INVESTIGADORES
BALSEIRO Diego
congresos y reuniones científicas
Título:
A new anatomically preserved flora from the Mississippian of Sierra de Las Minitas (La Rioja, Argentina)
Autor/es:
PRESTIANNI, C.; RÚSTAN, J.J.; BALSEIRO, D.; VACCARI, N.E.; STERREN, A.F.; SFERCO, E.
Lugar:
Autun
Reunión:
Congreso; Agora Paleobotanica. Un hommage à / A tribute to Bernard Renault (1836-1904); 2015
Resumen:
A new anatomically preserved flora has been discovered in the Sierra de Las Minitas, a set of low mountains located approximately 30 km to the southwest of the small town of Jagüé, northernmost Precordillera, La Rioja Province, western Argentina. Fossils were collected from a virtually unexplored section, in a very complex stratigraphic and structural setting. Preserved inside nodules, plant remains come from an interval in a thick siliciclastic succession, mainly composed by yellowish to greenish shales and siltites, subordinated sandstone and conglomerate layers and diamictitic deposits. Brachiopods and corals in a number of levels indicate that marine deposits are at least partially represented. In addition, an exquisitely preserved fish assemblage has been identified associated with thefossil flora in similar nodules.Since the palaeontological survey of the area is still preliminar, fossils could not be referred to a formal stratigraphic unit. In turn, due to the absence of reliable biostratigraphic indicators and radiometric data, just a broad Mississippian age is interpreted for the fossil-bearing strata. Under progress, the study of the flora has revealed a diverse assemblage comprised of Lycopsids, Ferns (cladoxyls and zygopterids), seed plant rachises and stems. The Sierra de las Minitas deposits are complex and very likely record most of the Mississippian. They are particularly fossiliferous throughout the whole succession. Plant, fishes and invertebrates have been collected and record a strong climatic and ecological transition from cold to warm environments. Given the depauperate nature of previously known floras from the Mississippian of southern South America, these diverse anatomically preserved records may shed light on the ecological, biogeographical and evolutionary history of high latitude Gondwanan continental environments.