Ruffordia goeppertii (Schizaeales, Anemiaceae): a common fern from the Lower Cretaceous Crato Formation of northeast Brazil - Mohr, Barbara A. R; Bernardes-de-Oliveira, Mary Elizabeth Cerruti; Loveridge, Robert; Pons, Denise; Sucerquia Rendón, Paula Andrea; Castro-Fernandes, Maria Cristina de (Cretaceous Research, 2015)