Itaquaquecetuba Formation, Sao Paulo basin, Brazil: new angiosperm components of Paleogene Taphoflora

Among the various geological formations found in the State of Sao Paulo, the Itaquaquecetuba Formation, located in the Sao Paulo sedimentary basin, is one of the richest in Cenozoic plant fossils, allowing a detailed study of the flora which existed in that region, from the Paleogene to the Early Neogene. The plants identified in this formation, in general, belong to the families Melastomataceae and Fabaceae of the angiosperms group. In this study, one foliar impression of Leandra (Melastomataceae), being this the first fossil record of the genus, and one of Bauhinia (Fabaceae) were identified. These foliar fragments allowed us to observe in detail the leaf architecture and then to carry out the generic assignment. The form assigned to the genus Leandra resembles more the current species L. acutiflora and that assigned to the genus Bauhinia suggests affinity with B. divaricata. However, the ancient registration and the lack of an accuracy of the diagnostic characteristics lead us to use Leandra sp. and Bauhinia aff. B. divaricata designations. Some aspects of the paleogeography of both genera are discussed.