ISSN 01458752, Moscow University Geology Bulletin, 2011, Vol. 66, No. 5, pp. 341–347. © Allerton Press, Inc., 2011. Original Russian Text © O.A. Orlova, A.L. Jurina, N.V. Gordenko, 2011, published in Vestnik Moskovskogo Universiteta. Geologiya, 2011, No. 5, pp. 42–47. First Finding of Archaeopteridaceae Wood in the Upper Devonian Deposits of the Middle Timan Region O. A. Orlovaa, A. L. Jurinaa, and N. V. Gordenkob a Faculty of Geology, Paleontology Department, Moscow State University, Moscow, 119899 Russia b Borissiak Paleontological Institute, Russian Academy of Sciences, ul. Profsoyuznaya 123, Moscow, 117997 Russia emails:
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[email protected] Received October 26, 2010 Abstract—Stem remains of Archaeopteridaceae with a wellpreserved anatomical structure were firstly found in the Upper Devonian deposits of the Middle Timan Region. The wood was studied under SEM and REM and was identified as Callixylon trifilievii Zalessky. Previous findings of Archaeopteridaceae in the northern part of European Russia and some taxonomic problems of the species were discussed. Keywords: Late Devonian, Archaeopteridaceae, anatomical structure, cohortoid pitting, and Middle Timan Region. DOI: 10.3103/S0145875211050073 INTRODUCTION pendent division Archaeopteridophyta (Snigirevskaya, 2000); there are those who refer them to division Pro Archaeopteridaceae is one of the most mysterious gymnospermophyta (Taylor et al., 2009). groups of spore plants; it grew circumglobally during Archaeopteris Dawson and Callixylon Zalessky are the Late Devonian until the Early Carboniferous. the two most thoroughly investigated morphological Every new finding of these plants extends the sug genera of Archaeopteridaceae. The former is charac gested territories of the first forest vegetation in the terized by isolated leaf imprints and related reproduc history of the Earth.