Tomiostrobus is an extinct quillwort genus from the Early Triassic of Australia and Russia, which was especially widespread in the aftermath of Permian Triassic mass extinctions.[2]

Juvenile plant of Tomiostrobus australis from the Early Triassic Newport Formation near Narrabeen, NSW
Corm with root scars at base of fertile Tomiostrobus australis from the Early Triassic Gosford Formation near Terrigal, NSW

Tomiostrobus australis is preserved as whole plants closely spaced within bedding planes, and lived as an early successional weed in lake and pond sedimentary environments, like living Isoetes. Unlike living Isoetes, Tomiostrobus formed closed cones with sporophylls that were distinctly shouldered and woody. This may have been an adaptation to heavy grazing by herbivorous therapsids.[1]