Resumo

FRANCO, María Jimena. Soroceaxylon entrerriensis n.gen and n.sp. (Moraceae) from the Ituzaingó Formation (Plioceno-Pleistoceno), Paraná river basin, Argentina. Rev. mex. cienc. geol [online]. 2010, vol.27, n.3, pp.508-519. ISSN 2007-2902.

Fossil woods, found in the Pliocene-Pleistocene of Ituzaingó Formation (Paraná Basin, Argentina), are described and assigned to a new morphogenus with affinities with Moraceae family. The fossil woods have predominantly solitary vessels and in radial multiples of between two and nine elements and tangential multiple less common; very small and alternate intervessel pits; axial parenchyma scanty paratracheal, complete and incomplete and apotracheal axial parenchyma scanty and diffuse-in-aggregates; uniseriate and multiseriate rays, heterocellular rays, multiseriate rays with one to three channels probably laticifers or tanniniferous tubes and prismatic crystals in radial cells. The fossil woods are anatomically similar to the extant species ofthe genus Sorocea A. St. Hil. Moraceae probably originate in Eurasia with subsequent migration facilitated by multiple land routes. This record indicates that Moraceae were well established in the Pliocene-Pleistocene of South America.

Palavras-chave : Fossil woods; Moraceae; Ituzaingó Formation; Pliocene-Pleistocene; South America.