Estudios cuticulares de Ginkgoites Seward del Cretácico Inferior de Patagonia

Resumen

Cuticular studies of Ginkgoites Seward from the Lower Cretaceous of Patagonia. The
anatomy and ultrastructure of the leaf cuticles of Ginkgoites ticoensis Archang. and G. skottsbergii Lund. is
studied. Both taxa were collected in Santa Cruz province, G. ticoensis from the Anfiteatro de Tico Formation
(Aptian) and G. skottsbergii from the Kachaike Formation (Albian). The cuticular studies were made by means
of electronic microscopy (SEM, TEM). These observations showed that G. ticoensis has hypostomatic leaves,
papillae on both cuticles, and monocyclic stomata with 5-7 papillate subsidiary cells; while G. skottsbergii presents
amphistomatic leaves, and monocyclic to dicyclic stomata with 6-8 subsidiary cells partially papillate. At the
ultrastructural level the cuticular membrane has three layers, which are clearly distinct in both species.
Comparisons with the leaf cuticle of other ginkgoalean taxa are also made.