Evolutionary biogeography aims to provide a hierarchical system of biotic regionalisation for areas of the Earth that correspond to natural areas related by their common evolutionary history. In this context, the central Pampean Ranges of Argentina, formed by the mountain systems of Córdoba and San Luis, are immersed in the Chacoan dominion; however, higher-altitude environments of these mountains, namely highland grasslands and tabaquillo forests, have relationships with the Andean region and other Neotropical areas that are different from the Chacoan dominion, which would indicate that the current classification would not be natural. To clarify their biogeographic relationships, a track analysis of the distribution of the biota of vertebrates and vascular plants of the highland grasslands and tabaquillo forests of central Pampean Argentinian Ranges was conducted. The obtained distributional patterns suggest that the area under study has diverse geobiotic origins, both Andean and Neotropical, indicating that, in this area, an interaction of biota with different evolutionary origins occurs; so, its status as a biogeographic province is proposed, belonging to the South American transition zone. [ABSTRACT FROM AUTHOR]