The first stringocephalid brachiopods in the upper Givetian of Selennyakh Range (Northeast Asia) and their paleobiogeographical significance

Abstract

The following stringocephalid brachiopods are formally described from upper Givetian (late Middle Devonian) strata of the Selennyakh Range (Northeast Asia): Omolonia antiqua Alekseeva (in Alekseeva and Nuzhdina, 1967) (subfamily Omoloninae), Geranocephalus inopinus Crickmay, 1954 and Geranocephaloides krivensis n. gen. n. sp. (subfamily Geranocephalinae), Newberria gigantea n. sp., and Rensselandioidea talyndzhaensis n. sp. (subfamily Rensselandinae). Broad paleobiogeographical connections between the seas of Northeast Asia, northwest Alaska, western Canada (Manitoba), Nevada, and also between the seas of Northeast Asia and South China are clearly established in the Givetian. In addition, two new stringocephalid-bearing communities are established: 1) the Omolonia Community in early Givetian strata of the Baird Group, northwestern Brooks Range, Alaska; and 2) the Omolonia-Geranocephaloides-Newberria-Rensselandioidea Community in late Givetian strata of the Lower Prianikskay Subsuite in the Selennyakh Range, Northeast Asia, Russia. Both of these communities occur in shallow, quiet-water, lagoonal carbonate platform environments.