New data on Silurian vertebrates of southern Siberia

This paper presents revised data on Silurian conodonts, graptolites and vertebrates of southern Siberia. We define patterns of facies associations of agnathans and fishes from Silurian basins of the Tuva region in southern Siberia based on original and published data. The agnathans display a mosaic distribution: Tuvaspis margaritae Obruchev plus Tannuaspis levenkoi Obruchev, Helenolepis navicularis Karatajute-Talimaa, and Helenolepis obruchevi Karatajute-Talimaa plus Loganellia scotica (Traquair) occur in littoral, sublittoral and distal uplifted sublittoral environments, respectively. Elegestolepis grossi Karatajute-Talimaa fish taxa occur in both littoral and sublittoral environments, whereas those of Tuvalepis schultzei Zigaite and Karatajute-Talimaa are more typical of distal uplifted environment. Our obtained data contribute to the understanding of the Silurian biostratigraphy and litho- and biofacies of the whole region.