ESPORAS Y GRANOS DE POLEN DEL JURASICO DE NEUQUEN (REPUBLICA ARGENTINA). 1. DESCRIPCIONES SISTEMATICAS

Abstract

Fifty-six species of plant microfossils frorn seven subsurface samples of the Middle ]urassic of Neuquén Pravince (Argentina) are recorded, They consist of micraspores (28 species, belonging to 17 genera) and pollen grains (28 species belonging to 13 genera). 12 species are new: Hymenopbyllumsporites grandis, Baculatisporites bagualensis, B. tenuis, Uvaesporites minimus, lscbyosporites labiatus, Polypodiaceoisporites neuquenensis, Cirratrira- dites minar, 1naperturopollenites uelatus, Araucariacites pergranulatus, Cycadopites granulatus, Cycadopites punctatus, Cycadaceaelagella nana. The main bulk of the micrafloras studied consists of conifer pollen grains of Classopollis= Araucariacites -and Vitreisporites type. In one microfloristic association, Todisporites major (the spores of Todites Williamsoni) and monosulcate grains are strangly represented. The presence of Microcachryidites antarcticus indicates that the micraflora may not be older than Bajocian; Gliscopollis, which is frequent in some of the here described microfloral associations, was never registered in Upper ]urassic or younger beds. Dictyopbyllidites mor- toni (prabably the spores of Tbaumatopteris ) is present in the material studied, but is unknown frorn beds younger than Middle ]urassic. Todisporites major is in the world register only known frorn Lower and Middle ]urassic deposits. Thus, from the combined evidence, a Middle ]urassic age is indicated by the microflora, confirming the age given on megafloristic grounds by Menéndez (1956).