Taimyria gen. nov., a new genus of evolutionary advanced gymnosperms from Triassic of the Taimyr Peninsula, Siberia, Russia
Abstract
New genus and species Taimyria triassica Naugolnykh et Mogutcheva gen. et sp. nov. of peltaspermalean affinity is described on the basis of material collected from the Keshinskian Formation (Induan stage, Lower Triassic), outcropped in the Tsvetkov Cape section (eastern part of the Taimyr Peninsula, Siberia, Russia). This new plant is characterized by both macromorphological and some microstructural features. Taimyria triassica has long racemose aggregations (cones or megastrobili) consisting of an axis with peltate seed-bearing discs (which also can be interpreted as seed-bearing semi-closed capsules), with margins curved adaxially. The seed-bearing discs are round to ovoid, with short stalk connected at central area of the adaxial part, and attached to the cone axis nearly perpendicularly, in a dense spiral pattern. Six to eight seeds are concentrically displayed around the stalk on the adaxial surface of the discs. The seeds preserved in seed-bearing discs were extracted from macerated reproductive organs and described as well. The seeds are platyspermic, ovoid, narrower at their apical micropylar end orientated toward the disc stipe. Problems of systematics and general evolutionary trends of the order Peltaspermales are briefly discussed.