Cretaceous Material Research Articles

A new neoselachian shark from the marine Early Cretaceous of Southern England

Rare, isolated teeth of Corysodon multicristatus sp. nov. are described from two levels in the Atherfield Clay Formation (Early Aptian, Early Cretaceous) of Atherfield Point on the Isle of Wight, UK. Ten teeth of the new species were recovered from 1095 kg of washed and graded sediment residues. The teeth themselves are very small (around 0.5 mm high) and possess a distinctive crown bearing a tiered series of transverse crests adapted for rasping. Details of the dental architecture of the Atherfield Clay Formation specimens clearly indicate that the Cretaceous material differs significantly from the teeth of the type species for the genus, Corysodon cirinensis, recorded from the Kimmeridgian of northern France and Switzerland. C. multicristatus is the first substantiated record of the genus from the Early Cretaceous, thereby extending the stratigraphic range of the genus from the latest Jurassic, and the geographical range from continental Europe to the UK.

Geodiversity of Las Loras UNESCO Global Geopark: Hydrogeological Significance of Groundwater and Landscape Interaction and Conceptual Model of Functioning

Las Loras UNESCO Global Geopark (UGGp) is geologically diverse, particularly in relation to water-derived features: springs, karst springs, travertine buildings, waterfalls, caves. In this work, the interactions between geology, geomorphology, structures and hydrogeology are analyzed. As a result of this study, a first conceptual model of the hydrogeological functioning at Las Loras UGGp is presented. The most plausible hypothesis is that the system is formed by two superimposed aquifer systems, separated by an aquitard formed by Lower Cretaceous material. The deep lower aquifer formed by the Jurassic limestones only outcrops on the northern and southern edges of the Geopark and in a small arched band to the south of Aguilar de Campoo. It forms a basement subject to intense deformation. The upper aquifer system, formed by outcropping materials from the Upper Cretaceous, is a free aquifer. It is formed by a multilayered aquifer system that is highly compartmentalized, constituting individual moorland and lora units acting as a separate recharge–discharge system. This model explains the base level of the permanent rivers and the abundant springs, important components of the water cycle and representing a contribution to the rich geological heritage of the location.

An overview of ichthyosaurian remains from the Cretaceous of Texas, USA

The clade nominal Ophthalmosauridae encompasses all currently recognized ichthyosaurian taxa from the mid-Cretaceous (Albian–Cenomanian) time interval in North America. These would have inhabited what is today known as the Western Interior Seaway. The remains represent mid to large-sized (up to around 5 m in maximum body length) ichthyosaurians that are mainly based upon isolated teeth and vertebrae, although some partial skeletons have been recovered from both the USA and Canada. Most of these fossils have taxonomic affinities with platypterygiines, such as the ubiquitous ‘form genus’ Platypterygius. This taxon has historically been the default identification for most North American Cretaceous ichthyosaur specimens. However, in comparison with remains from elsewhere, the ichthyosaurian fossils from Texas have been relatively understudied. Here, I review the existing records and present a concise list of all Cretaceous ichthyosaurian material currently held in public museum collections across the state. I have recognized 11 Cretaceous ichthyosaurian occurrences from Texas, including an indeterminate tooth, numerous vertebral centra, and some fragmentary skeletal remains attributable to Platypterygius. Ichthyosaurians therefore demonstrably occupied the Cretaceous epeiric seas of Texas from at least the Albian to middle Cenomanian, a distribution that traverses both the western and eastern coastlines of the Western Interior Seaway during its early phase of southern epicontinental incursion.

Roveacrinida (Crinoidea, Articulata) from the upper Maastrichtian Peedee Formation (upper Cretaceous) of North Carolina, USA – The last pelagic microcrinoids

Microcrinoids belonging to the Order Roveacrinida are described from the Late Maastrichtian Peedee Formation of North Carolina. Five species are present; Applinocrinus texanus Peck, 1973, Lucernacrinus multispinosus Gale, sp. nov., Birgenelocrinus degraafi Jagt, 1999, B. jagti Gale, sp. nov. and Peedeecrinus sadorfi Gale, gen. et sp. nov. Two of these species (A. texanus, B. degraafi) and close relatives of two others (Lucernacrinus, Birgenelocrinus jagti) are known from the upper Maastrichtian (upper Maastricht Formation) of the Netherlands and northeastern Belgium, indicating that the Roveacrinida were flourishing and widespread up to the end of the Cretaceous. It is concluded that Paleogene and Neogene records of Roveacrinidae represent contamination of samples by Cretaceous (Turonian) material.

The Grain de mil flint, a key resource from south-western France during the Palaeolithic: Characterization and determination criteria in archeological contexts

Land use patterns are typically used to describe Palaeolithic hunter-gatherer nomadic groups. Due to the methodological development of petroarchaeology, in south-western France in particular, this region is one of the best documented European areas in terms of siliceous resources. But one major unknown still needs to be addressed: the characterization and origin of the so-called “Grain de mil” flint, a common raw material that has never been properly described and sourced even though it has been identified in archeological contexts over a very extensive area. In order to address this issue, we first approach the question of the lithic raw material analytical method: the sedimentary petrographic description remains the best approach to directly include petrological data in a petro-techno-economical study. We then present the results of the Grain de mil study: this material is typical of Charente-Maritime as its formation is linked to the Jonzac anticline. It forms a flint group comprising two types (Jonzac and Saintes), mostly differing with regard to outcrop location, and nodule size and shape. In archeological contexts, criteria observable with a binocular microscope are sufficient to distinguish the Grain de mil from other north Aquitaine Cretaceous materials with abundant grains, particularly regarding their organization and pattern, and the absence of quartz grains.

Early evolution of the family Siderastraeidae (Scleractinia; Cretaceous-extant)

Critical review of Mesozoic and Paleogene fossil type material and morphological comparison with the type genus Siderastrea of the family Siderastraeidae propose that the earliest members of the family date from the Late Valanginian (Early Cretaceous) and gained diversity during the Early Cretaceous. The most common member is the new genus Eosiderastrea, which encompasses all Cretaceous material that was formerly assigned to the extant coral genus Diploastrea. The new genus is characterised by an astreoid, rarely plocoid or cerioid calicular arrangement, and a sub-regular septal symmetry representing hexameral, heptameral, octameral and decameral symmetries. The septal blades are made of medium-large trabeculae. Synapticulae are present. Eighteen Cretaceous species are assigned to the new genus. The genus Eosiderastrea occurs worldwide and ranges from the Late Valanginian to the Santonian. Cretaceous material formerly assigned to Siderofungia is assigned to the new genus Palaeosiderofungia, which is characterised by a thamnasterioid calicular arrangement with calices predominantly arranged in rows and an extended coenosteum. The septal blades are made of medium-large trabeculae; synapticulae are present. There is no septal symmetry. Apart from the type species Thamnasteria exigua, another four unnamed species are known. The new genus occurs only in the Boreal and Central to Western Tethys and ranges from the Aptian to Santonian. The occurrence of the extant Siderastrea in the Cretaceous cannot be ruled out. Isolated finds are reported from the Aptian onwards.

U–Pb dating of detrital zircons from Andros, Greece: constraints for the time of sediment accumulation in the northern part of the Cycladic blueschist belt

The Attic–Cycladic Crystalline Belt in the central Aegean region represents a major tectono‐stratigraphic unit of the Hellenides. The essential geological, magmatic and tectono‐metamorphic features are well documented. Unresolved questions concern the time of sediment accumulation and litho‐ and/or tectono‐stratigraphic relationships across the study area. In order to address this issue we have studied siliciclastic metasedimentary rocks from Andros Island, northern Cyclades. The sampling strategy aimed at covering the complete age range recorded by the Andros metamorphic succession. Detrital zircon U–Pb dating of nine samples indicates maximum depositional ages of c. 260 Ma for the topmost part of the metamorphic succession and of c. 160–140 Ma for rock sequences below a prominent serpentinite belt that is interpreted to outline a major tectonic contact. These age constraints are in accordance with interpretations suggesting that the metamorphic rocks of Andros represent different tectonic subunits (Makrotantalon Unit and Lower Unit) that are separated by a thrust fault. Modification of the internal structure of the Lower Unit by tectonic stacking can currently not be ascertained. The new data for the Lower Unit corroborate the importance of Late Jurassic–Early Cretaceous sediment accumulation for the larger study area. In contrast to some of the neighbouring islands, no evidence for transfer of Late Cretaceous (c. 80 Ma) material into the Andros sedimentary environment was found. The most striking feature of the zircon populations of the Lower Unit is a remarkable age cluster at 250–200 Ma that documents the importance of Triassic igneous sediment sources. Copyright © 2015 John Wiley & Sons, Ltd.

Megolisthaerus, interpreted as staphylinine rove beetle (Coleoptera: Staphylinidae) based on new Early Cretaceous material from China

Megolisthaerus minor sp. nov., a new rove beetle belonging to an unusual extinct genus Megolisthaerus Solodovnikov and Yue is described and figured on the basis of an exceptionally well-preserved specimen from the Lower Cretaceous Yixian Formation at Huangbanjigou, Liaoning Province, China. Based on the better preservation of additional morphological characters in our new specimen (e.g., elongate antennomere 1, presence of distinct infraorbital ridges, 5-segmented pro- and mesotarsi, and abdominal intersegmental membranes with fine and less rectangular sclerites), we herein suggest Megolisthaerus belongs to the Recent subfamily Staphylininae (tribe unknown), rather than a member of, or closely related to, the subfamilies Olisthaerinae and Phloeocharinae of the Tachyporine group of subfamilies. A revised diagnosis of Megolisthaerus is given, and the systematic position of Megolisthaerus within subfamily Staphylininae is discussed.

Production of ceramic bodies from Tunisian Cretaceous clays

AbstractThe aim of this research was to assess the potential application of the Late Cretaceous levels as raw material for the production of ceramic tiles. Mineralogical, chemical and grain size distribution studies were carried out on four clays sampled at different sites in the Tunisian Central Atlas. Clays are mainly composed of phyllosilicates, usually illite and kaolinite. Quartz, feldspars and dolomite were also detected.Tiles were prepared by pressing clay bodies at 250 bar and then firing at different temperatures following industrial conditions as closely as possible. Thermal analysis showed the influence of mineralogical composition and grain size distribution on the material behaviour during firing. The physical properties of fired tiles were obtained from specific tests in accordance with international standards (ISO), i.e. the firing shrinkage, water absorption, apparent density and flexural strength. The development of physical properties indicates an optimal firing range between 1050–1150°C. Results demonstrate the potential of Late Cretaceous materials as raw materials for the production of ceramic tiles.

Foraminifera collections in the Senckenberg Naturmuseum, Frankfurt-am-Main

The collections of Foraminifera in the Senckenberg Naturmusem are extensive and date back to the mid-nineteenth century. The oldest material is the collection of Professor O. Boettger which contains specimens from Reuss (1863). Other notable parts of the collection include the Jurassic and Cretaceous material of Adolf Franke (e.g. 1936; inventor of the Franke-slide), Franz Hecht (e.g. 1938), Helmut Bartenstein and Erich Brand (e.g. Bartenstein, 1938; Bartenstein & Brand, 1937, 1938). Further information can be found in Zilch (1939), Triebel (1967), Bartenstein & Brand (1981) and Schroeder (1989). Foraminifera are catalogued under the prefix SMF XXVII. The …

Evaluation of Diagenetic Effect using Fourier Transform Infrared Spectroscopy: Possibility of Application to Enamel of Cretaceous Marine Reptiles

The isotopic composition of fossil animal substances has performed an important role as an indicator of ecological signature for Cenozoic mammals over the last few decades. Recently, isotopic analysis of Cretaceous vertebrates has been used to reconstruct paleoecology, but the effect of diagenesis on such old materials has not been well understood. An evaluation of the effect of diagenesis on enamel from Cretaceous vertebrates is necessary to determine the reliability of isotopic paleoecology. I evaluated the extent of diagenetic effect on enamel from Cretaceous mosasaurs by using Fourier Transform Infrared Spectroscopy (FT-IR). Clear diagenetic alteration was not found in the enamel, showing Cretaceous material may retain pristine isotopic information.

A revision of enantiornithine (Aves: Ornithothoraces) skull morphology

Enantiornithines are the most speciose avian clade in the Mesozoic, with a fossil record that nearly spans the Cretaceous; however, with less than half of known taxa preserving skull material, our understanding of their cranial morphology remains incomplete. Here we present a comprehensive overview of the current knowledge of enantiornithine skull anatomy and discuss the range of morphologies known for each of the main cranial elements. The typical enantiornithine skull retains numerous ancestral features such as the absence of fusion among bones, the presence of a postorbital bone, a primitive quadrate with a single headed otic process, an unforked dentary, and teeth. The postorbital in at least one taxon is unreduced, suggesting the existence of a complete infratemporal fenestra and thus an unmodified diapsid skull as in confuciusornithids. The rostrum is well known and shows considerable variation, typical of theropods; however, in terms of rostral proportions, enantiornithines are extremely limited within the modern avian spectrum. Although Late Cretaceous skull material is extremely fragmentary, when compared to Early Cretaceous material it reveals a trend towards more specialized morphologies in younger taxa. The foramen magnum in all taxa points caudally, indicating that the ‘flexed’ type skull morphology may not have evolved in this group. Enantiornithine teeth show considerable diversity in numbers, size, morphology and placement, ranging from taxa with large teeth found throughout the jaws to taxa with small, rostrally restricted teeth, to the fully edentulous. Despite limited preservation of skull material, a number of trophic specializations can be deduced from the range of preserved morphologies, further hinting at the morphological and ecological diversity of the Cretaceous Enantiornithes.

The Australian Cretaceous ichthyosaur Platypterygius australis: a description and review of postcranial remains

ABSTRACT Australian Cretaceous ichthyosaur material is amongst the most complete in the world. This study describes postcranial remains referred to the upper Albian species Platypterygius australis, including the first record of pelvic and hind limb elements for this taxon. A combination of phylogenetically significant traits such as lack of fusion between the atlas-axis complex and third cervical centrum, the presence of three distal facets on both the humerus/femur for accommodation of the anterior zeugopodial elements plus the radius/tibia and ulna/fibula, concave preaxial accessory facet surfaces on both the humerus and the femur, and complete fusion of the ischiopubis with closure of the obturator foramen, are considered diagnostic for the species and (in conjunction with other previously identified cranial/postcranial features) may serve to distinguish P. australis from the other paleogeographically disparate Platypterygius spp.

Reworked calcareous nannofossils as ocean dynamic tracers: The Guadiana shelf case study (SW Iberia)

For most micropalaeontological studies the presence of reworked specimens is usually considered as a disturbing factor where palaeoenvironmental or biostratigraphic interpretations are to be made. However, reworking of microfossils such as calcareous nannofossils can be used as an additional parameter in routine micropalaeontological work, providing useful information on erosion-transport processes acting on silty-clay sized particles deriving from areas surrounding the sedimentary basin under study. Most of the reworked calcareous nannofossils found in the Guadiana estuary water column (September 2001), adjacent shelf surface sediments, and a slope section of the Gulf of Cadiz were mainly of Upper Cretaceous age (Campanian to Maastrichtian), being dominated by Biscutum spp., Cribrosphaerella ehrenbergii, Prediscosphaera cretacea and Watznaueria barnesae. Since there are no Upper Cretaceous outcrops in the Guadiana's hydrographic basin or southern Portugal, the source of this material must be located elsewhere. Matrix breccias from mud volcanoes discovered in deeper water southern Portuguese and western Moroccan margins of the Gulf of Cadiz during the TTR-10 cruise in July/August 2000, as well as silty-clay sediments from its slopes, revealed similar calcareous nannofossil assemblages as those found on the Algarve continental shelf and inside the Guadiana's estuary. This may indicate that most of the reworked nannofossils have their origin in deepwater areas of the Gulf of Cadiz. The good preservation of most of the reworked Cretaceous nannofossils suggest that, shortly after resuspension, swift transport occurred from the source area to the coastal region of the Guadiana's river mouth, implicating a northward change in the deep Mediterranean water direction within the Gulf of Cadiz, which reaches the upper southwest Iberia slope. The Mediterranean Outflow is, therefore, the major mechanism accountable for transporting Upper Cretaceous material to the southwest Iberian margin and the Atlantic inflow, together with longitudinal coastal currents, is the probable responsible for carrying and spreading eastward these reworked silty-clay sized particles over the Portuguese and Spanish continental shelf. This case study is a clear example of the potential importance of calcareous nannofossils as ocean dynamic tracers for particles within the silty-clay fraction.

Use of mine spoils from Teruel coal mining district (NE, Spain)

Coal mine restoration projects increase public perception of mining companies. Spain has relatively few examples of completed opencast mine rehabilitation projects. This study seeks to obtain the use of mine spoils from coal mines in Teruel. The studied mine spoils may be used as raw material for the Spanish ceramic industry, located in the provinces of Castellon, Valencia and Teruel. This study specifically discusses the mineralogical and geochemical characteristics of the Lower Cretaceous materials from coal deposits in Estercuel basin, around Teruel and Castellon in Spain. These provinces have a large ceramic industry. A characterization of mine spoils from coal deposits has been carried out. This characterization is based on the data of both mineral and chemical analysis. The mineralogical characterization was complemented with SEM/EDAX. The study of the chemical composition allows the evaluation of the applicability of the studied mine spoils to the following industries: refractory, fine clay, red clay for pavement and coating, and heavy clay. The clay used for refractory industry has the highest compositional demand. The positive results obtained on this set of preliminary tests lead us to envisage new research programs, focusing on testing these mine spoils on a semi-industrial scale.

Infructescences from the Cerro del Pueblo Formation (Late Campanian), Coahuila, and El Cien Formation (Oligocene‐Miocene), Baja California Sur, Mexico

Fruits and infructescences of the Cerro del Pueblo and El Cien Formations, Coahuila and Baja California Sur, Mexico, respectively, allow detailed description and comparison of reproductive structures of plants that grew from the Late Cretaceous at least up to the Miocene. Infructescences collected in the Rincón Colorado and Presa San Antonio localities resemble those of some members of Alismatales; they share multiple or aggregate infructescences, with sessile, unilocular, operculate berrylike fruits, that are free from one another in their distal zones and contain a single orthotropous ovule. Nevertheless, they have other characteristics not found in either fossil or extant infructescences, limiting this resemblance. These features include the development of a distal seed crown by integumentary projection, a fruit operculum inserted into the seed crown, and a channel running through the mesocarp from the exposed operculum surface to the proximal end of the fruit. The presence of sclerotized layers in the seed suggests that the reproductive organs are mature. Differences in number of fruits per infructescence, seed form, number of integumentary layers, and cell sizes in the seed and fruit suggest that two related species are represented among the ca. 1283 known infructescences. This suggests that during the Cretaceous diversity within the order was important. The only infructescence collected from the Oligocene‐Miocene El Cien Formation has a morphology that closely resembles that of the Cretaceous material. Even the polyhedric shape of the exocarp cells of the Baja California Sur material is similar to that of the Coahuila material. Unfortunately, this material was not cut for further comparison, but the available data suggest that this lineage lived in northern Mexico until at least the Oligocene‐Miocene.

The deep crust beneath island arcs: Inherited zircons reveal a Gondwana continental fragment beneath East Java, Indonesia

Inherited zircons in Cenozoic sedimentary and igneous rocks of East Java range in age from Archean to Cenozoic. The distribution of zircons reveals two different basement types at depth. The igneous rocks of the Early Cenozoic arc, found along the southeast coast, contain only Archean to Cambrian zircons. In contrast, clastic rocks of north and west of East Java contain Cretaceous zircons, which are not found in the arc rocks to the south. The presence of Cretaceous zircons supports previous interpretations that much of East Java is underlain by arc and ophiolitic rocks, accreted to the Southeast Asian margin during Cretaceous subduction. However, such accreted material cannot account for the older zircons. The age populations of Archean to Cambrian zircons in the arc rocks are similar to Gondwana crust. We interpret the East Java Early Cenozoic arc to be underlain by a continental fragment of Gondwana origin and not Cretaceous material as previously suggested. Melts rising through the crust, feeding the Early Cenozoic arc, picked up the ancient zircons through assimilation or partial melting. We suggest a Western Australian origin for the fragment, which rifted from Australia during the Mesozoic and collided with Southeast Asia, resulting in the termination of Cretaceous subduction. Continental crust was therefore present at depth beneath the arc in south Java when Cenozoic subduction began in the Eocene.

Evidence for a second species of the ichthyosaur Platypterygius in North America: a new record from the Loon River Formation (Lower Cretaceous) of northwestern Canada

To date, all Cretaceous ichthyosaur material from North America has been referred to the species Platypterygius americanus. This species is generally identified based on skull and paddle morphology, but all non-diagnostic material from North America has been assigned to this species. A new Lower Cretaceous ichthyosaur from the Loon River Formation at Hay River, Northwest Territories, Canada, is described here. The specimen in question consists of the anterior portion of a large ichthyosaur, of which only the pectoral girdle is well preserved. It is assignable to Platypterygius, but is inconsistent with P. americanus based on paddle morphology. It shares most similarities with European and Australian species; unfortunately, it cannot be definitively assigned to any one taxon because of poor preservation of the skull. This specimen increases our knowledge of the diversity of North American Cretaceous ichthyosaurs, and suggests that the Cretaceous Western Interior Seaway was capable of sustaining a large taxonomic diversity of these marine reptiles, similar to the high numbers of Platypterygius species known from Europe.

Pátek, Levousy a Chlumčany – významné fosiliferní středopleistocénní lokality na pravém břehu Ohře mezi Louny a Libochovicemi [Pátek, Levousy and Chlumčany – important mid-pleistocene localities on the right bank of the Ohře River between Louny and Libochovice

Due to a complete predominance of non-calcareous fluvial sediments in the Czech Republic, any find of fossil malacofauna is always considered as rare. The present work describes three localities in the Ohře river area, which contain, especially in the case of the Pátek locality, very abundant mid-Pleistocene malacofaunas. They were mainly collected in the floodplain fine-grained loam and back swamp deposits but also in sandy gravels. The molluscan thanatocenoses from localities near the Pátek village indicate the interglacial maximum (with up to 25 forest species s.l.), which developed directly on a 30 m thick river terrace dating back to the period, during which the Ohře river established its present-day easterly course. The fossil molluscs from the Levousy locality come from floodplain loam deposits as well as from the underlying sandy terrace gravels. The species distribution, nevertheless, indicates only a transitional glacial-interglacial period. The somewhat higher morphologic position of the locality, as well as that of another section at Chlumčany, and complete predominance of local late Cretaceous material indicates that the Ohře river did not flow to the east yet during the accumulation of the floodplain deposits with molluscs, but still to the north, towards Bílina. The terrestrial malacofauna from the Chlumčany section came from floodplain marls, particularly from sandy tufa deposits in the alluvium, which contains no forest-biotope elements, but the presence of the species Columella columella – distinct representative of our „coldest“ loess deposits – is an absolute surprise, since the peak of production of the sandy tufa deposits has always been associated with climate optima of the interglacials and of the Holocene.Therefore, the described malacofaunas come from a boundary period, during which the Ohře river did not use its present-day valley (Levousy and Clumčany) yet. Then, from the oldest time span, it took up for the first time its eastward course. Stratigraphy of the localities cannot be determined with a reasonable certainty in regard to the current controversial situation in Pleistocene chronology both in the northern foothills of the Alps and in the area of the „classic“ localities belonging to the continental ice-sheet region in northern Germany (Kovanda 2005a). Altogether 12 mid-Pleistocene species of small mammals were found in thanaotocoenoses at localities Pátek and Levousy. Ostracod assemblages analysis was also undertaken (11 species in 8 samples were determined)

Pátek, Levousy a Chlumčany – významné fosiliferní středopleistocénní lokality na pravém břehu Ohře mezi Louny a Libochovicemi [Pátek, Levousy and Chlumčany – important mid-pleistocene localities on the right bank of the Ohře River between Louny and Libochovice

Due to a complete predominance of non-calcareous fluvial sediments in the Czech Republic, any find of fossil malacofauna is always considered as rare. The present work describes three localities in the Ohře river area, which contain, especially in the case of the Pátek locality, very abundant mid-Pleistocene malacofaunas. They were mainly collected in the floodplain fine-grained loam and back swamp deposits but also in sandy gravels. The molluscan thanatocenoses from localities near the Pátek village indicate the interglacial maximum (with up to 25 forest species s.l.), which developed directly on a 30 m thick river terrace dating back to the period, during which the Ohře river established its present-day easterly course. The fossil molluscs from the Levousy locality come from floodplain loam deposits as well as from the underlying sandy terrace gravels. The species distribution, nevertheless, indicates only a transitional glacial-interglacial period. The somewhat higher morphologic position of the locality, as well as that of another section at Chlumčany, and complete predominance of local late Cretaceous material indicates that the Ohře river did not flow to the east yet during the accumulation of the floodplain deposits with molluscs, but still to the north, towards Bílina. The terrestrial malacofauna from the Chlumčany section came from floodplain marls, particularly from sandy tufa deposits in the alluvium, which contains no forest-biotope elements, but the presence of the species Columella columella – distinct representative of our „coldest“ loess deposits – is an absolute surprise, since the peak of production of the sandy tufa deposits has always been associated with climate optima of the interglacials and of the Holocene.Therefore, the described malacofaunas come from a boundary period, during which the Ohře river did not use its present-day valley (Levousy and Clumčany) yet. Then, from the oldest time span, it took up for the first time its eastward course. Stratigraphy of the localities cannot be determined with a reasonable certainty in regard to the current controversial situation in Pleistocene chronology both in the northern foothills of the Alps and in the area of the „classic“ localities belonging to the continental ice-sheet region in northern Germany (Kovanda 2005a). Altogether 12 mid-Pleistocene species of small mammals were found in thanaotocoenoses at localities Pátek and Levousy. Ostracod assemblages analysis was also undertaken (11 species in 8 samples were determined)