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Chemnitz, Germany

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.


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.


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.


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.


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.

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