Resumo

ERRA, Georgina. Systematic assignation and paleocommunities inferred by a phytolite study of quaternary sediments from Entre Ríos, Argentina. Bol. Soc. Argent. Bot. [online]. 2010, vol.45, n.3-4, pp.309-319. ISSN 1851-2372.

Phytolith analysis is one of the paleobotanic disciplines used for the reconstruction of past ecosystems, because they provide a precise record of part of the vegetation for a specific time and place. In this context, the composition and variability of phytoliths in Quaternary loessic sediments from the Tezanos Pinto Formation in southwestern Entre Ríos province was studied. The data obtained allowed characterizing the paleocommunity that existed at the time when the loessic sediments were deposited. The found forms correspond to microphytoliths and to macrophytoliths, being of the bilobate and polylobate type (described for Poaceae subfamily Panicoideae), saddle type (subfamily Chloridoideae) and conical or rondel type (subfamily Pooideae). Also they were found phytoliths originated from hooks, prickles and macrohairs, from bulliforms cells and of long cells (all cellular types of epidermal origin of poaceae without diagnostic aptitude to differentiate subfamilies), and others produced for taxons non-grasses (echinate sphere) originated from the Arecaceae family.

Palavras-chave : Phytoliths; Grasses; Quaternary.

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