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1

A new Lower Coniacian fauna from the Jerzmanice Zdrój region of the North Sudetic Basin, SW Poland

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Chrząstek A.

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tom Vol. 40

33-50

EN

This paper describes and interprets a newly discovered Lower Coniacian (lower Upper Cretaceous) macro- and micro- fossil fauna (vertebrate and invertebrate remains) from sedimentary rocks of the Jerzmanice Zdrój region of the North Sudetic Basin of SW Poland. Several inoceramid bivalve taxa that previously were only known from other parts of the North Sudetic Basin were recovered from light grey, marly sandstones of Early Coniacian age. A fragment of ammonite was also discovered, as was a shark's tooth from the family Cretoxyrhinidae: this may be Cretoxyrhina mantelli Agassiz, 1843, a species not hitherto known from the Lower Coniacian (Emscherian sensu Scupin (1912-13)) of the North Sudetic Basin. Abundant foraminifers were observed in thin sections. The newly discovered inoceramid bivalves - Cremnoceramus deformis erectus Meek, 1877, Cremnoceramus waltersdorfensis waltersdorfensis Andert, 1911 and Inoceramus lusatiae Andert, 1911 - fit into the current biostratigraphic scheme for the region. The inoceramids can all be assigned to the Cremnoceramus deformis erectus Zone, which correlates with the Gavelinella moniliformis foraminiferal Zone and thereby confirms an Early Coniacian age. The Turonian-Coniacian boundary in the North Sudetic Basin can now be placed between the respective inoceramid zones of Inoceramus costellatus Woods, 1912 (actually Mytiloides costellatus Woods, 1912) and Inoceramus schloenbachi Böhm, 1911 (actually Cremnoceramus crassus crassus Petrascheck, 1903). The macrofossils found in the Jerzmanice section suggest that the host sediments were laid down in a Late Cretaceous epicontinental basin, under the North Sudetic Sea, that had deepened during the Early Coniacian. This interpretation agrees with the global bathymetric curve for the Late Cretaceous in Europe.

2

Palaeolatitudinal gradients along the southeastern Palaeo-Pacific margin and the distribution of Early Jurassic bivalves

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Damborenea S. E. , Echevarria J.

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2015

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tom Vol. 13, no. 1

3--16

EN

Presence-absence bivalve species data for each Early Jurassic stage along southeastern South America between 20 and 46°S present-day latitude were processed by a set of analytical methods to analyse the palaeolatitudinal patterns of diversity and distribution. The expected decrease in species diversity towards higher latitudes is punctuated by a consistent local diversity increase between 34 and 42°, especially evident during Pliensbachian and Toarcian times, which may be due to an abrupt change in palaeogeography at that latitude, coinciding with the Curicó direct connection to the open ocean and the establishment of an increased variety of habitats within the extensive Neuquén Basin. The proportions of systematic groups show relative increases towards both higher latitudes (Crassatelloidea, Nuculanoidea, Pectinoidea, Monotoidea, Inoceramoidea) and lower latitudes (Trigonioidea, Pholadomyoidea, Limoidea, Lucinoidea). Epifaunal bivalves were dominant during the Hettangian but by Pliensbachian–Toarcian times they were less common than infaunal ones, while semi-infaunal species had low diversities during the whole Early Jurassic. This study suggests that (a) large scale geographical conditions should be taken into account for the analysis of latitudinal diversity trends among benthonic faunas; and (b) latitudinal trends of some living bivalve lineages may have a longer and more complex history than previously thought.

3

Remarks on Miocene bivalve zonation in the Polish part of the Carpathian Foredeep

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Studencka B.

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tom Vol. 43, Nr 4

467-477

EN

Middle Miocene (Badenian and Sarmatian) bivalve faunas from the Carpathian Foredeep in Poland were analysed in order to determine their potential stratigraphic importance. The study revealed that selected pectinid species are useful to characterize the Badenian substages, but that comparison of pectinid assemblages from Poland and Hungary indicates that subdivision of the Badenian based on pectinids holds true only within individual basins of the Central Paratethys. On the other hand, the strong similarity of the Polish Sarmatian bivalve assemblages to assemblages from other basins of the Fore-Carpathian part as well as from the Euxino-Caspian part of the Paratethyan Province makes the molluscan biozonation of the Eastern Paratethys valid for Poland.

PL

Małże, mimo iż swą wiodącą rolę w stratygrafii miocenu utraciły na rzecz organizmów planktonicznych, wciąż są niezwykle ważne w rozpoziomowaniu osadów powstałych w epikontynentalnych basenach Paratetydy, Przedyskutowano rolę zespołów małżowych w charakteryzowaniu poszczególnych podpięter badenu i sarmatu. Badaniom porównawczym poddano zespoły przegrzebków pochodzące z 5 stanowisk dolnego badenu i 10 stanowisk górnego badenu oraz zespoły małżowe z 5 stanowisk sarmatu polskiej części zapadliska przedkarpackiego. Spośród 5 poziomów zespołów przegrzebków wyróżnionych w osadach miocenu Węgier został stwierdzony tylko poziom Flabellipecten besseri. Diachroniczne pojawianie się przegrzebków i ich ograniczone rozprzestrzenienie wewnątrz Paratetydy Środkowej uniemożliwia wydzielenie w obrębie polskiego badenu dwóch podpoziomów: Pecten revolutus Chlamys elegans i Pecten aduncus-Flabellipecten leythajanus, proponowanych dla badenu Węgier. Zespół przegrzebków z badenu Polski obejmuje 29 gatunków; występowanie 11 gatunków ograniczone jest do dolnego badenu. Dla górnego badenu gatunkami charakterystycznymi są: Aequipecten malvinae, Aequipecten elegans, Flexopecten lilii i Flexopecten scissus. Gatunki z rodzaju Flexopecten wraz z Palliolum bittneri datują najwyższy baden facji basenowej. Datowanie klastycznych osadów sarmatu możliwe jest natomiast dzięki obecności w analizowanych zespołach małżowych gatunków z rodzaju Plicatiforma. W stratygraficznym podziale sarmatu proponowanym przez E. Kojumdziewą i in. (1988) w sarmacie dolnym (wołynie) wyróżniono dwa poziomy współwystępowania: dolny Mactra eichwaldi-Plicatiforma praeplicata pseudoplicata i górny Mactra eichwaldi-Plicatiforma plicara. Skład taksonomiczny zespołów z Bożykowej, Suskrajowic i Śladkowa Małego jest typowy dla poziomu dolnego, podczas gdy obecność gatunku indeksowego Plicatiforma plicata w zespole ze Źrecza jednoznacznie wskazuje na poziom górny. Najmłodsze osady sarmackie datowane na późny wołyn/wczesny bessarab pochodzą z otworu wiertniczego Jamnica S-119 (głęb. 65,0-67,5 m). Brak gatunków indeksowych uniemożliwia dokładne podanie poziomu.

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The late Silurian-Middle Devonian long-term eustatic cycle as a possible control on the global generic diversity dynamics of bivalves and gastropods

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Ruban D. A.

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tom Vol. 19, No. 3

193--200

EN

A long-term eustatic cycle (fall and subsequent rise of the global sea level) embraced the late Silurian-Middle Devonian time interval. Potentially, these sea-level changes could drive global biodiversity. The stratigraphic ranges of 204 bivalve genera and 279 gastropod genera included into the famous Sepkoski database allow reconstructing changes in the total diversity and the number of originations and extinctions of these important groups of marine benthic macro- -invertebrates during this interval. None of the recorded parameters coincided with the long-term global sea-level cycle. It cannot be not excluded, however, that the global sea-level changes did not affect the regions favourable for bivalve and gastropod radiation because of regional tectonic mechanisms; neither can it be excluded that the eustatic control persisted together with many other extrinsic and intrinsic controls. Interestingly, the generic diversity of gastropods increased together with a cooling trend, and vice versa. Additionally, the Ludlow, Eifelian, and Givetian biotic crises affected, probably, both fossil groups under study. There was also a coincidence of the relatively high bivalve generic diversity, initial radiation of gastropods and the entire biota, and the diversification of brachiopods with the Early Devonian global sea-level lowstand, and this may be interpreted as evidence of a certain eustatic control on the marine biodiversity.

5

Bivalves from the Middle Miocene reefs of Poland and Ukraine : A new approach to Badenian/Sarmatian boundary in the Paratethys

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Studencka B. , Jasionowski M.

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tom Vol. 61, no. 1

79-114

EN

The Late Badenian coralline algae-vermetid reefs and the Early Sarmatian serpulid-microbialite reefs distributed widely in the northeastern and eastern borders of the Carpathian Foredeep Basin contain an excellent bivalve record and show how the bivalve faunas reflected the temporary closure of seaways between the Paratethys and the Mediterranean around 13.3 Ma. within the Late Badenian reefs, 116 bivalve species and three bivalve associations are recognized. After a dramatic change of environmental factors, the Early Sarmatian reefs hosted 12 bivalve species, grouped in four associations. These are thought to have been controlled largely by salinity and to represent decreased and/or fluctuating salinity regimes. An integrated approach, using benthic fauna, sedimentological and isotope data, enabled interpretation of the origin of the serpulid-microbialite reefs. The changes in the palaeogeography of the Paratethys and sea-level oscillations around the Badenian/Sarmatian boundary played an important role in the distribution, extinction and radiation of the bivalves. The definitive closure of the extensive seaway connecting the Paratethys with the Mediterranean caused not only severe extinction of the bivalves inhabiting the sandy facies during the Late Badenian but also the sudden evolution and dispersal of a few opportunistic species that were ancestral forms to Sarmatian taxa. The composition of the bivalve assemblages and the ecological requirements of particular species prove the mixo-mesohaline character of the Sarmatian Sea (30-18[per-mille]) and indicate an eastward decrease in salinity.