Floian chitinozoans (Lower Ordovician) from Santa Victoria area, Cordillera Oriental, northwestern Argentina. Systematics. Floian chitinozoans from the Acoite Formation outcropping in the La Huerta and Grande creeks in the Santa Victoria area, northestern end of the Argentinian Cordillera Oriental, in Salta Province are studied. The chitinozoans are calibrated according to the previously established graptolite zonation in the La Huerta stratigraphic section which includes the Tetragraptus akzharensis (latest early Floian), “Baltograptus deflexus” (latest middle Floian) and Didymograptellus bifidus (late Floian) zones, and the associated acritarch assemblages. Despite the fact that species identifications of chitinozoans are usually difficult to carry out because of the scarce and poorly preserved specimens, a fairly diverse assemblage is observed in the studied levels. Seven genera and 15 species are recognized. Of these genera, Rhabdochitina, Velatachitina and Siphonochitina are described for the first time in Agentina. Ten species are described for the first time in Argentina. Lagenochitina sp. A and Eremochitina sp. A are local species exlusively recorded in northwestern Argentina.