The distribution of species, which is the main aim of this catalogue (see Introduction for the difference between this catalogue and the World Spider Catalog), cannot be complete without those species that have uncertain taxonomic and biogeographic status (Uncertain species) or those species that, although not native, have made the Andean tropical countries their new home (of course with human help), since they are now introduced from other regions of the world to the ArachnoTrAC region (Introduced species).

In this sense, you can enter each box bellow with the list of species officially registered in the scientific literature for each of the orders of arachnids in the ArachnoTrAC region, or in the lists of introduced species or uncertain species! 

In Statistics you can find some of the most interesting numbers and statistics we're finding on the diversity and distribution of Arachnids in the Tropical Andean Countries (#arachnotrac)!