1 September 2012 Terminalia palaeopubescens sp. nov. (Combretaceae) da Formação Fonseca (Eoceno/Oligoceno) de Minas Gerais, Brasil: Morfologia Foliar, Fungos Epifilicos Associados e Paleoclima
Jean Carlo Mari Fanton, Fresia Ricardi-Branco, Adalene Moreira Silva
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TERMINALIA PALAEOPUBESCENS NOV. SP. (COMBRETACEAE), FROM THE FONSECA FORMATION (EOCENE/ OLIGOCENE), MINAS GERAIS STATE, BRAZIL: LEAF ARCHITECTURE, EPYPHYLLOUS FUNGI AND PALEOCLIMATE. In this study, well-preserved leaf-blade compressions and impressions from shale levels in the Fonseca Formation (Priabonian/Rupelian of the Fonseca Basin, state of Minas Gerais, southeastern Brazil) and associated epiphyllous fungi are described. Based on leaf architecture and indumentum, a new species is established, assigned to the extant tropical genus Terminalia L. (Combretaceae). The leaf of Terminalia palaeopubescens sp. nov. is mesophyll, narrow obovate and with an entire margin. Its secondary veins are camptodromous-brochidodromous, the tertiary pattern is percurrent mixed predominantly alternate, the quaternaries are alternate percurrent and the higher orders regular polygonal reticulate, with small and well developed areoles. Trichomes are present in the indumentum and are simple, slender, pointed, and with a swollen base, typical of the Combretaceae. Epyphyllous fungi, in the shape of microthyrioid disks of variable size and profusely colonizing the leaf surface, were assigned to Callimothallus Dilcher (Microthyriaceae). The presence of those biogenic structures (besides Phragmothyrites Edwards, already reported in the same levels of the Fonseca Formation) indicates that a prominent leaf mycoflora was associated to the vegetation, probably sustained by warm and humid conditions. The data here presented, analyzed together with other taxonomic, taphonomic and foliar physiognomic indicators, lead to the hypothesis that a dense rainforest, supported by heavy rainfall and high temperatures, was thriving near the banks and floodplain environments associated to fluvial systems of the Fonseca Formation, during the Eocene/Oligocene transition, in southeastern Brazil.

Jean Carlo Mari Fanton, Fresia Ricardi-Branco, and Adalene Moreira Silva "Terminalia palaeopubescens sp. nov. (Combretaceae) da Formação Fonseca (Eoceno/Oligoceno) de Minas Gerais, Brasil: Morfologia Foliar, Fungos Epifilicos Associados e Paleoclima," Ameghiniana 49(3), 273-288, (1 September 2012). https://doi.org/10.5710/AMGH.v49i3(344)
Received: 26 May 2010; Accepted: 1 July 2011; Published: 1 September 2012
Eocene/ Oligocene
Eoceno/ Oligoceno
Epiphyllous fungi
Folhas fósseis
Fonseca Formation
Formação Fonseca
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