CONIFER FOSSIL WOODS FROM THE LATE JURASSIC–EARLY CRETACEOUS (SOLARI/BOTUCATÚ FORMATION) OF THE PARAJE TRES CERROS (CORRIENTES PROVINCE), NORTHEAST ARGENTINA

Abstract

An assemblage of 22 fossil woods was collected from sandstones of the Solari/Botucatú Formation, Late Jurassic–Early Cretaceous, at Paraje Tres Cerros, Corrientes Province, Argentina.  The preservation of most fossils is poor. However, twelve samples have radial pitting and a few cross-fields preserved. These characters allow the assignment of fossil woods to the Araucariaceae. All the fossils seem to be of the same taxonomic unit with the following main characteristics: growth ring boundaries distinct (poorly marked), intertracheary araucarian radial pitting, uni- to biseriate bordered pits, wide tracheids, araucarioid cross-field pitting, uniseriate rays, and absence of axial parenchyma and resin canals. The fossils were assigned to cf. Agathoxylon Hartig. The size of the fossil woods and the growth ring curvatures indicate that the samples were part of big trees. The width of the growth rings also indicates significant annual growth. The taxonomic assignment suggests that monospecific forests of Araucariaceae developed in the area. This is the record of the first Mesozoic fossil remains from the Corrientes Province.