Svetlana Popova, Torsten Utescher, Anna Averyanova, Valentina Tarasevich, Polina Tropina, Yaowu Xing
Komarov Botanical Institute of RAS, Palaeobotanical Department, 2 Professor Popov Str., Saint Petersburg, 197376, Russia.
Steinmann Institute, Bonn University, Nussallee 8, Bonn, D-53115, Germany.
Plant Divers. 2019 Apr 16;41(3):183-197. doi: 10.1016/j.pld.2019.04.002. eCollection 2019 Jun.
The investigation of the fossil floras from the Turgai plateau (central Kazakhstan) contributes to a better understanding of the origin of the temperate Turgai type flora which spread to Kazakhstan and adjacent areas during the Oligocene-Miocene transition. In this paper, we present the results of a carpological and palynological study of the Kumyrtas flora collected from a flora-bearing horizon of the regional coal-bearing Zhilanchik suite, dated to the Aquitanian period. Pollen analysis identified 33 taxa, with are dominated by angiosperms (about 73%) and reflect zonal vegetation. The high percentages of (27%) and (7.5%) that were found in this flora allows comparisons with other Aquitanian floras of Kazakhstan. Based on descriptions of fossil fruits and seeds, we determined that 19 taxa were dominant; these taxa had meosphytic herbaceous components, suggesting mostly edaphic local conditions. The incongruence between the carpological and the pollen records suggests a significant taphonomical effect. Quantitative reconstruction of the palaeoclimate based on pollen records supports---and slightly extends---previous findings based on fossil leaf data, but contradicts findings deduced from the carpological record. Plant Functional Type (PFT) classification was used to characterize the vegetation patterns. Pollen records show that about 45% of diversity relates to the arboreal broadleaved deciduous components and ca. 35% to conifers. Fossil fruit and seed data indicate riverine vegetation with a high diversity of aquatic components and shrub stratum.
对图尔盖高原（哈萨克斯坦中部）化石植物群的研究有助于更好地理解温带图尔盖型植物群的起源，该植物群在渐新世 - 中新世过渡期间扩散到哈萨克斯坦及邻近地区。在本文中，我们展示了对从区域含煤的日兰奇克组的一个含植物层位采集的库米尔塔斯植物群进行果实学和孢粉学研究的结果，该层位的年代为阿基坦期。花粉分析确定了33个分类群，其中被子植物占主导（约73%），反映了地带性植被。在该植物群中发现的高比例的（27%）和（7.5%）使得能够与哈萨克斯坦的其他阿基坦期植物群进行比较。基于对化石果实和种子的描述，我们确定有19个分类群占主导；这些分类群具有中生草本成分，表明主要是土壤局部条件。果实学记录和花粉记录之间的不一致表明存在显著的埋藏学效应。基于花粉记录对古气候的定量重建支持并略微扩展了先前基于化石叶片数据的发现，但与从果实学记录推断出的结果相矛盾。使用植物功能类型（PFT）分类来表征植被模式。花粉记录显示，约45%的多样性与乔木阔叶落叶成分有关，约35%与针叶树有关。化石果实和种子数据表明是具有丰富水生成分和灌木层的河流植被。
