter ranges and are more age diagnostic than previously thought.Neospathodus gondolelloidesis a distinct taxon, and not synonymous withChiosella timorensis.Five informal faunal divisions are identified based onNeospathodusand allied species. In ascending stratigraphic order, these are typified byIcriospathodus collinsoni, Neospathodus homeri, N. triangularis, N. symmetricus, andN. gondolelloides.Oman collections represent three of these faunas, which occur also in theColumbitesthroughProhungarites/Subcolumbitesammonoid beds of western U.S.A.

Famennian rhynchonellides (Brachiopoda) from deep-water facies of the Ougarta Basin (Saoura Valley, Algeria)

2015 ◽  
Vol 152 (6) ◽  
pp. 1009-1024 ◽  
Author(s):  
BERNARD MOTTEQUIN ◽  
FATIMA ZOHRA MALTI ◽  
MADANI BENYOUCEF ◽  
CATHERINE CRÔNIER ◽  
LOUISA SAMAR ◽  
...  
Keyword(s):  
New Species ◽  
Deep Water ◽  
Sea Floor ◽  
Lower Upper ◽  
Northern Margin ◽  
Eastern Margin ◽  
South Eastern ◽  
First Time ◽  
One New Species ◽  
Water Facies

AbstractIn the Saoura Valley (Ougarta Basin, Saharan Algeria), the lower–upper Famennian part of the essentially shally Marhouma Formation is characterized by deep-water facies and includes horizons rich in ammonoids (goniatites and clymeniids) and blind to eye-reduced phacopide trilobites. They are also rich in small-sized and smooth rhynchonellide brachiopods, investigated here for the first time in order to detail their post-Kellwasser recovery. Rhynchonellides clearly predominate in the brachiopod assemblages (representing 90% of the whole assemblage, with 10 species) composed otherwise of athyridides, orthides and spiriferides. Rhynchonellides are mostly represented by relatively flat leiorhynchids and rozmanariids consistent with poor oxygenation on the sea floor. One new species is described (Evanidisinurostrum saouraensesp. nov.); four genera, previously known only from the south-eastern margin of Laurussia, are reported for the first time from the northern margin of Gondwana: the leiorhynchidSphaeridiorhynchusand the rozmanariidsLeptoterorhynchus, PugnariaandNovaplatirostrum.

scholarly journals CURRENT VIEWS ON THE DIVERSITY AND DISTRIBUTION OF DEEP-WATER MEIOBENTHOS AT THE TURKISH SHELF (BLACK SEA)

2017 ◽  
Vol 14 ◽  
pp. 60-73
Author(s):  
Nelli G. Sergeeva ◽  
Derya Ürkmez
Keyword(s):  
Black Sea ◽  
Deep Water ◽  
Benthic Fauna ◽  
Taxonomic Diversity ◽  
The Black Sea ◽  
Depth Range ◽  
Free Living ◽  
Higher Taxa ◽  
Strong Current ◽  
High Level

Deep-water meiobenthos of Turkish shelf has been evaluated at the Black Sea exit of İstanbul Strait (Bosphorus) and off Sinop peninsula as a result of three scientific cruises. Taxonomic diversity of meiobenthos communities was studied at the Black Sea exit of Bosphorus on a transect with a depth range of 75-300 m. The bottom sediments were collected at the area during two cruises, on board RV "Arar'' (of Turkey) and ''Maria S. Merian" (of Germany) in November 2009 and April 2010, respectively. Data on meiobenthos inhabiting both normoxic and extreme conditions was collected in the studied area and meiobenthos composition included 26 high level taxa. In addition, 2-3 morphotypes of benthic fauna were recorded as incertae sedis, which require further study. The number of higher taxa decreased from 22 to 14-8 when switching from oxygenic conditions (50-125 m) to the anoxic hydrogen sulphide environment (226-300 m). The constant components of meiobenthos included protists (Ciliophora, Gromiidea and soft-shelled Foraminifera), and metazoans were constantly represented by Nematoda and Harpacticoida. In 2011, a quantitative study on meiobenthic composition of the oxic/anoxic interface at the western part off Sinop Peninsula (Southern Black Sea) has also been investigated. The material was collected by ROVs during the expedition (Black Sea Leg) of the exploration vessel (E/V) Nautilus. Results showed that the taxa composition of meiobenthos ranged from 4 to 10 major groups. Free-living marine nematodes were numerically the dominant taxon at each station. Total abundances decreased in parallel to increasing water depth, hence decreasing oxygen levels.

Stratigraphic and Paleogeographic Significance of An Upper Ordovician Acritarch Flora from the Maquoketa Shale, Northeastern Missouri, U.S.A.

1999 ◽  
Vol 73 (S51) ◽  
pp. 1-38 ◽  
Author(s):  
Reed Wicander ◽  
Geoffrey Playford ◽  
Eddie B. Robertson
Keyword(s):  
New Species ◽  
North America ◽  
Type Species ◽  
Low Energy ◽  
New Genera ◽  
Upper Ordovician ◽  
Important Species ◽  
Maquoketa Shale

A well-preserved and moderately diverse acritarch assemblage was recovered from the upper Ordovician Maquoketa Shale of northeastern Missouri. Based on graptolite and conodont evidence, the Maquoketa in northeastern Missouri is considered Richmondian (=Ashgill) in age.The acritarch assemblage comprises 28 species, distributed among 17 genera including two new genera,CaelatosphaeraandStictosoma.There are 11 new species,Baltisphaeridium adiastaltum, Caelatosphaera verminosa(type species),Dorsennidium undosum, Elektoriskos aktinotos, Lophosphaeridium acinatum, L. varum, Micrhystridium hirticulum, M. prolixum, Peteinosphaeridium accinctulum, P. septuosum, andStictosoma gemmata(type species); together with two species similar to previously named species and three species left in open nomenclature. Cosmopolitan and stratigraphically important species identified includeBaltisphaeridium perclarumLoeblich and Tappan, 1978;Cheleutochroasp. cf.C. diaphorosaTurner, 1984;Dorsennidium hamii(Loeblich, 1970) Sarjeant and Stancliffe, 1994;Excultibrachium concinnumLoeblich and Tappan, 1978;Orthosphaeridium insculptumLoeblich, 1970;O. rectangulare(Eisenack, 1963) Eisenack, 1968, andVillosacapsula setosapellicula(Loeblich, 1970) Loeblich and Tappan, 1976.Polygonium gracileVavrdová, 1966 emend. Sarjeant and Stancliffe, 1994 andMicrhystridium hirticulumnew species dominate the assemblage, followed byDorsennidium undosumnew species,Baltisphaeridium oligopsakiumLoeblich and Tappan, 1978,Veryhachiumsp. cf.V. oklahomenseLoeblich, 1970,Peteinosphaeridium accinctulumnew species, andLophosphaeridium acinatumnew species. Additionally, the palynoflora contains chitinozoans, scolecodonts, cryptospores, and the enigmatic palynomorphGloeocapsomorpha priscaZalessky, 1917 emend. Foster, Reed, and Wicander, 1989.Paleontologic-palynologic and sedimentologic evidence indicates that the Maquoketa Shale at the two studied localities accumulated under low energy, somewhat offshore, and unrestricted marine conditions. The present Maquoketa Shale acritarch palynoflora shows greatest similarity to those of the Sylvan Shale (Ashgill; Richmondian) of Oklahoma and the Maquoketa Shale (Caradoc and Ashgill) of Kansas. Whereas there are some cosmopolitan acritarch species present in the Maquoketa Shale, its palynoflora shows no pronounced similarity with age-equivalent acritarch suites from outside of North America.

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