BECAS
QUETGLAS Marcela Alejandra
artículos
Título:
Re-examination/New contribution of in situ spores of petrified lycopsid cone Cylostrobus ornatus (Morbelli and Petriella) Retallack of South America
Autor/es:
MARCELA QUETGLAS; CARMEN CECILIA MACLUF; ELIANA COTUREL
Revista:
REVIEW OF PALAEOBOTANY AND PALYNOLOGY
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2022 vol. 309 p. 1 - 9
ISSN:
0034-6667
Resumen:
Megaspores and microspores belonging to Cylostrobus ornatus, a fragment of a petrified cone, from the Laguna Colorada Formation (Norian) of Santa Cruz province, Argentina, were re-study to make more detailed descriptions and to compare them with spores of fossil and extant lycopsids to broaden the knowledge on the botanical affinity of heterosporous lycopsids. To achieve this goal, spores were observed with both stereoscopic and light microscopes. In addition, to study the sporoderm ultrastructure, megaspores could also be observed in detail with scanning electron microscopy. The similarity of the sporoderm arrangement of Cylostrobus ornatus megaspores and microspores with both fossil and extant lycopsids plus the existence of laminated zones in the periapertural region of the studied megaspores, indicated a botanical affinity with Isoetalean, less possibly, to Selaginellalean. Thus confirming the hypothesis of stasis in the lycopsids wall and therefore, the conservative nature of the wall formation, which would have persisted relatively unchanged within the heterosporous lycopsids.
