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SIBERIAN REPRESENTATIVES OF THE GENUS TRIANGULASPIS LERMONTOVA, 1940 TRILOBITES AND THEIR SIGNIFICANCE FOR THE CORRELATION OF CAMBRIAN DEPOSITS

I. V. Korovnikov

The analysis of morphological traits of the genus Triangulaspis showed that three valid species of this genus existed on the Siberian Platform in the Early Cambrian: Triangulaspis annio, Triangulaspis lermontovae, Triangulaspis meglitzkii. It is suggested that these trilobites may be links of the single phylogenetic branch, considering that they have a consistent position in the section and a gradual change in morphological traits. The intervals of stratigraphic distribution of the genus Triangulaspis representati ves have been clarified. The finds are typical for the Judomia – Uktaspis (Prouktaspis) zones of the Atdabanian stage (predominantly in the upper part) and Bergeroniellus micmacciformis – Erbiella zones of the Botomian stage of the Lower Cambrian (mainly in the lower part). The eastern part of the Siberian Platform is characterized by the genus representatives finds that are of great stratigraphic importance, because they mark a narrow transitional interval between the indicated stages. The species Triangulaspis annio has a great potential for trans-regional correlation, as it is determined not only on the Siberian Platform, but also in England, and morphologically similar representatives of the genus have been found in sections of Morocco, Spain, and North America.

Keywords: Cambrian, Siberian Platf orm, trilobites of the Triangulaspis genus.

DOI 10.20403/2078-0575-2025-2-3-16

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