Abstract 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 indicates advancing and finally successful defence of the host crinoid against the epibiont. The holdfast gives evidence that the small host crinoids offered a somewhat higher tier for even smaller epibiont crinoids. However, other observed holdfasts indicate fixation of larva and growth over loose bioclasts lying on a sea bed. Location of foraminifer test on bioclasts confims that foraminifers cemented and grew on loose echinodermal and brachiopod remains and preferred crevices and similar protected sites with concave profiles. This is clear evidence that diverse bioclasts (brachiopod shells, pelmatozoan ossicles) provided the hard substrate suitable for epibiont life on a sea bed.
{"title":"Diminutive Epibionts on Crinoid Stems from the Lower/Middle Devonian Boundary in the Barrandian, Czech Republic","authors":"M. Mergl, Nikola Šmídtová","doi":"10.2478/fbgp-2022-0003","DOIUrl":"https://doi.org/10.2478/fbgp-2022-0003","url":null,"abstract":"Abstract 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 indicates advancing and finally successful defence of the host crinoid against the epibiont. The holdfast gives evidence that the small host crinoids offered a somewhat higher tier for even smaller epibiont crinoids. However, other observed holdfasts indicate fixation of larva and growth over loose bioclasts lying on a sea bed. Location of foraminifer test on bioclasts confims that foraminifers cemented and grew on loose echinodermal and brachiopod remains and preferred crevices and similar protected sites with concave profiles. This is clear evidence that diverse bioclasts (brachiopod shells, pelmatozoan ossicles) provided the hard substrate suitable for epibiont life on a sea bed.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"14 1","pages":"27 - 42"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77762228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The construction of the new metro line D in Praha-Pankrác provides a unique opportunity to study different aspects such as lithology, stratigraphy and fossil assemblages from the Upper Ordovician and Silurian of the Prague Basin. Results from the sections in tunnels mined so far allowed detailed information about the succession of fossil assemblages, facies variability and actual thicknesses of the upper part of the Bohdalec Formation, the Králův Dvůr and Kosov formations in this part of Prague Basin. The stratigraphic position of Michle Facies in the Bohdalec Formation was also indicated.
{"title":"Construction of the Metro Line D in Praha-Pankrác: An Introductory Report About a Unique Opportunity for Study of the Upper Ordovician Fossil Assemblages and Sediments in the Prague Basin (Czech Republic)","authors":"J. Bruthansová, J. Bruthans, P. Kraft","doi":"10.2478/fbgp-2022-0006","DOIUrl":"https://doi.org/10.2478/fbgp-2022-0006","url":null,"abstract":"Abstract The construction of the new metro line D in Praha-Pankrác provides a unique opportunity to study different aspects such as lithology, stratigraphy and fossil assemblages from the Upper Ordovician and Silurian of the Prague Basin. Results from the sections in tunnels mined so far allowed detailed information about the succession of fossil assemblages, facies variability and actual thicknesses of the upper part of the Bohdalec Formation, the Králův Dvůr and Kosov formations in this part of Prague Basin. The stratigraphic position of Michle Facies in the Bohdalec Formation was also indicated.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"130 1","pages":"69 - 80"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73123229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The earliest known Cyrtina in the Prague Basin has been discovered in the Kotýs Limestone of the Lochkov Formation (Lochkovian) among a rich brachiopod-coral fauna at Branžovy ridge near Bubovice (Beroun District, Czechia). Rare and imperfectly preserved silicified shells are assigned to Cyrtina praecedens Kozłovski, 1929, a species originally described from Podolia, Ukraine. The species is known also in north-eastern Russia (Tajmyr and Sette-Daban Mts) and likely also in New South Wales, Australia. Its distribution provides evidence of the rapid spread of Cyrtina across the shallow shelves of Laurussia, Siberia and Gondwana in the Early Devonian. The Devonian and Carboniferous distribution of Cyrtina is restricted to the agitated, shallow-water carbonate environment in tropical and temperate climatic belts.
{"title":"The Earliest Cyrtina (Brachiopoda, Cyrtinidina) in the Devonian of the Barrandian (Czech Republic)","authors":"M. Mergl","doi":"10.2478/fbgp-2022-0001","DOIUrl":"https://doi.org/10.2478/fbgp-2022-0001","url":null,"abstract":"Abstract The earliest known Cyrtina in the Prague Basin has been discovered in the Kotýs Limestone of the Lochkov Formation (Lochkovian) among a rich brachiopod-coral fauna at Branžovy ridge near Bubovice (Beroun District, Czechia). Rare and imperfectly preserved silicified shells are assigned to Cyrtina praecedens Kozłovski, 1929, a species originally described from Podolia, Ukraine. The species is known also in north-eastern Russia (Tajmyr and Sette-Daban Mts) and likely also in New South Wales, Australia. Its distribution provides evidence of the rapid spread of Cyrtina across the shallow shelves of Laurussia, Siberia and Gondwana in the Early Devonian. The Devonian and Carboniferous distribution of Cyrtina is restricted to the agitated, shallow-water carbonate environment in tropical and temperate climatic belts.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"1 1","pages":"1 - 10"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74402891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Reported are descriptions of twelve samples representing a variety of sideritic structures, including nodules mostly from roof shale of the Middle Pennsylvanian Sydney Coalfield, Canada. The co-occurrence of fossiliferous nodules and compression fossils in the shaley roof rocks at Point Aconi enhance greatly palaeontological information. Newly discovered in a coal seam, and part of the sample, is a 40 mm thick continuous sheet-like layer of siderite with abundant permineralized-like-compressed small to micron-sized structures in a rather evenly-sized sideritic matrix, probably indicating a genetic origin different from that of the nodules. Methods include some thin-section, and two X-Ray analysis. However, large systematic sampling is a prerequisite to explore that situation, which additionally could provide faunal information for Euromerican correlation.
{"title":"Seminal Insights Concerning the Variety of Sidertic Structures and Variable Genesis and of Sideritic Occurrences: An Unexplored Source of Palaeontological Information (Sydney Coalfield, Middle Pennsylvanian, Canada)","authors":"E. Zodrow, J. Pšenička","doi":"10.2478/fbgp-2022-0004","DOIUrl":"https://doi.org/10.2478/fbgp-2022-0004","url":null,"abstract":"Abstract Reported are descriptions of twelve samples representing a variety of sideritic structures, including nodules mostly from roof shale of the Middle Pennsylvanian Sydney Coalfield, Canada. The co-occurrence of fossiliferous nodules and compression fossils in the shaley roof rocks at Point Aconi enhance greatly palaeontological information. Newly discovered in a coal seam, and part of the sample, is a 40 mm thick continuous sheet-like layer of siderite with abundant permineralized-like-compressed small to micron-sized structures in a rather evenly-sized sideritic matrix, probably indicating a genetic origin different from that of the nodules. Methods include some thin-section, and two X-Ray analysis. However, large systematic sampling is a prerequisite to explore that situation, which additionally could provide faunal information for Euromerican correlation.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"3 1","pages":"43 - 56"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72975306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The extant plant genus Isoetes (Isoetaceae; lycophyte, quillwort) is important from an evolutionary point of view. Species of this heterosporous genus are small herbs (up to 50 centimeters) and exhibit some morphological, anatomical and embryological features of their Paleozoic arborescent lycopsid ancestors. The species Isoetes pantii produces three kinds of microspores (monolete, alete and trilete) and two types of trilete megaspores in one and the same heterosporangium. We attempt to associate these unusual functional megaspores with various Paleozoic spores described mainly from Devonian barinophytaleans such as Omniastrobus dawsonii, Barinophyton richardsonii, B. citrulliforme and Protobarinophyton pennsylvanicum. These have two kinds of spores in a sporangium and provide the first palynological evidence of heterospory at 405 Ma. The germination of microspores and megaspores and production of gametophytes within the heterosporangia of I. pantii corresponds with that of some of its Paleozoic ancestors. Retention of megaspores within heterosporangia and their germination in situ offers evidence that I. pantii exhibits the probable route of evolution of the seed habit. These observations support the hypothesis that a typical heterosporangium was the cradle for the evolution of heterospory.
摘要:现存的水韭属植物;从进化的角度来看，石松(冬虫夏草)是重要的。这个异孢子属的物种是小型草本植物(可达50厘米)，并表现出其古生代树栖石松祖先的一些形态、解剖和胚胎学特征。在一个异孢囊中产生三种小孢子(单孢子、双孢子和三孢子)和两种三孢子大孢子。我们试图将这些不寻常的功能大孢子与各种主要来自泥盆纪钡生植物的古生代孢子联系起来，如Omniastrobus dawsonii, Barinophyton richardsonii, B. citrulliforme和Protobarinophyton pennsylvania。它们在一个孢子囊中有两种孢子，提供了405 Ma异孢子的第一个孢粉学证据。异孢子囊内小孢子、大孢子的萌发和配子体的产生与其古生代的一些祖先相一致。异孢子囊内大孢子的保留及其原位萌发提供了证据，表明大孢子具有种子习性的可能进化途径。这些观察结果支持了一个典型异孢子囊是异孢子进化的摇篮的假设。
{"title":"Heterosporangia in Isoetes Pantii (Isoetaceae, Pteridophyta): Revealing the Beginnings of Heterospory and Recalling Paleozoic Ancestors?","authors":"J. Bek, H. Goswami","doi":"10.2478/fbgp-2022-0002","DOIUrl":"https://doi.org/10.2478/fbgp-2022-0002","url":null,"abstract":"Abstract The extant plant genus Isoetes (Isoetaceae; lycophyte, quillwort) is important from an evolutionary point of view. Species of this heterosporous genus are small herbs (up to 50 centimeters) and exhibit some morphological, anatomical and embryological features of their Paleozoic arborescent lycopsid ancestors. The species Isoetes pantii produces three kinds of microspores (monolete, alete and trilete) and two types of trilete megaspores in one and the same heterosporangium. We attempt to associate these unusual functional megaspores with various Paleozoic spores described mainly from Devonian barinophytaleans such as Omniastrobus dawsonii, Barinophyton richardsonii, B. citrulliforme and Protobarinophyton pennsylvanicum. These have two kinds of spores in a sporangium and provide the first palynological evidence of heterospory at 405 Ma. The germination of microspores and megaspores and production of gametophytes within the heterosporangia of I. pantii corresponds with that of some of its Paleozoic ancestors. Retention of megaspores within heterosporangia and their germination in situ offers evidence that I. pantii exhibits the probable route of evolution of the seed habit. These observations support the hypothesis that a typical heterosporangium was the cradle for the evolution of heterospory.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"37 1","pages":"11 - 26"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86686847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
František Hartl, V. Vokáč, M. Pavlovic, T. Mrázek, Martin Šafka
Abstract The deep-water Aulacopleura koninckii Assemblage in the lower Homerian (T. testis Sub-Biozone) “Aulacopleura shales“ strata at the classical ‘Barrande’s pits’ locality on the Černidla hillside at Loděnice in the Prague Basin is supplemented by the addition of two new trilobite taxa, viz. Exallaspis? perunicana sp. n. and Kosovoproetus? aff. praecursor (Přibyl & Vaněk 1987). The palaeogeographic distribution of Exallapis Ramsköld & Chatterton, 1991 is extended by the occurrence of Exallaspis? perunicana sp. n. and the younger Exallaspis sp. in the upper Homerian (the P. parvus – G. nassa Biozone) of the Prague Basin, reflecting the faunal migration between the southern shelf of the Baltica palaeocontinent and the Perunica microcontinent accross the Rheic Ocean. The small dimensions of the K.? aff. praecursor exoskeletons compared to those of K.? praecursor in the bordering shallow-water Liolalax–Sphaerexochus– Cheirurus Assemblage represent another example of adaptive nanism in trilobites of the Aulacopleura-Raphiophorus Biofacies.
{"title":"The Rare Trilobites Exallaspis (Odontopleuridae) and Kosovoproetus? (Tropidocoryphidae) in the Homerian (Silurian) Of The Prague Basin, Bohemian Massif","authors":"František Hartl, V. Vokáč, M. Pavlovic, T. Mrázek, Martin Šafka","doi":"10.2478/fbgp-2022-0005","DOIUrl":"https://doi.org/10.2478/fbgp-2022-0005","url":null,"abstract":"Abstract The deep-water Aulacopleura koninckii Assemblage in the lower Homerian (T. testis Sub-Biozone) “Aulacopleura shales“ strata at the classical ‘Barrande’s pits’ locality on the Černidla hillside at Loděnice in the Prague Basin is supplemented by the addition of two new trilobite taxa, viz. Exallaspis? perunicana sp. n. and Kosovoproetus? aff. praecursor (Přibyl & Vaněk 1987). The palaeogeographic distribution of Exallapis Ramsköld & Chatterton, 1991 is extended by the occurrence of Exallaspis? perunicana sp. n. and the younger Exallaspis sp. in the upper Homerian (the P. parvus – G. nassa Biozone) of the Prague Basin, reflecting the faunal migration between the southern shelf of the Baltica palaeocontinent and the Perunica microcontinent accross the Rheic Ocean. The small dimensions of the K.? aff. praecursor exoskeletons compared to those of K.? praecursor in the bordering shallow-water Liolalax–Sphaerexochus– Cheirurus Assemblage represent another example of adaptive nanism in trilobites of the Aulacopleura-Raphiophorus Biofacies.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"32 1","pages":"57 - 68"},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86126945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"Source of K-Feldspars and Kaolinitization in Arkoses of West and Central Bohemian Continental Permo–Carboniferous","authors":"Jiří Jiránek, J. Klomínský, Jana Jiránková","doi":"10.2478/fbgp-2021-0002","DOIUrl":"https://doi.org/10.2478/fbgp-2021-0002","url":null,"abstract":"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.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"286 7","pages":"23 - 37"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72571193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"First Record of Podichnus in Byronid Shell from the Lower Devonian (Pragian) of the Prague Basin, Czechia","authors":"M. Mergl","doi":"10.2478/fbgp-2021-0003","DOIUrl":"https://doi.org/10.2478/fbgp-2021-0003","url":null,"abstract":"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.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"100 1","pages":"39 - 44"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79459087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
摘要本文报道了一种石炭系蕨类植物叶片的初步近似模拟结果，即，maratialean Acitheca polymorpha (Schimper)， mid pennsylvania Sydney Coalfield, Canada。利用傅里叶变换红外光谱对4个分离的不育多态次耳廓压缩片段进行了14个红外光谱分析，并进行了仿真实验。从红外光谱中计算出的相对、半定量的化学数据是主成分分析的输入，推导出三维化学计量模型。为了解释这一点，根据倒数第二臂宽度从1毫米(远端)减少到10毫米(近端)，将四个标本放置在模拟三棱叶的假设前肢位置。假设的结论包括位置依赖的化学反应，特别是芳香性和脂肪性的相反趋势。反过来，这将表明:(1)蕨类植物叶片重建的潜力，以及(2)通过“化学分类”确定碎片标本最可能的叶片位置的潜力;预测方面。然而，进一步的实验改进是必要的，特别是基于更大的前段，以证实或否定整体假设结果。
{"title":"3D Chemometric Model Simulating the Acitheca Polymorpha Frond: Implications for Reconstructing Carboniferous Ferns (Marattiales, Canada)","authors":"J. D'Angelo, E. Zodrow, J. Pšenička","doi":"10.2478/fbgp-2021-0001","DOIUrl":"https://doi.org/10.2478/fbgp-2021-0001","url":null,"abstract":"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.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"3 1","pages":"1 - 21"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86067219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"The Cuticles of (?) Thylacocephalan Arthropod from the Basal Choteč Event (Choteč Formation, Eifelian; Barrandian Area, Czech Republic)","authors":"M. Mergl","doi":"10.2478/fbgp-2020-0001","DOIUrl":"https://doi.org/10.2478/fbgp-2020-0001","url":null,"abstract":"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.","PeriodicalId":12284,"journal":{"name":"Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica","volume":"32 1","pages":"1 - 12"},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85483268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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