Plane-Trees Used To Grow In Siberia 85 Million Years Ago

The Cretaceous that lasted approximately from 135 through 65 million years ago was the period of drastic changes in biosphere. It was at that time that mass extinction of dinosaurs and other reptiles took place; birds and mammals came to take their place. In the early Cretaceous, the first flowering plants appeared, they quickly occupied the dominant position overland and settled in diverse ecotopes. These large-scale processes, thanks to which the Earth gradually acquired the contemporary appearance, draw rapt attention of researchers.

In Western Siberia, only few locations of the Cretaceous plant remains exist, therefore, each new find of them brings the most valuable information on flora evolution in this vast territory. One of such finds was made quite recently, in July 2005, by palaeobotanist Lina Golovneva, specialist of the Komarov Botanical Institute, Russian Academy of Sciences (St. Petersburg), and her colleagues in the expedition organized with support of the Russian Foundation for Basic Research. The researchers worked near Antibes village in the Kemerovo Region, where on sandy slopes of desolated open pits they found clay interlayers containing multiple imprints of ancient plants’ leaves. According to the preliminary estimate, their age makes approximately 85 million years; they used to grow back in the Coniacian stage of the Cretaceous. Other locations of plants of this age are not yet known in Western Siberia.

The majority of plant remains found near Antibes are imprints of tree leaves known under the scientific name of trochodendroides (which relate to contemporary redbud – a beautiful tree from Japan and China that is also sometimes cultivated in Russian parks) and paraprotophyllum (a close relative to a plane-tree normally growing in the Caucasus, the Crimea and along boulevards of Paris). The bilobate leaves of liriophyllum are found more rarely in this area; their shape reminds that of the North American tulip-tree’s (liriodendron’s ) leaves. There also were discovered imprints of a peculiar fern, resembling Venus’ hair, its reproductive organs however having a totally unique structure.

Strictly speaking, phytolites near Antibes village were for the first time found back at the end of the 20s of the last century by Professor V.A. Khaklov (Tomsk University); at the end of the 30s, they were investigated by student V.K. Cherepnin. Unfortunately, these scientists managed to collect only one and a half dozens of specimen, which is evidently insufficient for a more or less complete characteristic of the ancient flora. The open pit where they found remains of ancient plants does not exist any longer.

Although Lina Golovneva had set off for Antibes to follow in the tracks of V.A. Khaklov and V.K. Cherepnin, the location she discovered turned out really new. And much more “productive” than those found by her predecessors: about one and a half hundred of plant specimen were collected here belonging to at least 16 species. Possibly some of these species are new to science, their detailed investigation is still ahead.

So, 85 million years ago, forests of trees related to modern plane-trees used to grow in the south of Western Siberia instead of today’s taiga and forest-steppe. Apparently, the climate was warm and mild at that time; such trees would not endure the present Siberian winter. How long these deciduous forests existed and what vegetable communities came to take their place – is yet unknown; only new finds of extinct plants’ remains will be able to provide answers to these questions.