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

CARMEN CECILIA MACLUF; MARCELA QUETGLAS; MERCEDES DI PASQUO

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2019 vol. 91 p. 1 - 10

0001-3765

The morphology and structure of megaspores assigned to Lagenoisporites magnus from theToregua Formation, Retama Group, mid-upper Tournaisian of Bolivia were studied. The analysis wasperformed with light, fluorescence and scanning electron microscopy. Megaspores were laterallycompressed and presented a spherical body with a proximal gula, of the hologula type. Gula had verrucaeornamentation and the spore body presented complex processes consisting of a bulbous base and aninternally partitioned projection with sharp apex. In addition to this main ornamentation, perforations werepresent throughout the spore surface. Megaspores showed well marked curvaturae perfectae due to theabrupt transition existing between the gula ornamentation and the spore body processes. These megasporeswere 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 similarityfound between sporoderm and Isoetes L. structure, it is evident that megaspores structure has remainedintact inside the heterosporous lycopsids. Therefore; the L. magnus structure not only would confirm itsaffinity with the Lycophyta fossils but also with the living ones.