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Three ichnospecies of dendritic borings (Clionolithes cf. cervicornis, C. isp. A, and C. isp. B) were observed in abundant brachiopod shells in the Třebotov Formation (lowermost Eifelian, zone Polygnathus partitus) in two Prague... more
Three ichnospecies of dendritic borings (Clionolithes cf. cervicornis, C. isp. A, and C. isp. B) were observed in abundant brachiopod shells in the Třebotov Formation (lowermost Eifelian, zone Polygnathus partitus) in two Prague localities (Praha-Holyně, “V rokli”, and Praha-Barrandov, street “K Barrandovu”). Borings are generally small-sized, of about 1 mm, but they can reach up to 4 mm. Borings are preserved inside thick translucent walls of brachiopods smooth shells (Trigonatrypa holynensis, Xenomartinia monoseptoides and Clorinda sp.). Borings are very frequent (almost in all examined shells), but never pass through a whole wall thickness of a brachiopod. Two or even more borings, commonly of a different type, are preserved on an individual shell. Both valves of articulated specimen may be bored, while the shell interior is devoid of borings neither shows any response to the boring activity such as uneven internal biomineralization. Majority of tunnels bores inside the shell wall, and the borings are opened by small irregular central pit. As more than a half of examined shells were infected, bioerosion likely had a negative impact on the shell preservation. Our study shows that the brachiopod infestation was selective. Only thick calcitic shells were bored, while thinner shells or exopunctate brachiopods (Holynatrypa, Peridalejina, Prokopia) were not a target of the borers. Similarly, crinoid and other echinoderm ossicles do not show any signs of a boring. A different dendritic boring referred to as Clionolithes radicans was observed on a shell of brachiopod coming from the Acanthopyge Limestone (Choteč Formation, Eifelian) from Zadní Kobyla locality near Koněprusy. The stellate trace is substantially larger (4.3 mm × 2.8 mm) than borings from the Třebotov Limestone, with deep and externally open canals. Borings from the Třebotov Limestone come from so-called “white beds”. These soft beds originated by weathering of a hard limestone, leaving loose generally small bioskeletal remains of echinoderms, gastropods, brachiopods, ostracods, dacryoconarids and other invertebrate groups. Dacryoconarid shells and crinoid ossicles dominate. The life assemblage occupied a deeper weakly hypoxic perireef environment below the fotic zone. The dendritic boring from the Acanthopyge Limestone comes from a completely different environment. Associated diverse and generally large brachiopods, fragmented fenestrate bryozoans and abraded tabulate and rugose corals (including Calceola sandalina) indicate a shallow-water highenergy reef environment. This is the first report of dendritic borings from the Eifelian of the Prague Basin. It confirms not only so far unknown presence of their borers in the area, but also reveals that their activity can be observed in the weakly lithified Devonian limestones in the area.
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Diminutive crinoid holdfasts and cemented tests of the foraminifers Psammosphaera and Tolypammina were observed on coarse bioclasts in weathered limestones of the Daleje-Třebotov Formation. Specimens were obtained in 1984 by washing so... more
Diminutive crinoid holdfasts and cemented tests of the foraminifers Psammosphaera and Tolypammina were observed on coarse bioclasts in weathered limestones of the Daleje-Třebotov Formation. Specimens were obtained in 1984 by washing so called “white beds” at a temporary locality in Praha- Barrandov. A few millimeter sized bioclasts with epibionts were freed from hard limestone beds of the Třebotov Limestone near the Lower/Middle Devonian boundary by long-term weathering. Many of the crinoid holdfasts attached to pluricolumnals provoked a stereomic response of the host crinoid. Also the growth orientation of the crinoid epibiont is not random and indicates some crinoid-epibiont to crinoidhost interaction. Reaction of host stereome and non-random stem orientation offer direct evidence of epibiont larval settlement and subsequent growth on the stem of a living crinoid host. The extensive growth of the host stereome ended by partial to total engulfing of the epibiont holdfast. This indi...
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Research Interests: Evolutionary Biology, Geology, Paleontology, Ecology, Devonian, and 3 moreOrdovician, Paleozoic, and Facies
The lower Paleozoic succession of central Europe exposed in the Bohemian Massif is a classic area of geology with a long-standing tradition of research dating back to the eighteenth century. The Ordovician rocks form parts of sections in... more
The lower Paleozoic succession of central Europe exposed in the Bohemian Massif is a classic area of geology with a long-standing tradition of research dating back to the eighteenth century. The Ordovician rocks form parts of sections in several units that sit on the Cadomian basement. These sedimentary and volcano-sedimentary fills of partial depressions in the basement are relics of the system of rift basins in the Gondwanan margin reflecting the rifting of the Rheic Ocean. The Ordovician sections are related to the subsidence period during the extensional regime accompanied by volcanism. They are underlain by Neoproterozoic or Cambrian rocks and continue up usually without breaks. After closure of the Rheic Ocean owing to the Gondwana–Laurussia collision, the Ordovician successions were incorporated into the Variscan Orogen belt and preserved in denudation relics such as the Bohemian Massif and its units. Ordovician strata with Gondwanan shelf affinities can be traced along the V...
Research Interests: Earth Sciences, Geology, Paleontology, Gondwana, Ordovician, and 4 moreRIFT, Paleozoic, Basement, and Massif
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The vertebrate faunas in limestone samples of the Early and Middle Devonian ages (Pragian, early Emsian, late Emsian, and latest Eifelian) which were collected from five localities in the Barrandian area, Bohemia, include scales,... more
The vertebrate faunas in limestone samples of the Early and Middle Devonian ages (Pragian, early Emsian, late Emsian, and latest Eifelian) which were collected from five localities in the Barrandian area, Bohemia, include scales, tesserae, bones, and teeth of acanthodians, placoderms, chondrichthyans, and sarcopterygians. Although the vertebrate remains are not abundant the assemblages are significant in being dominated by particular taxa. Apart from undetermined microremains the genera Cheiracanthoides, Laliacanthus, Nostolepis, and Tassiliodus were determined.
Research Interests: Evolutionary Biology, Geology, Paleontology, Czech, Devonian, and 3 moreFauna, Vertebrate, and Taxon
Brachiopod etching trace Podichnus, typically with centrifugally arranged clusters of holes or slits, has hitherto been known only in calcium carbonate substrates. The similar etching trace is newly described on calcium phosphate... more
Brachiopod etching trace Podichnus, typically with centrifugally arranged clusters of holes or slits, has hitherto been known only in calcium carbonate substrates. The similar etching trace is newly described on calcium phosphate substrate. The trace Podichnus isp. in a wall of a phosphatic byronid test was observed in the lower Devonian Vinařice Limestone (Pragian) in the Koněprusy area of the Prague Basin in the Barrandian area, the Czech Republic. The trace is smaller that majority of described species of this fixichnia, and displays a smooth central disc surrounded by two circlets of holes or pits. Some holes penetrate through wall of byronid test without any biotic response of a byronid. The maker of Podichnus isp. is uknown but among the associated fossils are eligible candidates including rhynchonellids, orthids and terebratulids. It is rare direct evidence of etching activity of the pedicle in the Lower Palaeozoic and the first finding of Podichnus in the Devonian in the Pra...
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In Mokra the Tournaisian-Visean boundary falls within a sequence of alternating shales and thin-bedded calciturbidites. The tectonically complicated sequence contains a very rich fauna of foraminifers, conodonts, trilobites and... more
In Mokra the Tournaisian-Visean boundary falls within a sequence of alternating shales and thin-bedded calciturbidites. The tectonically complicated sequence contains a very rich fauna of foraminifers, conodonts, trilobites and brachiopods and therefore represents a key section for the calibration of the Tournaisian-Visean boundary interval. In conodont fauna all important guides of the latest Tournaisian have been encountered. The diverse trilobite association correlates well with the Erdbach Limestone of the Rheinische Schiefergebirge. The brachiopod fauna is remarkably diversified. Two discrete but subsequently mixed brachiopod associations can be tentatively differentiated. The first prevailing association is probably sub-authothonnous, of deep-water origin and comprises large smooth rhynchonellids similar to Ilopsyrhynchus, the small chonetoid Rugosochonetes sp. and a rhipidomellid Aulacella sp. These taxa are commonly complete (mostly deformed), with valves attached; a minute ...
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Research Interests: Geology, Paleontology, Stratigraphy, Brachiopoda, Pyrenees, and 3 moreDevonian, Pragian, and Lochkovian
A new discinoid brachiopod Gigadiscina gen. nov., with the type species G. lessardi sp. nov., is described from the Lower Devonian (Siegenian) of the Tamesna Basin (South Ahaggar Massif, South Algeria). It is characterised by large size... more
A new discinoid brachiopod Gigadiscina gen. nov., with the type species G. lessardi sp. nov., is described from the Lower Devonian (Siegenian) of the Tamesna Basin (South Ahaggar Massif, South Algeria). It is characterised by large size and convexo−planar profile of the shell, with a subcentral pedicle foramen. Micro−ornament is typically discinoid, with small cir− cular pits in radial rows on the post−larval shell surface. Related species of Malvinokaffric Realm origin from South Africa, Falkland Islands, Antarctica, South America, and Libya are reviewed, including the poorly known Discina anomala from the Lower Devonian of Germany. The giant size and convexo−planar shells of these discinoids, remarkably similar to recent lim− pets, are interpreted as adaptation to a habitat in proximity of sandy and gravel beaches in a high−energy environment. Most likely, the conical dorsal valve suppressed drag in turbulent waters, whereas fixation of shell by large, sucker−like pedicle eliminat...
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The article presents the result of research aimed to presentation of cephalopods in text-books and children’s encyclopedias written in Czech language. The result indicates, that Common cuttlefish (Sepia officinalis) and Common octopus... more
The article presents the result of research aimed to presentation of cephalopods in text-books and children’s encyclopedias written in Czech language. The result indicates, that Common cuttlefish (Sepia officinalis) and Common octopus (Octopus vulgaris) are the most frequent examples of cephalopods in text-books despite the date of print. Chambered nautilus (Nautilus pompilius) is the third commonly displayed species. Other cephalopds are rarely presented, but some books illustrated unique and peculiar deep-ocean species. The shift from detailed information about the species, including its economical significance and practical usage presented in older text-books to species presented as a general model of cephalopod animal with particular anatomy and morphology in modern text-books is obvious.
Small fragments of phosphatic cuticle have been observed in dark limestone of the early Eifelian age (Choteč Formation) in the interval of the Basal Choteč Event. The cuticle is two-layered, primarily folded, with a chamber between outer... more
Small fragments of phosphatic cuticle have been observed in dark limestone of the early Eifelian age (Choteč Formation) in the interval of the Basal Choteč Event. The cuticle is two-layered, primarily folded, with a chamber between outer and inner walls. Fragments likely represent small cuticle pieces from the margins of the carapace. The exterior of the cuticle is nearly smooth bearing irregular network of wrinkled polygons or shallow pits. Low conical mound-like to high thorn-like spines with annular structure extend from both outer and inner surface of cuticle. Wrinkled and folded bases of these spines indicate moderate flexibility of cuticle. Spines are hollow, the higher ones often with apical opening. The inner surface of carapace carries smaller spines or is nearly smooth. Chamber walls inside the cara-pace are with folds and other structures supporting stiffness of the cuticle. The internal walls of the cuticle are covered by polygonal bumps. These uniformly sized and shaped...
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The lingulate brachiopod Schizocrania (Trematidae, Discinoidea) is reviewed. Ptychopeltis is definitively synonymized with Schizocrania, because new data indicate that convexity of the shell, profile of the anterior margin commissure,... more
The lingulate brachiopod Schizocrania (Trematidae, Discinoidea) is reviewed. Ptychopeltis is definitively synonymized with Schizocrania, because new data indicate that convexity of the shell, profile of the anterior margin commissure, density of the dorsal valve costellation, ornamentation of the ventral valve and shape of the pedicle notch are worthless for separation of these genera. Four Ordovician species of Schizocrania are reported from the Barrandian area: S. multistriata (Darriwilian), S. hornyi (Sandbian), S. incola (Sandbian) and the new species S. equestra sp. nov. (Katian). Occurrence of Schizocrania striata is confirmed for the first time around the S/D boundary in the Barrandian area. Schizocrania has a wide geographic range with mid-Ordovician to early Devonian occurrences in Laurentia, Avalonia, West Gondwana and the Silurian occurrence in Baltica. Schizocrania was the earliest lingulate brachiopod adhering to floating objects in an open sea (both living cephalopods ...
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The Angosto de Lampazar, a classic locality for the study of lower Paleozoic successions in the Cordillera Oriental, NW Argentina, has yielded a late Cambrian relatively diverse, lingulate brachiopod fauna. Sandy lenses with calcareous... more
The Angosto de Lampazar, a classic locality for the study of lower Paleozoic successions in the Cordillera Oriental, NW Argentina, has yielded a late Cambrian relatively diverse, lingulate brachiopod fauna. Sandy lenses with calcareous cement from the uppermost levels of the Lampazar Formation have yielded abundant remains of articulate and phosphatic brachiopods. Among the latter, the new speciesEurytreta harringtoniMergl and Herrera,Lingulella?melonicaMergl and Herrera,Libecoviella lenticularisMergl and Herrera, andSchizambon cardonalisMergl and Herrera, as well as the new genus and speciesSaltaia lampazarensisMergl and Herrera are formally introduced. Trilobites and conodonts from the same horizons characterize theCordylodus proavusZone, allowing a correlation with Stage 10 of the Furongian Series. Although the information on lingulate brachiopods from theC.proavusZone is scarce across the world, the composition of the studied association displays a relationship with coeval and s...
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Problematic phosphatic sclerites Eurytholia are reported for the first time from the Middle Devonian. Unequivocal sclerites were observed in limestones of Emsian to late Eifelian age in six localities of the Barrandian area of the Central... more
Problematic phosphatic sclerites Eurytholia are reported for the first time from the Middle Devonian. Unequivocal sclerites were observed in limestones of Emsian to late Eifelian age in six localities of the Barrandian area of the Central Bohemia of the Czech Republic. Formerly observed size and shape variations of Eurytholia sclerites prevent formal description of a new species on few specimens of Emsian and Eifelian age. Therefore the new specimens are identified as Eurytholia aff. bohemica. Their presence indicates longer time range of the Eurytholia animal, covering not only the Ordovician, the Silurian and the earliest Devonian as known formerly, but also late Lower Devonian and the Middle Devonian. Similar features in morphology and histology of Eurytholia indicate relationship to a conodont Pseudooneotodus and a support suggestion about the vertebrate origin of Eurytholia sclerites.
Thirty-two fossiliferous localities of the Olešná Member, a distinct unit of the Klabava Formation, are described. As we are able to find they represent all fossil sites of this unit ever been mentioned in publications. Fossil taxa from... more
Thirty-two fossiliferous localities of the Olešná Member, a distinct unit of the Klabava Formation, are described. As we are able to find they represent all fossil sites of this unit ever been mentioned in publications. Fossil taxa from relevant papers are summarized and the historical names used for the localities are listed. Updated lists of fauna are compiled for each locality; based on them an overall list for the member is completed.
The trilobite assemblage of Calceola-bearing beds in the upper part of Acanthopyge Limestone (Choteč Formation, Eifelian) in the Koněprusy area, the Czech Republic, is described. Together with occurrence of Calceola, it indicates absence... more
The trilobite assemblage of Calceola-bearing beds in the upper part of Acanthopyge Limestone (Choteč Formation, Eifelian) in the Koněprusy area, the Czech Republic, is described. Together with occurrence of Calceola, it indicates absence of significant palaeogeographic barriers restricting the distribution of the Rhenish-Type faunas in the Middle Devonian. The generic composition of the gathered trilobite assemblage somewhat differs from typical Acanthopyge-Phaetonellus assemblage characteristic for the Acanthopyge Limestone facies in possible absence and/or very rare occurrence of Phaetonellus, and only infrequent occurrence of Acanthopyge. Phacopid Chotecops cf. hoseri (Hawle et Corda, 1847) distinctly dominates; all other taxa are rather rare. Important is an occurrence of scutelluids of the Scutellum sensu lato group (preservation of remains does not enable more precise determination) and Longiproetus(?). Trilobite remnants are generally poorly preserved and very fragmented (onl...