Acta Palaeobot. 43(2): 137–259, 2003 The Pliocene flora of Kholmech, south-eastern Belarus and its correlation with other Pliocene floras of Europe* Felix Yu. VELICHKEVICH1 and Ewa ZASTAWNIAK2 1Institute of Geological Sciences, National Academy of Sciences of Belarus, Zhodinskaya str. 7, 220141 Minsk, Belarus 2W. Szafer Institute of Botany, Polish Academy of Sciences, Lubicz 46, 31-512 Kraków, Poland; e-mail: [email protected] Received 17 November 2003; accepted for publication 18 December 2003 ABSTRACT. The aim of the study is to provide a monograph of the Pliocene carpological flora at the Kholmech site in south-eastern Belarus. Fossil material was collected from an excavation located on the right bank of the Dnieper river. Very abundant macrofossils, several tens of thousands of specimens, comprising mainly seeds, fruits and megaspores, were collected from peaty gyttja deposits. The specimens represent 170 taxa contained in 82 genera and 46 families of cryptogamic and angiospermous plants. Most (137 taxa) were identified to species level. Gymnospermous plants were represented by only one fragment of a Picea needle. Six species new for the Pliocene in Europe, from the genera Ceratophyllum, Cyperus, Lycopus, Schoenoplectus, and one new combination in the genus Teucrium are described here. All the taxa are described and illustrated, some of them using the SEM. On the basis of the taxonomic composition of the Kholmech fossil flora, its age has been established as the beginning of the Late Pliocene. Floras of this type are known at several other localities in south-western and western Belarus. The flora of the Kinelian series in the Middle Volga basin, the Simbugino flora in Bashkiria, the Dan’shino flora in central Russia, all in the east, and the floras of Kłodzko, the Vildštein Formation and Rippersroda in the west are of the same age as that from Kholmech. Comparison of the floristic compositions of the Kholmech and Mizerna floras in southern Poland reveals that the true counterpart of the Kholmech flora is complex II/III of the Mizerna flora and not Mizerna complex II as had previously been thought. KEY WORDS: fruits, seeds, megaspores, fossil flora, palaeoenvironment, correlation, Pliocene, Belarus, Poland, Europe CONTENTS Introduction . 138 Araceae . 170 History of palaeobotanical investigations . 139 Iridaceae . 171 Lemnaceae . 171 Geological setting . 140 Myricaceae . 171 Material and methods . 141 Betulaceae . 171 Description of taxa . 142 Corylaceae . 173 Selaginellaceae . 142 Fagaceae . 173 Marsileaceae . 144 Urticaceae . 173 Salviniaceae . 145 Polygonaceae . 175 Azollaceae . 147 Chenopodiaceae . 177 Pinaceae . 149 Silenaceae . 178 Typhaceae . 149 Nymphaeaceae . 179 Sparganiaceae . 150 Cabombaceae . 181 Potamogetonaceae . 152 Ceratophyllaceae . 183 Najadaceae . 154 Ranunculaceae . 184 Alismataceae . 156 Droseraceae . 188 Hydrocharitaceae . 158 Rosaceae . 188 Cyperaceae . 160 Staphyleaceae . 190 * This work was supported by the State Committee of Scientific Research (Grant No. 6 P04D 061 20). 138 Euphorbiaceae . 191 Taxonomic composition and geographical Aceraceae . 191 elements . 208 Tiliaceae . 192 Reconstruction of the vegetation and palaeoen- Hypericaceae . 192 vironment . 216 Onagraceae . 193 Flacourtiaceae . 194 Geological age and correlation of the Kholmech Violaceae . 194 flora . 217 Lythraceae . 195 Belarus and Lithuania . 220 Haloragaceae . 196 Russia – Upper Don Basin . 222 Apiaceae . 197 Russia – Middle Volga Basin and Pre-Ural Cornaceae . 198 Area . 223 Primulaceae . 199 Central and western Europe . 224 Menyanthaceae . 200 The Mizerna flora in the light of comparable Lamiaceae . 200 investigations of the fossil floras of the Late Solanaceae . 205 Pliocene of Eastern Europe . 228 Caprifoliaceae . 205 Acknowledgements . 229 Valerianaceae . 206 Lobeliaceae . 207 References . 229 Asteraceae . 207 Plates . 237 INTRODUCTION The necessity of a precise description of par- roughly equal to that of the Pleistocene (about ticular phases of flora development in the Late 2.8 million years, e.g. Lindner 1992, Makh- Cenozoic has long been a pressing concern in nach et al. 2001). It seems very small when palaeobotanical studies. During recent de- compared with the Miocene, which existed for cades it has become one of the most important 17 million years. desiderata of Tertiary palaeobotany. One of the One more difficulty in palaeobotanical main factors creating this situation was the studies of the Pliocene is the poor repre- change of the Pliocene boundaries in the sentation of deposits of this age in the Euro- stratigraphic division of the Neogene which re- pean ancient glacial zone. These deposits occur duced the duration of its existence. The as rare local layers of relatively small thick- Miocene/Pliocene boundary, set at about 5.3 ness (from a few to several tens metres). It is million years BP, is generally accepted. The likely that large parts of the Pliocene deposits upper boundary of the Pliocene has not yet were destroyed by the first continental gla- been fixed precisely following controversial ciers. Only their small remnants could have opinions on the beginning and duration of the been preserved in depressions of erosive or tec- Pleistocene (e.g. Starkel 1991, Lindner 1992, tonic origin. Only a few profiles of Pliocene de- Makhnach et al. 2001). At first, the Pleis- posits containing plant macrofossils are scat- tocene was considered exclusively as the peri- tered in the vast region from the Pre-Ural area od of continental glaciation development. Then to the Atlantic Ocean. The macroscopic floras the boundary between the Pliocene and Pleis- found in these profiles vary greatly and often tocene was set to coincide with the palaeomag- bear little similarity to one another. Some- netic inversion of Brunhes-Matuyama, i.e. at times it is possible to include within the about 760 000 years BP. Later on, when the Pliocene transitional floras linking the early traces of the first clear climate cooling Pliocene with the Late Miocene. Again Early had been defined, the lower boundary of the Pleistocene floras may be considered as be- Pleistocene was moved to coincide with the Ol- longing to the Late Pliocene, particularly when duvai palaeomagnetic episode (about 1.8 mil- the flora dating has been performed with re- lion years BP). Recently new evidence has ap- gard to the new, enlarged formulation of the peared, causing a further movement in the Pleistocene. Therefore arrangement of the lower boundary of the Pleistocene to 2.4–2.5 Pliocene floras of different age, even within million years BP. If this boundary is accepted one region, is very difficult. as the beginning of the Pleistocene, the period Another difficulty in the cognition and of the Pliocene becomes considerably shorter, correlation of Pliocene floras arises from the 139 different opinions among European palaeobo- as one of the key units in the correlation of the tanists concerning the interpretation of fossil floras of the Late Pliocene in eastern and cen- material. These differences of view involve tral Europe. such problems as the range of variability of ex- tinct species, their longevity, relationship with present-day plant taxa etc. The authors of the HISTORY OF PALAEOBOTANICAL present study prefer to distinguish many INVESTIGATIONS small, stenochronous taxa which can provide a basis for fossil flora correlation (Velichkevich The first mention of Pliocene plant macro- 1994, 1999). Such an approach to the research fossil discoveries on the right bank of the of floras, especially those of the Pliocene, has Dnieper river (between the cities of Rechitsa revealed some curiosities in the taxonomic and Loev, in south-eastern Belarus; Fig. 1), composition of floras of different ages and based on a preliminary experts’ report by P.I. shown the existence of distinct groups. It has Dorofeev and F.Yu. Velichkevich, was included also made possible correlation of the most in a publication by Goretsky (1970). It gave typical floras of different age from neighbour- data on the fossil floras of Dvorets (51 taxa) ing or mutually separated regions. and Kholmech (90 taxa), estimated in age to The Kholmech flora is typically Pliocene, be early (Kholmech) and late (Dvorets) Late clearly differing from the richly exotic Miocene Pliocene. Based on a letter by P.I. Dorofeev floras and the poor and very characteristic dated 15th January 1970, Goretsky (1970, p. Pleistocene floras. This flora was formed in an 128) wrote: “....the Kholmech flora is un- isolated local water body surrounded by im- doubtedly of the Pliocene, of a Kinelian type mense swamps and, remaining undisturbed, corresponding not to the lowest but to the has provided evidence of the taxonomic compo- middle horizons of the Kinelian series in Bash- sition of the plant communities present at that kiria. The Krivobor’e flora is somewhat older, time. The Kholmech flora has also illustrated but the Ivnitsa and Dan’shino floras are very the level of evolution of many plant taxa of ex- similar to the Kholmech one”. ceptional importance for Pliocene stratigraphy Goretsky (op.cit.) cited a long list of extinct in the East-European Plain. The exceptional Pliocene species which allowed him to corre- importance of the Kholmech flora for palaeo- late the Kholmech and Pliocene floras in cen- floristic studies was recognized by Mai (1995b) tral Russia. Dorofeev (1971) described 6 new who accepted the “Kholmech floristic complex” species for the Pliocene of Belarus (Typha as- Kholmech Dvorets Dnieper river Fig. 1. View of the right bank of the Dnieper between Dvorets and Kholmech villages 140 pera Dorof., T. pseudoovata Dorof., Potamoge- Palynological studies of the main part of the ton borysthenicus Dorof., P. cholmechensis Dorof., Kholmech profile were performed by Rylova Nymphaea borysthenica Dorof., and N. pusilla (1982). In a pollen diagram the proportion of Dorof.). At that time Dorofeev and Velichke- coniferous plant pollen was small (1–8%, on vich (1971a) produced a list of the Kholmech average below 3%). Pollen of several Pinus fossil flora containing 105 taxa, mainly herbs. species (P. cf. sylvestris L., P. cf. strobus L., P. Another fossil flora, of similar taxonomic tertiaria (Moreva) Anan., P.