Climate Evolution

The region under study is the administrative part of the municipalities of Khulo and Adigeni. It is located on the Arsiani ridge, the watershed of the rivers Dzindza (to the east) and Acharistskali (to the west), at the height of 2025 meters. The region was distinguished by strong volcanic activity during the Mio-Pliocene, the products of eruption of which are referred in geological literature as the Goderdzi suite. As a result of field work, in the sub suite of the Goderdzi suite, several new locations of the fossil floristic complex were discovered uniquely preserved and represented by species diversity. The present paper reports on the results of the identification of the well-preserved remnants of fossil flora of different sizes and morphologies and their importance for the reconstruction of palaeoclimatic regime. It was found that out of 12 samples of the fossil flora only the representatives of Lauraceae were recorded and the rest were not found until today. It could be said t...

The geological survey in NW Iran (Ahar area, Ghalandar village) carried out by the Czech Geological Survey in the years 2007-2009 provided new data on the geology, coal petrography and palaeobotany of this part of the eastern Paratethys. The recovered plant impressions, dated by radiometric ages of associated volcanic rocks to the Oligocene, have been identified as Osmunda parschlugiana (Unger) Andr., Picea (sect. Omorika) sp., cf. Magnolia sp., Eotrigonobalanus furcinervis (Rossm.) Walther & Kvaček, cf. Acer aegopodifolium (Göpp.) Baik. and Dicotylophyllum subpeltatum Kvaček sp. nov. The site characterizes a new floristic assemblage ("complex") Ghalandar in the eastern Paratethys, which differs from the Oligocene broad-leaved evergreen floristic assemblage of Dilizhan previously defined from the Caucasus area by the mixed-mesophytic character of forest vegetation. • Key words: flora, Oligocene, eastern Paratethys, Iran. KVAČEK, Z. & BUBÍK, M. 2016. A new Oligocene leaf assemblage from the Ghalandar area (NW Iran) and its contribution to understanding of floristic evolution in the eastern Paratethys. Bulletin of Geosciences 91(4), 705-715 (6 figures). Czech Geological Survey, Prague.

The classification of the genus Salix (Salicaceae) is troubled by the intra-specific flexibility and diversity of the morphological features. The aim was to prepare a comparative description of petiole anatomy of 23 species of Salix, in addition to two species of Populus and Bivinia jalbertii, as well as to determine the taxonomic importance of petiole features. In order to do so, 10 quantitative and 10 qualitative petiole anatomical features were studied. Moreover, a Bayesian analysis was executed on the relevant ITS sequences obtained from GenBank, included 28 specimens from 17 species. The anatomical features were then mapped on the resulted cladogram and the ancestral states of some prominent petiole anatomical features were reconstructed. Based on the results, no stomata were observed in the petiole's epidermis of any of the species studied; therefore, it could be assumed that the petiole in the studied species is dependent to the leaf blade for respiration and gas exchange...

Dioscorea section Lasiophyton leaflets from the late Oligocene (27.23 Ma) and Tacca leaves from the early Miocene (21.73 Ma) of north-western Ethiopia greatly expand the known fossil record of Dioscoreaceae and represent the earliest and only known records of the Afro-Asian trifoliate, palmately veined yams (Dioscorea) and bat flowers (Tacca). Both fossils occur in volcaniclastic and clastic sediments associated with a high water table, and the palaeofloral assemblages are indicative of tropical moist forest formations. These fossils provide insight into the evolutionary history of the family in Africa during the mid-Cenozoic and provide well-dated taxa that can assist in phylogenetic analyses and evolutionary divergence studies for Dioscoreales and Dioscoreaceae.

The diatomites exposed in the surroundings of Badaogou town, in the counties of Linjiang and Changbai, Jilin Province of China, bear a rich Neogene leaf assemblage. Previously, the most similar living relatives (MSLRs) of Sassafras paratsumu Chen (Lauraceae), Acer rotundatum Huzioka (Sapindaceae, subfam. Aceroideae, sect. Platanoidea), and A. trifoliatum Geng (Sapindaceae, subfam. Aceroideae, sect. Trifoliata) have been determined based solely on gross morphology. Cuticle preservation in the plant material from Badaogou allows the comparison of epidermal features. Thus, Sassafras tzumu (Hemsley) Hemsley is confirmed as the unambiguous MSLR of S. paratsumu. The cuticular features of Acer rotundatum best match A. mono Maximowicz and A. cappadocicum Gleditsch. Only the stoma and aperture length are slightly shorter in A. mono than in A. cappadocicum, therefore more closely resembling A. rotundatum. Based on gross morphology, earlier workers already regarded A. triflorum Komarov as the MSLR of Acer trifoliatum. The cuticle, however, bears some differences. In A. trifoliatum the stomata are slightly bigger, the adaxial surface is only faintly, if at all, striate, and the anticlinal walls are straight; in A. triflorum, however, the anticlinal walls are undulate and the surface shows distinct striation. Compared to other East Asian members of sect. Trifoliata -A. griseum (Franchet) Pax, A. mandshuricum Maximowicz, and A. maximowiczianum Miquelthe combination of features match best with A. triflorum. This includes leaflet shape and size, trichome bases of simple, filiform trichomes girdled by roundish cells, and the presence of uniserial, short-celled, glandular trichomes in intercostal areas abaxially. The modern counterparts of the fossil taxa are elements of the modern flora of China.