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Lower Ordovician (Volkhovian-Kundan) conodonts from Hagudden, northern Oeland, Sweden.
No full textThis paper presents taxonomical description of Early Ordovician conodonts recovered from the limestones at Hagudden, in northern Oeland (Sweden). 33 samples yielded about 20.000 conodont elements. 18 genera and 36 species are described. Two genera are emended and redefined in terms of multielement taxonomy. Two new species are described. The fauna is typical of the Baltic region. The conodont zones are correlated with the trilobite zones. The faunas of the Volkhovian Stage and the Hunderumian Substage and Valastean Substage of the Kundan Stage are discussed
An upper Llandovery conodont fauna from Eastern Hall Land, North Greenland. , 23 (1): 103-112.
No full textA conodont fauna of Early Silurian age (Llandovery) has been recorded from eastern Hall Land, North Greenland. The faunal asociation comprises Apsidognathus tuberculatus Walliser, Carniodus carnulus Walliser, Distomodus sp. and some species of Panderodus. The multielement apparatus of Ozarkodina hadra (Nicoll and Rexroad) is proposed here and a new species of Pterospathodus is described
The suprageneric classification of some Ordovician prioniodontid conodonts
No full textPhylogenetic relationships among higher taxa within the conodonts that developed a complex apparatus and the resulting classifications are not universally agreed upon due to the different patterns of the apparatus evolution within the class. Using the most recent reconstructions of the prioniodontid apparatuses a picture of their evolution is obtained. The proposed classification is based on different apparatus styles which persisted as unbroken lineages. The proposed suprageneric classification for the prioniodontids includes the order Prioniodontida Dzik, 1976 with the superfamilies Prioniodontoidea Bassler, 1925 and Balognathoidea Hass, 1959. The new order Polyplacognathida with the family Polyplacognathidae Bergstrom, 1981 and the new family Cahabagnathidae is introduced
Bentonite beds and discontinuity surfaces as correlative tools in the Lower Ordovician carbonates of Baltoscandia
No full textThe Orthoceras Limestone on the East European Platform during the Early to Middle Ordovician is characterized by numerous discontinuity surfaces. The most prominent represent important sequence boundaries. The contemporaneous marginal and basinal deposits are interrupted by several bentonite beds that can be traced laterally onto the paltform, where the ash-beds disappear to be replaced by characteristic discontinuity surfaces. The ash-beds and the lateralli equivalent discontinuity surfaces are correlated using high-resolution biostratigraphy
Lower Ordovician (Billingenian - Kunda) conodont zonation and provinces based on sections from Horns Udde, north Öland, Sweden
No full textThe Hunnebergian to Kunda conodont succession of the lower Ordovician Orthoceras Limestone on northern Öland, Sweden is described. The faunal succession is based on 57563 conodont elements recorded from two representative sections: North of Horns Udde and Horns Udde quarry. The new data allow the recognition and definition of 10 successive interval zones, each characterized by a nominate species and a distinctive conodont association. The interval zones are recommended to substitute the previous assemblage zones in future references to the conodonts of the Öland region. The interval zones are compared with earlier and corresponding zones of the lower Ordovician in neighbouring areas. The interval zones provide an alternative reference to former formally established zones as precise correlation across the East European Platform is possible. The fauna changed from cosmopolitan in Billingen time to provincial in Volkhov time. The fauna assemblages changed from Pandemic forms to temperate water (Precordilleran) faunas and finally were replaced by cold water (Baltic Province) conodonts of the North Atlantic Realm. The Baltic Province persisted throughout the lower Ordovician on the East European Platform. The change of fauna from Pandemic to provincial is connected with sea level changes and a shallowing of the shelf environs. One new multielement genus is recognized: Lundodus; one multielement genus has been revived: Gothodus Lindström, 1955, and two multielement genera are revised: Lenodus Sergeeva, 1963 and Trapezognathus Lindström, 1955. Four new species are named: Parapanderodus quietus, Protopanderodus floridus, Protopanderodus calceatus, and Scolopodus princeps, and 20 species are reported but not formally named because they are of low occurrences but with a known apparatus structure and because the number of specimens avaible was not adequate for their definition
Palaeogeographic Distribution of Arenigian (Lower Ordovician) Conodonts
No full textThis paper presents a review of the Paleogeographic distribution of conodont faunas throughout the early Arenigian. According to their geographical distribution the conodont genera have been dividen into five groups: the pandemic Group, the warm water Group including genera belonging to the Midcontinent Province, the cold water Group including genera of the North Atlantic Province, the temperate water Group, and the warm water China Group characterized by an endemic fauna mainly recorded from China and Korea, and their ocuurences has been examined in the different paleocontinents
Early Ordovician conodonts from Cow Head Peninsula, western Newfoundland.
No full textThis paper presents taxonomical description of latest Tremadocian to Middle Arenigian conodonts recovered from the Ledge-Point of Head Section /Cow Head Group) on the southwestern shore of Cow Head Peninsula, western Newfoundland. 20 samples have been collected yielding about 18.000 conodont elements. 42 genera and 75 species are present. New genera and new species are described. The conodont fauna comprises species both from the Micontinent "Province" and the North-Atlantic "Province". Refinements to the current zonation available for the North Atlantic "Province" on the basis of species of Prioniodus are suggested. Three transgressive-regressive events have been recognized and correlated with the faunal succession. The evolutionary history of Prioniodus and Oepikodus is suggested
Changes in conodont provincialism and biofacies during the lower Ordovician in Oeland, Sweden.
No full textIn the Hunnebergian to Kunda interval (Arenig), the conodont association recorded from Horns Udde (Oelans, Sweden) show a change from cosmopolitan to provincial. After a prominent Precordillera faunal influx in Billingenian, the Vokhov fauna is characterized by taxa typical of the Baltic Province. The change of the conodont fauna is connected with sea level changes and indicates a shallowing of the shelf environment. Sea level fluctuations, within a more general shallowing, are evidenced by changes in the conodont biofacies and supported by Sr and Ca isotope analyses for the interval under consideration
Upper Furongian (Cambrian) conodonts from the Degerhamn quarry road section, southern Oeland, Sweden.
No full textThe Alum Shale Formation exposed at the Degerhamn quarry road section, southern O ̈ land,
Sweden, contains a diversified assemblage of euconodonts, paraconodonts and protoconodonts, the
majority of which have ranges confined to the Furongian Series (Cambrian). The first occurrence (FO) of
the cosmopolitan euconodont species Proconodontus muelleri is recorded in the uppermost part of the
Ctenopyge spectabilis trilobite Zone and the first appearance datum of Cordylodus? andresi is in the upper
part of the Parabolina lobata trilobite Zone. Three new successive paraconodont associations are
introduced: (1) the Furnishina Association, (2) the Prooneotodus Association and (3) the
Westergaardodina Association, which, respectively, correspond to deeper marine, deep marine and
shallow marine conditions. The genus Stenodontus Chen & Gong is revised in multielement taxonomy.
New species formally named are Furnishina holmi and Westergaardodina asinina; Furnishina sp. A and
Furnishina sp. B are described in open nomenclatur
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