Oguracaulis banksii gen. et sp. nov., a mid-Mesozoic tree-fern from Tasmania, Australia

Abstract

Oguracaulis banksii gen. et sp. nov. is described from permineralised specimens from Upper Jurassic-Lower Cretaceous strata near Ida Bay, Tasmania. The specimens consist of large fern stems and adhering petiole bases covered with thick root mantle. Their stems are characterised by a dictyostele with a sclerenchymatous sheath, numerous medullary bundles, an undivided leaf and petiolar vascular trace and multicellular epidermal hairs. This fossil fern provides evidence for the common origin for many of the modern cyatheaceous tree ferns including the cibotioids.