DILCHER, DAVID L.*, ANA FLORA MANDARIM-DE-LACERDA, ALCINA M.F. BARRETO, AND MARY E.C. BERNARDES-DE-OLIVEIRA. Florida Museum of Natural History, University of Florida, Gainesville, FL 32611-7800; Departamento de Biologia Animal e Vegetal, Universidade do Estado do Rio de Janeiro, Rio de Janeiro,RJ, Brazil, 20550-900; Departamento de Geologia, Universidade Federal de Pernambuco, Recife, PE, Brazil, Universidade de São Paulo, São Paulo, SP, Brazil, 05422-970. - Selected fossils from the Santana Formation, Chapada do Araripe, Brazil.
Collections from Universidade de São Paulo (USP), Universidade Federal
de Pernambuco (UFPE), Universidade Guarulhos (UnG)and Universidade
Rural do Carirí (URCA) have been examined to provide a survey of the
nature of the plants preserved in the lithographic limestone of the
Crato Member of the Santana Formation. The Crato Member is basal in
the Santana Formation and considered to be middle Aptian in age. The
depositional environment is considered to be lacustrine preserving
numerous well-know invertebrates, vertebrates and ichnofossils
associated with palynomorphs and megafossils. The diversity of
megafossil plant remains includes several different types of plants,
many of which are also found as palynomorphs in the sediment. Some
small herbaceous appearing plants have roots and stems with leaves
attached similar to some species of Schizoneura. Isoetes-like
clusters of sporophylls and leaves are associated with a small stem
and a unique vegetative fern axis with doubly compound leaves are
present. One small trilobed conifer scale occurs in these sediments.
More common fossils are the Gnetales such as Ephedra-like
stems, some bearing leaves and some bearing bracts enclosing seeds, as
well as various types of isolated leaves. The other common gnetalian
fossils are Welwitschia-like winged seeds, seedlings bearing
two seed-leaves and isolated young leaves. Four angiosperm leaf types
are represented by one leaf each and each one having a distinct form
and venation. An angiosperm follicle, several winged fruits and a
cluster of three large petals are also present.
Key words: Brazil, Cretaceous-Aptian, megafossil plants, Santana Formation