Corystosperms and Other Gymnosperms from the Triassic–Jurassic of Southern Paraná Basin, Brazil: Vegetative and Fertile Structures

Seed ferns represented by Dicroidium, cycads, Ginkgophyta, conifers, and rarer sphenophytes and pteridophytes characterize the macroflora in the southern Paraná Basin and grew up in the interior areas of subtropical Gondwana since Triassic to Jurassic, when the Umkomasiales became absent in the deposits. By its strategic paleogeographic position between South Africa and Argentina and a location in an area that represents the frontier between the warm–temperate climatic belts (not so distinct from today), the taphofloras from South Brazil have an outstanding value. Together with other macrofloras from southern America and Africa and of Australasia, they help to understand the influence of the environmental and climatic changes over all vegetation and about the two catastrophic events: the Permian-Triassic extinction and Carnian pluvial event, during the beginning of Late Triassic. This chapter aims to furnish an update about the South Brazilian Triassic macrofloras and associate deposits, looking for their relations with other southern Gondwana and global areas. Considering that the source of the Lower-Middle Mesozoic floras from South Brazil is a red bed succession (Santa Maria Supersequence), like others worldwide dispersed, this chapter also tries to establish the proposed data about their stratigraphic, paleoecological, and taphonomic relations. Additionally, Dicroidium genus and its allied forms, still controversial and sometimes doubtful in it taxonomic insertion, an overall picture about the more recent knowledge concerning to this is furnished.