Abstract: 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 Prague Basin. The emended diagnosis of the ichnogenus is presented herein. PubDate: Mon, 07 Mar 2022 00:00:00 GMT
Abstract: The examined K-feldspars in arkoses of the continental Upper Carboniferous – Lower Permian of the West and Central Bohemian basins originated in the whole bed sequence (Duckmantian to Autunian; 314.2–297.1 Ma) from one source, which were so-called mountain granites of the older intrusive complex (OIC) of the Krušné hory Mts, as confirmed by the X-ray and geochemical analyses. The presence of feldspar clasts from other granitoids (Merklín and Louny massifs) was found only in the straight transgreding basal Carboniferous rocks. While other arkoses underwent synsedimentary and/or post-sedimentary kaolinization, in the deposits of Kaznějov and Horní Bříza (Nýřany Member of the Kladno Formation) pre-sedimentary kaolinization (sedimentation of sandstones and conglomerates with kaolinitic cement) occurred. PubDate: Mon, 07 Mar 2022 00:00:00 GMT
Abstract: Reported are results of an initial approximate imitation of a Carboniferous fern frond, i.e., marattialean Acitheca polymorpha (Schimper), Middle Pennsylvanian Sydney Coalfield, Canada. The simulation experiment is based on the analysis of 14 infrared spectra obtained by means of Fourier Transform Infrared spectroscopy from four detached fragments of sterile polymorphic penultimate-pinna compressions. The calculated relative, semi-quantitative, chemical data from the infrared spectra are the input for principal component analysis deriving a 3D (three-dimensional) chemometric model. To interpret it, the four specimens are placed in hypothetical-frond positions simulating a tripinnate frond, based on diminishing penultimate-rachial widths from 1-mm (distal) to 10-mm (proximal). Hypothetical conclusions include position-dependent chemistries, specifically that of opposing trends of aromaticity vs. aliphaticity in pinnules-rachises. This, in turn, would suggest potential for (i) fern-frond reconstruction, and (ii) for determination of a most likely frond position of fragmentary specimens by “chemical classification”; the predictive aspect. However, further experimental refinement is necessary particularly based on larger frond segments to confirm or disconfirm the overall hypothetical results. PubDate: Mon, 07 Mar 2022 00:00:00 GMT
Abstract: Certain pteridosperm tendril adhesive pads are depicted from the Cathaysian flora of the Early Permian Taiyuan Formation of Wuda Coal-field in Inner Mongolia China. Specimens contain elliptical or rounded pads situating at the swollen tip of pinnule lobe tendrils which are highly comparable to those of the extant Parthenocissus tricuspidata in the way that both of them are similar in form and function. Specifically, information we have gained suggested that pteridosperms from the Permian might have performed a similar type of physiological process by producing some chemical substances which assisted them in climbing. The Wuda pteridosperm likely to climbed on Cordaites or Sigillaria trees. Moreover, physical principles such as the pressure difference between inside and outside of the pads also seems to play an important role in assisting climbing. The new finding indicates that some pteridosperms in the Permian Cathaysian flora possessed climbing growth habit as well as those in the Late Carboniferous Euramerica Flora, where climbing/scrambling growth habit is well known in the coal swamp forests. This finding shows one of the several earliest climbing habits in Cathaysia Flora and thus remarkably promotes our understanding of the growth habit of pteridosperm and the change in plant community structure in that area. PubDate: Thu, 31 Dec 2020 00:00:00 GMT
Abstract: A shaley slab (65 x 45 x 7 cm) from the Sydney Coalfield, Canada, Cantabrian age, on splitting apart revealed 2 – 3 layers each entombing thousands of abscised pinnules of Linopteris obliqua and eight dispersed compound-synangial structures. The campanulary-ventral-sporal micromorphology of the best preserved structure of these compares sufficiently well with previously reported structures from the Sydney Coalfield named Potoniea krisiae. Earlier studies involving larger sampling suites furthermore contributed to the observation that Hexagonocarpus sp. (female organ) and P. krisiae (male organ) usually co-occur with abscised L. obliqua pinnules; however, these two organs do not co-occur on isochronous bedding planes. In the absence of confirmatory organic attachments, the presented data provide as yet the strongest support for the hypothesis of the organs’ connectivity, but whether female-male trees existed or not, and the mode of attachment of the organs remain unknown. Hypothesized for the latter is pinnate attachment. PubDate: Thu, 31 Dec 2020 00:00:00 GMT
Abstract: 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 bumps are about 1 μm sized and likely represents imprints of the epithelial cells adjoined to the basal membranous layer of endocuticle.Biological affinity of cuticle fragments is unclear. They surely represent pieces of the arthropod cara-pace, the most probably a thylacocephalan. Associated fossils indicate a deeper marine environment. Bloom of prasinophytes, abundance of dacryoconarids and organophosphatic brachiopods, and striking rarity and diminutive size of other fauna indicate eutrophic conditions in a neritic sea, likely with hypoxic bottom water. Nectonic mode of life in open sea can be suggested for an animal bearing this cuticle. PubDate: Thu, 31 Dec 2020 00:00:00 GMT
Abstract: This paper provides a summary of localization of Permian historical sites in the Boskovice Basin, which yielded amphibians of the family Discosauriscidae. Most of these sites have not been previously precisely localized. Our investigation is focused mainly on so-called “Špinar’s localities” named after Prof. Z. Špinar and described in his work. Several sites were also described by A. Stehlík, J. Zajíc & S. Štamberg and J. Augusta. The reason for the localization of these locations is that more than 3,000 samples from these sites are stored at the Chlupáč’s Museum of Earth History of the Charles University in Prague. Most localities are situated around the village of Bačov, where carbonization is the dominant type of preservation of Palaeozoic amphibian skeletons. PubDate: Mon, 27 Jul 2020 00:00:00 GMT
Abstract: 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. PubDate: Mon, 27 Jul 2020 00:00:00 GMT
Abstract: Lingulate brachiopods are described from a lithic sandstone referred to the upper part of the Třenice Formation. Loose blocks were sampled from a dump of abandoned Gabriela Mine in Krušná Hora Hill near Beroun, Central Bohemia. Apart of the Acrotreta aff. grandis Klouček, 1919, genera Teneobolus, Rosobolus, Broeggeria, Rowellella and Siphonobolus are distinguished. Comments to their ontogeny, affinity, stratigraphical and spatial occurrences and taphonomy are discussed. PubDate: Sat, 29 Jun 2019 00:00:00 GMT
Abstract: Litavkaspis rejkovicensis Fatka, Kordule et Šnajdr from the Příbram-Jince Basin has been known to occur in a roughly 30 m thick eponymous Taxon-range Zone situated in the lower parts of the Jince Formation (Cambrian, Drumian), within the Eccaparadoxides pusillus Interval Zone. A unique finding of a cranidium of Litavkaspis sp. at the locality Jince-Vystrkov, described in this report, comes from the middle parts of the Paradoxides gracilis Taxon-range Zone, lying roughly 250 m higher than the hitherto known biostratigraphically youngest occurrence of the index taxon. Specimens of Dawsonia bohemica (Šnajdr) from the Jince Formation have been collected exclusively in about 1 m thick deposits of the eponymous Taxon-range Zone situated stratigraphically at the base of the Onymagnostus hybridus Interval Zone. The findings of Dawsonia cf. bohemica presented herein come from the localities Rejkovice – Potůček in the Litavkaspis rejkovicensis Taxon-range Zone, and Rejkovice – Ve žlutých in the Acadolenus snajdri Interval Zone. Their stratigraphic positions are therefore 30–50 m lower than the typical occurrence of Dawsonia bohemica (Šnajdr) in the eponymous Taxon-range Zone. PubDate: Sat, 29 Jun 2019 00:00:00 GMT
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