New genus and species of liane from the Upper Miocene (Palo Pintado Formation), Salta Province, Argentina

Ranunculodendron anzoteguiae, a new genus and species of fossil liane from the Upper Miocene Palo Pintado Formation of Salta Province, Argentina is described. It is a circular liane, 4 mm in diameter, externally ribbed. The pith is excentric, whith 4 protoxilem vessels and secondary xylem divided into wedges by parenchymatous rays, all surrounded by cambium, phloern and cortex. The histological characters were compared with those of Lardizabalaceae and Menispermaceae (Order Ranunculales). Comparisons with other fossil lianes: Lardizabaloxylon lardizabaloides Shonfeld, Vitaceoxylon ranunculiformis Poole and Wilkinson and Menispermoxylon sp. of Vozenin-Serra et al. were also made. Geological, palynological and megafloral data are discussed in order to infer the paleoclimatic conditions in which the lianes inhabited.