Soledad RamosIAWA et al. Journal– Pleistocene 35 (2), Peltophoroxylon 2014: 199–212 from Argentina 199 A NEW FOSSIL WOOD OF PELTOpHOROXYLON (LEGUMINOSaE: CaESaLPINIOIDEaE) FROM THE EL PaLMaR FORMaTION (LaTE PLEISTOcENE), ENTRE RÍOS, ARGENTINa R. Soledad Ramos1,2,*, Mariana Brea1,3 and Romina Pardo4 1Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción (CICyTTP- CONICET), Dr. Matteri y España SN, E3105BWA, Diamante, Entre Ríos, Argentina 2FONCyT - Agencia Nacional de Promoción Científica y Tecnológica 3CONICET - Consejo Nacional de Investigaciones Científicas y Técnicas 4Cátedra de Dasonomía, Facultad de Ciencias Naturales, Universidad Nacional de Salta, Avenida Bolivia 5150, 4400 Salta, Argentina *Corresponding author; e-mail:
[email protected] abstract This paper describes the first record ofPeltophoroxylon (Ramanujam) Müller- Stoll et Mädel 1967 from the late Pleistocene of Argentina. The fossil specimens were recovered from the Colonia Ayuí and Punta Viracho fossil localities of the El Palmar Formation, located in the middle part of the Uruguay Basin, eastern Argentina. The diagnostic features are: growth ring boundaries demarcated by marginal parenchyma, medium-sized vestured intervessel pits, vessel-ray paren- chyma pits similar in size and shape to intervessel pits, vasicentric to lozenge type aliform axial parenchyma, biseriate (70%) and uniseriate (30%) homocel- lular rays, non-septate and septate fibers, and long chains (10+) of prismatic crystals in chambered axial parenchyma cells. These features suggest a relation- ship with Peltophorum (Vogel) Benth. (Leguminosae: Caesalpinioideae). The vessel diameter and vessel density of the El Palmar woods are consistent with the temperate-warm, humid-semiarid climate inferred for this region during the late Pleistocene. Keywords: Wood anatomy, Peltophoroxylon, Pleistocene, Uruguay Basin, Argentina.