The taxonomic status of the genus Rubidgea

Abstract

The genus Rubidgea Tate of the fossil family Glossopteridaceae was reduced to a synonym of Glossopteris by Seward (1907). Seward’s conclusion is now confirmed by a study of a wide range of imprints from a quarry near Hammanskraal, South Africa. The upper and lower surface imprints of a single leaf found on a split fragment of carbonaceous shale provides the main evidence presented. The finely striated upper surface imprint of the leaf could be identified with  Rubidgea, whereas the lower surface imprint represents the typical strong venation of a  Glossopteris. The type species of  Rubidgea is transferred to  Glossopteris as  G. mackayi (Tate) Kovacs comb. nov. The characteristics of upper and lower surface imprints of a number of  Glossopteris species are discussed.