Friedsellowia gracilifolia gen. nov. et sp. nov., a new gnetophyte from the Lower Cretaceous Crato Formation (Brazil) - Löwe, Sarah A.; Mohr, Barbara A. R.; Coiffard, Clément; Bernardes-de-Oliveira, Mary Elizabeth Cerruti (Palaeontographica, Abt. B: Palaeobotany-Palaeophytology, 2013)