Redescription and reassignment of Entrerrioxylon victoriensis from the Upper Miocene, Paraná Formation, South America

Abstract

A new study of Entrerrioxylon victoriensis Lutz, 1981 has revealed that this taxon possesses many anatomical characteristics associated with the Caesalpinioideae, especially with the tribe Detarieae s.l. This paper redescribes and reassigns this specimen recovered from the upper Miocene Paraná Formation in the province of Entre Ríos, Argentina. The combined presence of intercellular axial canals, crystals in ray cells, partially storied rays and fiber walls with similar thicknesses was the diagnostic characteristics that support its transfer to the tribe Detarieae s.l. The discovery of this legume wood in southern South America also supports the existence of an old relationship with the African flora and close links with Central America and tropical South America. Also, many of the characteristics observed in Entrerrioxylon victoriensis could be used as indicators of wet tropical conditions.