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 antiquaAlekseeva (in Alekseeva and Nuzhdina, 1967) (subfamily Omoloninae),Geranocephalus inopinusCrickmay, 1954 andGeranocephaloides krivensisn. gen. n. sp. (subfamily Geranocephalinae),Newberria gigantean. sp., andRensselandioidea talyndzhaensisn. 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) theOmoloniaCommunity in early Givetian strata of the Baird Group, northwestern Brooks Range, Alaska; and 2) theOmolonia-Geranocephaloides-Newberria-RensselandioideaCommunity 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.