The Late Cretaceous (Coniacian) leaf and cone flora from the Sudetes

Abstract

Late Cretaceous (Coniacian, mostly late Coniacian; ammoniteand inoceramid-based stratigraphy) leaf floras from theNysa Kłodzka Graben in the Sudetes (south-western Poland) are described. Plant remains are preserved in coarse clastic rocks as imprints devoid of cuticles and occur in marginal marine sediments deposited by a palaeocurrent flowing along the shores of the East Sudetic Island, the origin place of the plants. The main fossil plant localities are Idzików (Kieslingswalde) and NowyWaliszów (Neuwaltersdorf ). The leaf flora consists of thirty-three species, described on the basis of about 320 identifiable specimens. Five fern species (belonging to Nathorstia, Monheimia, cf. Anemia, and Sphenopteris) are mostly represented by single specimens. Conifers are represented by Geinitzia reichenbachii (Geinitz) Hollick & Jeffrey and Frenelopsis aff. alata (K. Feistmantel) Knobloch (foliage) and Geinitzia cf. schlotheimii L. Kunzmann, Knoll&Gaipl andConago sp. (cones). The bulk of the flora consists of twenty-four dicot species, representing the generaDryophyllum, Juglandiphyllites,Dalbergites,Debeya (all the above Eudicotyledoneae),Cinnamomoides, Laurophyllum, Magnoliphyllum, Ficonium, Ettingshausenia, Amelanchites, Dryandroides, Apocynophyllum, Salicites, and Dicotylophyllum (Dicotyledoneae incertae sedis). Dryophyllum geinitzianum (Goepp.) Halamski & J. Kvaček comb. nov. is sufficiently well preserved to allow a detailed reconstruction: it is a compound trifoliolate leaf composed of folioles with irregularly serratemargins; it belongs to theorderFagales s.l.Twonewspecies aredescribed.Dicotylophyllummontis-nivium sp.nov. is characterised by ovate leaves that are entire-margined in most specimens, whereas in some they possess single large teeth.Dicotylophyllum thaddaeiguniae sp. nov. is elliptic in shape, entire-margined, but has a peculiar rectangular base reminding of that of Credneria senonensis (Knobloch)Němejc&Kvaček. GeneraDalbergites,Cinnamomoides,Magnoliphyllum, and Ficonium are emended.Monocots are represented by Pandanites cf. spinatissimus Petrescu & Duşa ex Popa et al. and Smilacites panartius (Bayer) Halamski & J. Kvaček comb. nov. The most common species in the studied material are Laurophyllum acuminatum (Goepp.) J. Kvaček&Halamski comb. nov. and Dryophyllum geinitzianum (the two representing about half of the material), both presumably dominating a riparian forest. Upland or mesophilousvegetationmightbe representedbyAmelanchites cerasiformis (Vel.)Halamski&J.Kvačekcomb.nov.,Dicotylophyllum montis-nivium sp. nov., and several small-leaved representatives of Dalbergites and Dicotylophyllum. Frenelopsis grew in salt marshes, whereas Pandanites andGeintizia belong to back swamp vegetation. The studied flora belongs to the subtropical vegetation belt and is most similar to slightly older or younger (Turonian to Santonian) assemblages from the BohemianCretaceous Basin. Notable similarities with the flora of the Cenomanian to lower Coniacian Frontier Formation inWyoming should also be noted.