scholarly journals INDEX SPECIES OF UPPER ORDOVICIAN CONODONTS FROM THE TELETSKOE LAKESIDE ALTAI

2021 ◽  
Vol 2 (1) ◽  
pp. 191-195
Author(s):  
Olga T. Obut ◽  
Nikolay V. Sennikov ◽  
Dmitry A. Pecherichenko
Keyword(s):  
Upper Ordovician ◽  
Index Species ◽  
Gorny Altai ◽  
First Time

New data on the conodont index species from Upper Ordovician of the Teletskoe Lakeside, Gorny Altai, are presented. For the first time for this region representatives of the genera Plectodina and Belodina were found.

scholarly journals FIRST DATA ON THE LATE ORDOVICIAN CONODONTS SCYPHIODUS STAUFFER ON GORNY ALTAI

2021 ◽  
Vol 2 (1) ◽  
pp. 196-200
Author(s):  
Dmitry A. Pecherichenko ◽  
Olga T. Obut ◽  
Nikolay V. Sennikov
Keyword(s):  
Late Ordovician ◽  
Upper Ordovician ◽  
Gorny Altai ◽  
First Time

New data on conodonts from previously unstudied Upper Ordovician “Chechenek” Section on Gorny Altai are presented. Representatives of the conodont genus Scyphiodus Stauffer were discovered for the first time from this section.

A NEW DATA ON UPPER ORDOVICIAN CONODONTS FROM THE GURYANOVKA FORMATION, NORTHEAST OF GORNY ALTAI

2021 ◽  
pp. 3-11
Author(s):  
D. A. Pecherichenko ◽  
◽  
O. T. Obut ◽  
N. V. Sennikov ◽  
◽  
...  
Keyword(s):  
Upper Ordovician ◽  
Precise Position ◽  
Gorny Altai ◽  
Conodont Zone ◽  
Conodont Fauna ◽  
First Time

The detailed study of the Guryanovka Formation key sections at the northeast of Gorny Altai (Biya and Bura sections) for the first time revealed the representative collection of conodonts. The conodont fauna is composed of 12 species belong to 9 genera: Belodina compressa (Branson and Mehl, 1933), Phragmodus undatus Branson and Mehl, 1933, Panderodus gracilis (Branson and Mehl, 1933), Panderodus acostatus (Branson, Branson, 1947), Tasmanognatus careyi Burret, 1979, Aphelognathus sp., Panderodus sp., Drepanoistodus sp., Drepantodus sp., Colaptoconus sp., Paltodus sp., Scandodus sp. For the first time, the precise position of the P. undatus conodont Zone was defined in Gorny Altai (continuous Biya Section, base of unit 3).

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.

Muscular system of euconodont animals and their systematic position (Euconodontophylea)

2007 ◽  
Vol 15 (2) ◽  
pp. 229-235
Author(s):  
A.P. Kasatkina ◽  
G.I. Buryi
Keyword(s):  
South Africa ◽  
Physical State ◽  
Systematic Position ◽  
Visual Similarity ◽  
The Body ◽  
Muscular System ◽  
Upper Ordovician ◽  
Lower Carboniferous ◽  
Direction Of Movement ◽  
First Time

The muscular system of euconodont animals was studied in detail on the basis of the photographs of imprints from the Lower Carboniferous Shrimp Bed of Granton (Scotland), Upper Ordovician Soom Shale (South Africa), and Silurian Waukesha biota (North America). Superficial body structures are for the first time recognized for euconodont animals: external rings (annulation) (Panderodus imprint) and their traces (specimens 2 and 3 from Granton). This makes them looking like many invertebrates, such as annelids, priapulids, or pentastomids, and different from primitive chordates. In all other imprints of euconodont animals, a deep frontal break reaching their central part uncovers the inner transversal structures of the body, muscular fibers. As in invertebrates, they have different orientation. The medial apices of the fibers can be directed obliquely towards either the head (specimens 1, 2, 4, 5, 7 from Granton, and Promissum pulchrum Kovacs-Endrődy imprints) or the tail (specimens 2 and 6 from Granton) or to be perpendicular to the body axis (specimens 3-5 from Granton). Discontinuity of the transversal structures (specimens 1 and 6) appears to occur in the euconodont animals. This suggests that the transversal obliquely-oriented structures visible on the euconodont imprints, are not myomers typical of chordate animals. Differently directed position of medial apices of the obliquely-oriented muscular fibers depends, probably, on physical state (direction of movement) of the animal. The longitudinal median structure, in our opinion, cannot be considered a chord, but is rather a gut extending from pharynx to anus. Apparently, in spite of visual similarity, the euconodont animals under study cannot be classified as chordates, or chaetognaths, or pentastomids. Their muscular system differs from that of all known groups of animals and shows its own unique structure: its inner transversal structures are muscular fibers, which externally look like rings (annulation). This supports our earlier conclusion (Kasatkina & Buryi, 1997) that euconodonts constitute a separate phylum, Euconodontophylea Kasatkina & Buryi, 1997.

scholarly journals U-Pb age and trace elements composition of titanite from granites of Belokurikhinsky massif, Gorny Altai

Vestnik MGTU ◽  
2021 ◽  
Vol 24 (2) ◽  
pp. 168-177
Author(s):  
Sergey Gennadyevich Skublov ◽  
Maria Evgenyevna Mamykina ◽  
Nailya Gaptrahmanovna Rizvanova
Keyword(s):  
Trace Element Composition ◽  
Time Interval ◽  
Granite Massif ◽  
Eu Anomaly ◽  
Geochemical Study ◽  
Margin Of Error ◽  
Ree Distribution ◽  
Gorny Altai ◽  
First Time ◽  
Sr Method

As a result of isotope-geochemical study, the age data (U-Pb method, ID-TIMS) of titanite from the first phase granites of the Belokurikhinsky granite massif, Gorny Altai, were obtained for the first time. The concordant value of the titanite age of 255 ± 2 Ma coincides within the margin of error with the previously published results of dating micas from granites of the second and third phases of the Belokurikha massif by the Ar-Ar method (250 ± 3 Ma). At the same time, the results of dating differ significantly from the previously published age values for the granites of the Belokurikha massif (232 ± 5 Ma, U-Pb method for the monofraction of zircon grains; 245 ± 8 Ma, Rb-Sr method for the whole rocks). Therefore, there is every reason to narrow the time interval of the formation of the Belokurikha granite massif to 255-250 Ma. The study of the trace element composition of titanite by SIMS demonstrated their zonal structure. The central part of the titanite grain differs from the rim by a noticeably higher content of REE, Cr, Y, and Nb. The content of V, Zr and Ba decreases to a lesser extent towards the rim, the content of Sr and U remains constant. At the same time, the REE distribution spectra in the central and rim parts are conformal to each other, having a convex spectrum for LREE and a concave one for HREE. Titanite is characterized by a negative Eu-anomaly, the depth of which decreases to the rim of the grain. A negative Eu-anomaly indicates the co-crystallization of titanite and plagioclase. The REE distribution spectra in titanite from the Belokurikha massif correspond to the characteristics of a typical magmatic titanite from granitoids and differ significantly from the distribution spectra in metamorphic titanite.

Corynotrypa from the Ordovician of North America: colony growth in a primitive stenolaemate bryozoan

1994 ◽  
Vol 68 (2) ◽  
pp. 241-257 ◽  
Author(s):  
Paul D. Taylor ◽  
Mark A. Wilson
Keyword(s):  
North America ◽  
Colony Growth ◽  
Lateral Branch ◽  
Upper Ordovician ◽  
Primary Zone ◽  
Poorly Differentiated ◽  
Lateral Branches ◽  
First Time

Colonies of the runner-like bryozoans Corynotrypa delicatula (James) and C. inflata (Hall) are common encrusters of Middle and Upper Ordovician shells and hardgrounds, especially in Cincinnatian deposits. The simplicity of their zooids contrasts with complexities in the dynamics of colonial organization. Both species have uniserial branches that bifurcate at intervals and, in addition, give rise periodically to lateral ramifications. Although angles of bifurcation and lateral ramification each average about 80°, bifurcations and lateral ramifications are fundamentally different modes of branch multiplication. In C. delicatula new lateral branches have conspicuous secondary zones of astogenetic change distinguished by elongation of successively budded zooids. Unlike bifurcations, the first zooids in lateral branches in Corynotrypa are not linked to the parent branch by a narrow basal canal, and each new lateral branch can be regarded as a distinct subcolonial unit. The ancestrula, described here for the first time in an Ordovician species of Corynotrypa, has a poorly differentiated protoecium and initiates a primary zone of astogenetic change. Colony growth in Corynotrypa was more plastic than in many other bryozoan runners. The systematics of C. delicatula and C. inflata are revised, and a lectotype is chosen for the former species.

scholarly journals Upper Ordovician (Hirnantian) to Lower Silurian (Telychian, Llandovery) graptolite biostratigraphy of the Tielugou section, Shennongjia anticline, Hubei Province, China

PalZ ◽  
2021 ◽  
Author(s):  
Jörg Maletz ◽  
Chuanshang Wang ◽  
Wei Kai ◽  
Xiaofeng Wang
Keyword(s):  
South China ◽  
First Record ◽  
Hubei Province ◽  
Upper Ordovician ◽  
Lower Silurian ◽  
Index Species ◽  
Biostratigraphic Units

AbstractThe Tielugou section, Shennongjia Anticline, Hubei Province (China) includes a relatively complete succession of Hirnantian (latest Ordovician) to basal Telychian (Llandovery, early Silurian) graptolite faunas. The section shows the first record of a fauna of the late Aeronian Stimulograptus halli Biozone from South China, even though the index species was not reported. The Stimulograptus sedgwickii Biozone may not be represented, indicating a possible gap at the base of the Stimulograptus halli Biozone. The interval yields a number of taxa that are elsewhere reported to originate only in the Stimulograptus halli Biozone. The youngest graptolitic levels are included in the Spirograptus guerichi Biozone based on specimens of Parapetalolithus dignus and Parapetalolithus palmeus not known from earlier intervals. Spirograptus guerichi is not represented in the section. The Tielugou section provides the first detailed information on the faunas and thickness of the encountered biostratigraphic units for the Shennongija region.

New data on Ordovician–Silurian conodonts and stratigraphy from the Severnaya Zemlya Archipelago, Russian Arctic

2009 ◽  
Vol 146 (4) ◽  
pp. 497-516 ◽  
Author(s):  
P. MÄNNIK ◽  
O. K. BOGOLEPOVA ◽  
A. PÕLDVERE ◽  
A. P. GUBANOV
Keyword(s):  
Shallow Water ◽  
Ural Region ◽  
Russian Arctic ◽  
Upper Ordovician ◽  
Lower Silurian ◽  
The Baltic ◽  
Severnaya Zemlya ◽  
First Time ◽  
Severnaya Zemlya Archipelago ◽  
North Greenland

AbstractThirty samples from 22 sections collected by the SWEDARCTIC international expedition to Severnaya Zemlya in 1999 contained Ordovician and Silurian conodont faunas. Several taxa, including Apsidognathus cf. milleri, Aulacognathus cf. kuehni, Nudibelodina sensitiva, Ozarkodina broenlundi and Pterospathodus eopennatus, allow precise dating of the strata in this region for the first time. The occurrence of Aphelognathus pyramidalis and Rhipidognathus aff. R. symmetricus in samples from the Strojnaya Formation fits well with the earlier dating of these strata as latest Ordovician. However, Aphelognathus sp. in sample BG-99/14-a, collected from the upper Ushakov Formation, indicates that at least in the lower reaches of the Ushakov River the top of this formation is considerably younger than considered earlier: the sampled strata are Late, not Early Ordovician in age. In the Ordovician and Silurian the present-day Severnaya Zemlya region was dominated by extensive shallow-water, mainly semi-restricted basin environments with habitat specific faunas. The occurrence of Riphidognathus aff. R. symmetricus at some levels in the Upper Ordovician suggests extreme shallowing episodes in the basin. On Severnaya Zemlya, ‘normal-marine’ faunas (including Pt. eopennatus) invaded the distal peripheral regions of the wide shallow-water platform at times of maximum sea-level rise only. The occurrence of Oz. broenlundi and N. sensitiva indicates that in the early Silurian the Severnaya Zemlya basin was quite well connected to the basins over modern North Greenland as well as to the Baltic Palaeobasin. The lower Silurian conodont assemblages in the Vodopad to Samojlovich formations are most similar to those described from the eastern Timan–northern Ural region.

scholarly journals The Dawangou auxiliary GSSP (Xinjiang autonomous region, China) of the base of the Upper Ordovician Series: putting global chitinozoan biostratigraphy to the test

2010 ◽  
Vol 29 (2) ◽  
pp. 93-113 ◽  
Author(s):  
Jan Hennissen ◽  
Thijs R. A. Vandenbroucke ◽  
Xu Chen ◽  
Peng Tang ◽  
Jacques Verniers
Keyword(s):  
Black Shales ◽  
Upper Ordovician ◽  
Autonomous Region ◽  
Index Species ◽  
Xinjiang Autonomous Region

Abstract. The Dawangou section, an auxiliary Global Stratoype Section and Point (GSSP) for the base of the Upper Ordovician Series, was sampled for chitinozoans. The 32 samples taken from the black shales of the Saergan Formation, spanning the Pterograptus elegans, Didymograptus murchisoni and Nemagraptus gracilis graptolite biozones, yielded 6536 chitinozoan vesicles. In addition to a diverse endemic assemblage, species important for international correlation were recovered, which enables the subdivision of the Saergan Formation into two chitinozoan biozones, one subzone and one provisionally recognized biozone: the Baltoscandian Laufeldochitina striata Biozone and the Laurentian Lagenochitina sp. A (sensu Achab, 1984) (/Belonechitina hirsuta) Biozone, and the Belonechitina tuberculata Subzone are recognized based on the presence of the index species, while the Baltoscandian Laufeldochitina stentor Biozone is provisionally recognized on the presence of Laufeldochitina sp. A aff. striata sensu Grahn et al., 1996 which has a range confined to the latter biozone. One new chitinozoan species is described: Cyathochitina giraffa sp. nov. and two species were assigned to a different genus: Belonechitina tuberculata comb. nov. and Hercochitina seriespinosa comb. nov.

scholarly journals GRAPTOLITES FROM THE UPPER ORDOVICIAN SECTION «VERKHNYAYA KARASU» IN THE CENTRAL PART OF GORNY ALTAI

2021 ◽  
Vol 2 (1) ◽  
pp. 125-129
Author(s):  
Elena V. Lykova ◽  
Nikolay V. Sennikov
Keyword(s):  
Altai Mountains ◽  
Upper Ordovician ◽  
Gorny Altai ◽  
Stratigraphic Interval

Taxonomic complex of graptolites from the «Verkhnyaya Karasu» section have been studied. This section is located in the central part of Gorny Altai Mountains. The section covers a large stratigraphic interval: from upper Ordovician (Sandbian Stage) to Middle Silurian (Telychian Stage). For the Ordovician, the Bugryshikha, Khankhara and Tekhten' formations are distinguished. For the Silurian, the Vtorye Utyosy, Syrovaty, Polaty, Chesnokovka and Chesnokovka formations are distinguished. Previously, in this section no graptolites were found in the upper part of the Bugryshikha formation. There is a large and diverse complex of taxa collected in 2020. The graptolites assemblage from the upper part of the Bugryshikha formation consists of Reteograptus uniformis Mu et Zhang, Reteograptus geinitzianus Hall, Eoglyptograptus euglyphus Mitchell, Orthograptus apiculatus Elles et Wood, Orthograptus whitfieldi (Hall), Rectograptus truncatus (Lapworth), Rectograptus ex.gr. truncatus (Lapworth), Hustedograptus sp., Callograptus sp.

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