Paleogeographic reconstruction of the continental water bodies of Ukraine in the Early-Middle Pleistocene based on ostracods (Arthropoda, Crustacea)

• Published in: Zoodiversity (Vestnik Zoologii)
• Date: 2026
• Volume: 60
• Issue: 4
• ISSN: 2707-7268
• Author Affiliations: N. I. Dykan — Institute of Geological Sciences of NAS of Ukraine, Ukraine — ORCID: 0000-0001-6631-7041
• Main Author: Dykan , N. I.
• Format: Article
• Language: English
• Published: Publishing House "Akademperiodyka" of the National Academy of Sciences of Ukraine 2026
• Online Access: https://ojs.akademperiodyka.org.ua/index.php/Zoodiversity/article/view/1042
• Journal Title: Zoodiversity

A paleogeographic reconstruction of Quaternary continental water bodies in Ukraine based on ostracods requires the data necessary for correlating the stages of development of water bodies in Eastern and Western Europe to be generalised, and synchronised with the general climatic trend of the Quaternary. A variety of methods and analyses were employed, including actualistic, quantitative modification, taphonomic, statistical, population, ecological, zoogeographical and biostratigraphic approaches. The detailed reconstruction of river and lake paleo-biotopes (type of biotope, degree of trophicity, water depth of biotope, m; water temperature , °C) in the paleo-valleys of the Zbruch, Southern Bug, Psol and Dnipro rivers during the Early to Middle Pleistocene (Calabrian – Holsteinian) has been conducted. A comparative analysis of the development of continental water bodies in Ukraine, Lithuania, Belarus and Central Russia during the Middle Pleistocene (Holsteinian) was conducted based on the results of studying freshwater ostracods of Eastern Europe. Correlating fluctuations (increases/decreases) in the water levels of paleo-water bodies located at considerable distances from each other reveals a general trend in water level changes caused by Interglacial Holsteinian climatic oscillations. It also reveals asynchrony (the partial displacement of positive and negative peaks relative to each other) and different water level fluctuation amplitudes caused by geographical zoning of the territory. According to the ostracods, the Holsteinian interglacial period had three warm stages (temperate stages I, II and III) and two cold stages (cold stages I and II). In southern water bodies (Ukraine), three stages of warming (temperate stages I, II and III) are recorded by an increase in water temperature. The first and third stages of warming (temperate stages I and III) are also recorded by an increase in water level. The second period of warming (temperate stage II) occurred during the first prolonged cold stage (cold stage I), which is indicated by rising water levels in northern bodies of water and only by an increase in water temperature in southern water bodies. Based on ostracods the timing of the formation and dynamics of a paleo-landslide in the paleo-valley of the Zbruch River during the Early Pleistocene (Calabrian) have been reconstructed.