Primer registro de maderas gimnospérmicas de la Formación Roca Blanca (Jurásico Inferior), provincia de Santa Cruz, Argentina

three fossil wood species are recognised from the liassic (sinemurian- toarcian) roca blanca formation: agathoxylon protoaraucana (brea) gnaedinger and herbst nov. comb., prototaxoxylon pintadense gnaedinger and baieroxylon sp. cf. b. chilensis torres and philippe. for their secondary anatomical structures these species have close affinities with the coniferales (araucariaceae), taxales and ginkgoales? respectively. also, comparisons of agathoxylon protoaraucana (brea) gnaedinger and herbst and extant araucaria araucana (molina) k. koch showed that both have identical anatomical characters, which suggests a very conservative group.