Lonchiphyllum aplospermum gen. et sp. nov.: An Anatomically Preserved Glossopterid Megasporophyll from the Upper Permian of Skaar Ridge, Transantarctic Mountains, Antarctica

Abstract

A new anatomically preserved megasporophyll, Lonchiphyllum aplospermum, is described from permineralized peat collected on Skaar Ridge in the central Transantarctic Mountains. This new genus contains vascular features similar to those of the leaf genus Glossopteris schopfii, which is the exclusive leaf genus in the specimens in which the sporophylls were found. The vasculature of the sporophyll consists of a central vascular region with bordered pitting and anastomosing lateral bundles with helical-scalariform thickenings. Ovules are attached oppositely to suboppositely to lateral veins on the adaxial surface of the sporophyll. There is an abundance of bisaccate pollen of the Protohaploxypinus type at the base of the ovules. The ovules of Lonchiphyllum are small (1.1 mm × 0.97 mm) and ovate and have an unornamented integument. Comparison with anatomically known ovules from Skaar Ridge, i.e., Plectilospermum elliotii, Choanostoma verruculosum, and Lakkosia kerasata and Homevaleia gouldii from the Bowen Basin of Australia, supports the classification of Lonchiphyllum as a glossopterid. The differences in the sarcotesta and sclerotesta of all the Skaar Ridge ovules may indicate specialization for pollination or dispersal.