NEW DATA ON THE LATE PALEOZOIC LEPYDOPHYTES OF THE ORULGAN RANGE (NORTHERN VERKHOYANSK REGION).

To date, the Late Paleozoic lepidophytes of the Orulgan range (Northern Verkhoyansk Region) were represented by the genera Angarophloios, Angarodendron, Lophiodendron, Tomiodendron. In 2014, the author, together with I.V. Budnikov, R.V. Kutygin, L.G. Peregoedov and V.I. Makoshin studied the sections of the Lower Carboniferous layer-by-layer in the upper reaches of the Sobolokh-Mayan River (the Bylykat and Nimnecheen rivers) and made new collections of fossil flora. During monographic studying the collection of fossil flora, lepidophytes of the genera Angarophloios, Lophiodendron, and Tomiodendron were discovered in the Bylykat Formation. The author also studied the collection of flora made by I.V. Budnikov in 1988 in the section of the Bylykat and Setachan Formations on the Nimnecheen river, where in the Setachan Formation, in the rare remains of flora, an imprint of the axis of a large lepidophyte was found with closely spaced leaf cushions of a heart shape, with ligule pit in the absence of heels, sub-leaf blisters and wings. These signs indicate that this specimen belongs to the genus Ursodendron, previously not known in Verkhoyansk Region. Representatives of the genus Ursodendron were known from the Lower Carboniferous sediments of the Altai-Sayan mountain region, the southern regions of the Siberian Platform (Rybinsk depression) and southern Mongolia, and the MiddleUpper Carboniferous of the Tunguska basin. The identification of the genus Ursodendron in Verkhoyansk Region significantly expanded the geography of its distribution. [ABSTRACT FROM AUTHOR]