Reproductive Biology of the Arborescent Seed-Fern Linopteris obliqua: Implications for Taxonomy (Medullosales, Late Pennsylvanian Sydney Coalfield, Canada)

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.

The Cuticles of (?) Thylacocephalan Arthropod from the Basal Choteč Event (Choteč Formation, Eifelian; Barrandian Area, Czech Republic)

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.

Specialized Adhesive Pad of a Climbing Pteridosperm from Permian Peat-Forming Forest (Wuda, Inner Mongolia)

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.

Biostratigraphically Important Findings of Two Index Trilobites from the Jince Formation (Cambrian, Drumian) of the Příbram-Jince Basin (Barrandian Area, Czech Republic)

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.

Problematic Sclerites Eurytholia from the Lower and Middle Devonian of the Czech Republic

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.

State of the Art of “Amphibian” Localities of the Letovice Subbasin (Boskovice Basin, Czech Republic)

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.

Lingulate Brachiopods of Tremadocian Age from the Abandoned Gabriela Mine (Krušná Hora, Central Bohemia, Czech Republic)

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.

Rodlets from Compressed Medullosalean Plant Fossils: Chemical and Morphological Studies (Late Pennsylvanian Sydney Coalfield, Canada)

Fragmented compression specimens of medullosalean fronds have been voluminously described over the past 200 years. However, the literature on rodlets is scarce. We addressed the questions (i) of common occurrence in these fronds, (ii) what made the fronds so strong to bear such a biomassive load, and (iii) what is the chemical make up of rodlets that expressed as striae and ridges (medullosalean hallmark) occur on these fronds? Recovered were soluble and insoluble, black, round and flat, opaque or translucent rodlets that are up to 5 mm long and ca. 10-111 μm wide, and are typed as (i) transparent, (ii) insoluble, or (iii) soluble in Schulze’s solution. In situ insoluble rodlets can be distinguished from associate coal and cuticle-free compression foliage and rachides by relatively high aromaticity and low aliphatics, although their chemical composition is unknown. Rodlets are presumably related to sclerenchymatous tissue in support of strength/stability of these sizeable medullosalean fronds.

Cuticles from Pennsylvanan Marattialean Fern “Pecopteris” Polypodioides (C. Presl in Sternberg) Němejc from Pilsen Basin (Czech Republic) and Sydney Coalfield (Canada)

Pennsylvanian fossil-fern cuticles are notoriously difficult to extract, little can be found in the palaeobotanical literature, yet they can supply significant taxonomic/systematic, phytostratigragphic, and palaeoenvironment information. This is demonstrated for cuticles from “Pecopteris” polypodioides of the coal basins in the Czech Republic and Canada. “Pecopteris” polypodioides is a marattialean tree fern which was part of the peat-forming flora, growing in a wet environment. Due to this fact, cuticles are generally very thin, and we assume that their major function was to reduce the ability of fungal spores to germinate and bacterial to grow, thereby reducing the possibility of these agents to cause disease. The secondary function was to be a major barrier to water loss and reducing the wettability of pinnules.

Vertebrate Microremains from the Pragian, Emsian and Eifelian of the Prague Basin (Czech Republic)

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.