Chemnitz, Germany
Chemnitz, Germany
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Rossler R.,DAStietz | Philippe M.,CNRS Geological Laboratory of Lyon: earth, planets and environment | van Konijnenburg-van Cittert J.H.A.,Laboratory of Palaeobotany and Palynology | van Konijnenburg-van Cittert J.H.A.,Naturalis Biodiversity Center | And 37 more authors.
Taxon | Year: 2014

Araucarioxylon Kraus is a widely known fossil-genus generally applied to woods similar to that of the extant Araucariaceae. However, since 1905, several researchers have pointed out that this name is an illegitimate junior nomenclatural synonym. At least four generic names are in current use for fossil wood of this type: Agathoxylon Hartig, Araucarioxylon, Dadoxylon Endl. and Dammaroxylon J.Schultze-Motel. This problem of inconsistent nomenclatural application is compounded by the fact that woods of this type represent a wide range of plants including basal pteridosperms, cordaitaleans, glossopterids, primitive conifers, and araucarian conifers, with a fossil record that extends from the Devonian to Holocene. Conservation of Araucarioxylon has been repeatedly suggested but never officially proposed. Since general use is a strong argument for conservation, a poll was conducted amongst fossil wood anatomists in order to canvass current and preferred usage. It was found that the community is divided, with about one-fifth recommending retention of the well-known Araucarioxylon, whereas the majority of others advocated use of the legitimate Agathoxylon. The arguments of the various colleagues who answered the poll are synthesized and discussed. There is clearly little support for conservation of Araucarioxylon. A secondary aspect of the poll tackled the issue as to whether Araucaria-like fossil woods should be either gathered into a unique fossil-genus, or whether two fossil-genera should be recognized, based on the respective presence or absence of axial parenchyma. A majority of colleagues favoured having one fossil-genus only. Agathoxylon can be used legitimately and appears to be the most appropriate name for such woods. However, its original diagnosis must be expanded if those woods lacking axial parenchyma are to be included. © International Association for Plant Taxonomy (IAPT) 2014.

Feng Z.,Yunnan University | Feng Z.,CAS Nanjing Institute of Geology and Palaeontology | Rossler R.,DAStietz | Annacker V.,DAStietz | Yang J.-Y.,Yunnan University
Gondwana Research | Year: 2014

A new bipinnate fertile pinna, Sterzelitheca chemnitzensis, bearing alternate synangia, is described from the Chemnitz Petrified Forest, Germany. The specimen occurs in the basal volcanic ash of the Zeisigwald Tuff Horizon, Leukersdorf Formation, Lower Permian. Because it is partially embedded in the tuffaceous matrix, X-ray micro-computer tomography was employed to investigate the complete morphology without mechanical preparation of the hand specimen. The pinna is 66. mm long and branched once at least, the ultimate pinnae alternately positioned on the penultimate axis at angles of 45-55°. Stalked synangia are bell-like, borne alternately on both the terminal portion of the penultimate axis and the ultimate axes at angles of 25-60°. The smooth walled stalk is 3-7. mm long, 1-1.5. mm wide. Individual synangia are up to 6.5. mm in diameter and 10. mm long, and bear 12-14 elongated sporangia. Tubular sporangia are thin walled, circular in transverse section, arranged at the rim of the circular synangial pad around a central hollow. The unique preservational mould of the studied specimen is neither a permineralisation nor a compression-impression. It is three-dimensionally preserved, but lacks any organic remains. We provide the first detailed three-dimensional features of a probable medullosan male reproductive organ from the Chemnitz Fossil Lagerstätte. The relatively simple structure of the specimen offers a better understanding of the Palaeozoic seed ferns. © 2013 International Association for Gondwana Research.

Feng Z.,Yunnan University | Feng Z.,CAS Nanjing Institute of Geology and Palaeontology | Schneider J.W.,TU Bergakademie Freiberg | Schneider J.W.,Kazan Federal University | And 5 more authors.
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2015

Oribatid mites (Acari: Oribatida) are very diverse and important detritivorous and fungivorous micro-arthropods in modern forest ecosystems. Although the fossil record of oribatid mites can be traced to the Early Devonian, the paleoecology of oribatid mites during the deep geological past remains poorly understood. Remarkably good preservation of tunnel networks in a permineralized conifer wood specimen is described from the Early Permian of Germany. This fossil provides evidence for four aspects of oribatid mite feeding habits. First, there is preferred consumption of the more indurated tissues from growth-ring cycles. Second, tracheids were targeted for consumption. Third, feeding on tissues resulted in fecal pellet accumulations at the bottoms of tunnels. And fourth, the absence of feeding on ambient decomposing fungi such as necroses and rots, but rather the processing of pristine plant tissues, indicate the presence of a self-contained, microorganismic gut biota. These rather specialized feeding habits allowed oribatid mites a prominent role in the decomposition of digestively refractory plant tissues in Early Permian ecosystems. © 2014 Elsevier B.V.

Mencl V.,Charles University | Holecek J.,Charles University | Rossler R.,DAStietz | Sakala J.,Charles University
Review of Palaeobotany and Palynology | Year: 2013

Silicified stems are very abundant in the upper Palaeozoic basins of the Czech Republic. The results of an anatomical study of the silicified calamitalean stems from the Krkonoše Piedmont and Kladno-Rakovník basins are presented here for the first time. In the Krkonoše Piedmont Basin, there are various silicified plant remains, but the presence of calamitalean wood is restricted to only one stratigraphic unit, to the so-called "Ploužnice Horizon". Only a few data on the systematics of permineralised or petrified stems from the Kladno-Rakovník Basin are available, anatomical descriptions are largely lacking and fossilised calamitalean stems were unknown. The fossils can be attributed to two species: the common Arthropitys cf. bistriata and the rare Calamitea striata; the occurrence of the latter is limited to the Krkonoše Piedmont Basin. © 2013 Elsevier B.V.

Rossler R.,DAStietz | Zierold T.,DAStietz | Feng Z.,DAStietz | Feng Z.,Yunnan University | And 4 more authors.
Palaios | Year: 2012

A recently excavated locality in the Chemnitz Petrified Forest, lower Permian in age and occurring within the Leukersdorf Formation of the Chemnitz Basin, Germany, provides evidence for an outstanding fossil assemblage buried in situ by pyroclastics. The environment is interpreted as forested lowland that sheltered a dense hygrophilous vegetation of ferns, sphenophytes, and gymnosperms, as well as a diverse fauna of reptiles, amphibians, arthropods, and gastropods. A detailed measured section of the outcrop documents the early volcanic history of the Chemnitz fossil forest, including a paleosol that shows the root systems of Psaronius tree ferns, Arthropitys calamitaleans, and Medullosa and Cordaixylon gymnosperms in the same horizon. Fifty-three trunks are still standing upright and rooted at their place of growth, providing evidence that the top of the paleosol was the land surface on which the forest grew, thereby offering insights into the original plant community structure and density. Taphonomic analysis of both the petrified and adpression-fossil assemblages enable us to reconstruct the direction, estimate the violence and extent of the volcanic events, and their effects on the entire ecosystem. A complete dataset of three-dimensional coordinates resulting from three and one-half years of continuing excavation and study permits the recognition of organ connections and results in the first reconstructions of the excavation site, the floral elements, and the plant community as a whole. © 2012 SEPM (Society for Sedimentary Geology).

Tavares T.M.V.,Claro | Rohn R.,Claro | Roler R.,DAStietz | Noll R.,In den Birkengarten 30
Review of Palaeobotany and Palynology | Year: 2014

This study concerns silicified fertile pecopterid pinnae from the Permian of the Parnaíba Basin, State of Tocantins, northern Brazil, attributed to a new fern taxon of Marattiales, Buritiranopteris costata gen. nov. et sp. nov. This fern bears groups of three or four sporangia radially arranged in closely spaced synangia, as in some species of Scolecopteris and Acitheca, but they are completely enclosed in thick and long down-curved foliar lobes. This morphology may represent a xeromorphic adaptation against long seasonal drought and direct solar irradiation. These pinnae obviously belonged to one of the abundant marattialean tree ferns, most probably Tietea, which were apparently successful as riparian vegetation of ephemeral rivers. © 2013 Elsevier B.V.

Neregato R.,Claro | Rossler R.,DAStietz | Rohn R.,Claro | Noll R.,In den Birkengarten 30
Review of Palaeobotany and Palynology | Year: 2015

New sphenophyte stems from the Permian of the Parnaíba Basin (central-north Brazil) are described in detail and assigned to Arthropitys, a genus that was recognised from the Euramerican and Cathaysian floristic provinces. The fossil material is reported from the Permian Motuca Formation in northern Tocantins and was discovered in fluvial deposits, which originated under seasonal conditions in a widely distributed alluvial plain environment. The silica-petrified specimens are three-dimensionally preserved and provide considerable information on histological and developmental details not previously observed in the genus. The stems show very regular branch traces, attached branches or basal branching stumps. Based on their anatomical and morphological characteristics two new species are described: Arthropitys isoramis sp. nov. and Arthropitys iannuzzii sp. nov. One specimen of A. isoramis sp. nov. shows several woody roots attached to the basal region of the stem. This record differs radically from traditional and largely generalised reconstructions of calamitaleans, which are largely understood as rhizomatous trees based on inferences with extant Equisetum. The new sizable finds underline the high potential of northern Tocantins as a widely extended fossil lagerstätte that significantly enlarges our understanding of extinct low-latitude Southern Hemisphere floral communities. © 2015 Elsevier B.V.

Rossler R.,DAStietz | Noll R.,In den Birkengarten 30
International Journal of Coal Geology | Year: 2010

Sizable permineralized calamitean trunks from the Permian petrified forest of Chemnitz, Germany, enabled us to recognize two different branching patterns and wood anatomies for material currently classified as Arthropitys bistriata. This resulted in re-evaluation of the generitype of the widely distributed organ genus Arthropitys Goeppert 1864. As a result, a mosaic of anatomical and morphological characteristics has been recognized that permit A. bistriata to be characterized in much more detail than previously possible. The first type of calamite previously included in A. bistriata is characterized by whorls of branches at every 5th to 9th node and simple scalariform thickenings in tracheid walls of the secondary xylem. Additionally it shows irregularly positioned woody adventitious shoots that also carried whorls of leafy branches. The second type shows reticulated thickenings and multiseriate pitting in secondary xylem tracheid walls and regular branching at every node. Branches alternate in successive nodes and, therefore, lie on the top of each other at every second node. Comparison with the type material suggests the two calamite forms need to be split taxonomically as follows. The first type of calamite is regarded as A. bistriata and emended herein, the second type is separated and introduced as Arthropitys sterzelii sp. nov. The secondary tissues of both species are characterized by a high portion of parenchyma (around 45%). Sometimes irregular growth rings were recognized that may reflect some kind of seasonality and/or environmental influence. We suspect the leafy branches, which were free of any secondary growth in both species, were probably grown and abscised seasonally. Comparisons are made with both different calamitean species and other preservational forms. © 2009 Elsevier B.V.

Rossler R.,DAStietz | Feng Z.,DAStietz | Feng Z.,Yunnan University | Noll R.,In den Birkengarten 30
Review of Palaeobotany and Palynology | Year: 2012

The largest petrified calamite is reported from the Early Permian fossil forest of Chemnitz, Germany. For the first time a sizable specimen of Arthropitys bistriata permits insights into both the internal anatomical structure and the spatial architecture of the complex branching system. The arboreal woody plant is characterized by a height of more than 10. m and at least three orders of axes which formed a large crown. Ontogenetic analyses of the main stem and the various branches of the plant demonstrate that most of the morphological and anatomical features that have been previously recognized as important inter-specific distinctions exhibit a considerable variability. Spheroid to elongate ovoid coprolites have been recognized in the pith cavity of one woody branch ranging from 1.4-2.8 × 2-5.8. mm in diameter. Semi- or undigested fragments of tracheids in the coprolites are identical with those of the parent plant and indicate their histologically pristine nature. According to the coprolite size and fossil records of detritivorous animals, we tentatively suggest that these coprolites were produced by specialized ancient myriapods. Growth rings are densely developed in the peripheral portion of the trunk in particular. As well as climatic cyclicity, they suggest that volcanism-induced environment turbulences become more serious and frequent, and finally buried the whole ecosystem in situ. © 2012 Elsevier B.V.

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