Morphology of the megaspore Lagenoisporites magnus (Chi and Hills 1976) Candilier et al. (1982), from the Carboniferous (lower Mississippian: mid-upper Tournaisian) of Bolivia

Abstract

the morphology and structure of megaspores assigned to Lagenoisporites magnus from the toregua Formation, retama Group, mid-upper tournaisian of Bolivia were studied. the analysis was performed with light, fluorescence and scanning electron microscopy. Megaspores were laterally compressed and presented a spherical body with a proximal gula, of the hologula type. Gula had verrucae ornamentation and the spore body presented complex processes consisting of a bulbous base and an internally partitioned projection with sharp apex. In addition to this main ornamentation, perforations were present throughout the spore surface. Megaspores showed well marked curvaturae perfectae due to the abrupt transition existing between the gula ornamentation and the spore body processes. these megaspores were assigned to heterosporous arborescent lycopsids of the Lepidocarpaceae family, as in section view, exospore structure presented a three-dimensional network of fused elements. Likewise, due to a similarity found between sporoderm and Isoetes L. structure, it is evident that megaspores structure has remained intact inside the heterosporous lycopsids. therefore; the L. magnus structure not only would confirm its affinity with the Lycophyta fossils but also with the living ones.

SEM Observation of Non-Metallized Samples in Paleopalynology

“…Therefore, it is not possible to carry out more studies of the same specimens with other methods after SEM analyses. Some equipments allow the observation of nonconductive materials without metallization using low vacuum (LV) technique with a slight loss in the sharpness of the images compared to the HV ones [10,11]. Considering the specimens are preserved free of contaminants it is a minor loss.…”

“…The palynomorphs were recovered from the organic residue manually (picking) and temporarily mounted in a slide (with water media) to be pictured in a biological microscope with white and fluorescent lights. After, the specimens were transferred to a small glasss lide that is wrapped in a foil adhered to the stub [11,12]. All images obtained (Figs.…”