Studies of the leaf cuticle fine structure of Zuberia papillata (Townrow) Artabe 1990 from Hoyada de Ischigualasto (Upper Triassic), San Juan Province, Argentina

Abstract

Zuberia is a leaf genus of the Mesozoic seed fern foliage that belongs to Corystospermales. Dispersed leaf cuticles of Zuberia papillata are described using conventional light and electron microscopy techniques (LM, SEM, and TEM). The cuticles were found in Hoyada de Ischigualasto, Ischigualasto Formation (Early Neotriassic), San Juan Province, Argentina. This research provides a new approach that may be useful for the comparison of the cuticle fine details among Zuberia species and other pteridosperms. The cuticle shows characters such as thick cuticle, papillae, stomatal apparatuses sunken and subsidiary cells with papillae overarching the suprastomatal aperture, which suggests adaptations to a megamonsoonal seasonal climatic regime as proposed to the Ischigualasto Formation. Furthermore, cuticle ultrastructural characters reveal new data about the paleoecology and taxonomic status of Zuberia.