NEW DATA ON DIPLACANTHUS KLEESMENTAE VALIUKEVIČIUS, 1986FROM THE VITEBSK REGIONAL STAGE (UPPER EMSIAN)OF THE LOWER DEVONIAN OF BELARUS

Abstract

The paper presents new data on the acanthodian species Diplacanthus kleesmentae, whose isolated scales are often found in
terrigenous and carbonate-terrigenous rocks of the Vitebsk Regional Stage of the Upper Emsian of the Lower Devonian of Belarus
and are usually well preserved. A detailed study of the scales of this species made it possible to clarify its diagnosis, supplement the
morphological and histological description of the scales, and clarify the features of their morphological variability, compare them
with the scales of other known species of the genus Diplacanthus. In addition to the above-listed information, the paper also
provides data on the facies restriction of scales of the acanthodians belonging to this species, their stratigraphic allocation and
geographical distribution within the country. All currently known boreholes on the territory of Belarus, in which scales of this
species were found, are mentioned. The rocks in which these scales were found are listed. The paper also presents the data of the
associated organic remains (invertebrates, vertebrates and miospores) found together with the scales of this acanthodian
representative. The correlation of the deposits of the Obol and Lepel Beds of the Vitebsk Regional Stage of the Upper Emsian of
Belarus with the coeval sediments widespread in the adjacent territories of the Baltic States and Russia is given. The photographs of
the external appearance of the scales and their thin sections are shown. The Stratigraphic Chart of the Devonian deposits of
Belarus (2010) was used as the stratigraphic basis. The study of fossil ichthyofauna is of fundamental importance for the needs
of practice — solving specific problems in prospecting, exploration, geological survey and other geological works.

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