First Findings of Fossil Pollen of Ancestor Forms of Cathaya Conifers, a Modern Relic, and a Climate Indicator in the Paleogene and Neogene of West Siberia (Kulunda)

The palynological analysis of the Paleogene and Neogene sequences of the southern part of West Siberia (borehole 2, Novosibirsk oblast) showed that the conifer bisaccate pollen in the spore-pollen spectra exhibits a series of morphological features allowing its comparison with the modern pollen of Cathaya argyrophylla Chun et Kuang. These palynomorphs belong to relict vegetation, which currently occurs in the wet subtropical climate of South China, and are important climate indicators. The palynomorphs are ascribed to the ancestral forms of the species Cathaya as Abietineaepollenites sellowiiformis (Zaklinskaja) Doweld 2018. The pollen is described, and its distribution along the section is shown. The maximum amount of the A. sellowiiformis pollen (up to 23.7%) is confined to the upper part of the Oligocene and the Lower Miocene and its last appearance is recognized in the Middle-Upper Miocene. These data expand our knowledge on the geographic range of the Cathaya ancestral form and its role in plant communities of Central Asia in the Cenozoic.