Article

Una nueva Podocarpácea fértil (Coniferal) del Cretácico inferior de Patagonia

AMEGHINIANA (Impact Factor: 1.22). 01/1990; 27(1).

ABSTRACT

The new genus, Morenoa fertilis from the early Cretaceous beds of the Baqueró Formation (Santa Cruz Province, Argentina) is here described. This conifer is referred to the family Podocarpaceae on account of its vegetative as well as reproductive male organs that include bisaccate pollen grains. The ultrastructure of the leaf cuticle (of the Elatocldus type) and the pollen grains (of the Podocarpidites type) was studied with transmission electron microscopy. Comparision with fossil and extant taxa of the family are also made, including the other three fossil genera known in fertile state from the same formation. The excellent preservation of the closed pollen sacs permitted the recognition of still inmature tetrads and a high inner content of Ubisch bodies. Epiphyllous fungi were also recognized on the leaf epidermis suggesting a mild and humid climatic regime.Some degradation of the leaf cuticles was observed, possibly related in part to fungal activity.

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    • "The studies on the fossil leaf cuticular ultrastructure using transmission electron microscopy started with the pioneer work of Archangelsky et al. (1986). Since then, the leaf cuticular ultrastructure is known for a number of fossil taxa or groups, including pteridosperms (Taylor et al., 1989; Baldoni and Barale, 1996; Labe and Barale, 1996; Maheshwari and Bajpai, 1996; Bajpai, 1997; Guignard et al., 2001), bennettitaleans (Barale and Baldoni, 1993; Villar de Seoane, 2001), cycadaleans (Artabe and Archangelsky, 1992; Villar de Seoane , 1997b), ginkgoaleans (Taylor et al., 1989; Villar de Seoane , 1997a; Guignard and Zhou, in press), czekanowskialeans (Zhou and Guignard, 1998), as well as conifers (Archangelsky and Taylor, 1986; Archangelsky et al., 1986; Del Fueyo et al., 1990; Barale et al., 1992; Guignard et al., 1998; Villar de Seoane, 1998; Zhou et al., 2000). Most of the cuticle is marked [Vol. "
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