MORFOLOGÍA DEL POLEN DE APTEROCLADUS LANCEOLATUS ARCHANG. (CONIFERAE) DE LA FORMACIÓN BAQUERÓ, PROVINCIA DE SANTA CRUZ

Juan C Gamerro

Abstract


A study has been made of the morphology of the pollen found in male gymnosperm canes in organic connection, or associated with, leafy branches and cuticles. The material was found in the Baqueró Formation, Lower Cretaceous, Bajo Grande Locality, Santa Cruz Province (Argentina). The morphology of the leaves and features of the cuticle indicates with a high degree of probability that Apterocladus lanceolatus Archang. may be classífíed in the Podocarpaceae. The pollen presents three very incipient wings surrounding the equatorial region of the pollen body, and is similar to the pallen morphospecies Zonalapollenites dampieri Balme ando Z. Trilobatus Balme. The known distribution of these, and other related specíes, would poínt to a worldwide area for Apterocladus or allied plants during the Jurassic and part of the Cretaceous Periodo The particular morphology of these pollen grains would seem to corroborate Wodehouse's hypothesis on the origin of the bladders in Podocarpaceae, These would have originated by the falling off of the external layer of the exine, from the border of the germinal furrow in the monocolpate pollen type, which we find in the Bennettítales, Cycadales, Ginkgoales, etc.

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