- authors of manuscript submitted to Zoologia entitled: Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil. Authored by: Walter A Boeger, Michel P Valim, Hussam Zaher, José Albertino Rafael, Rafaela Campostrini Forzza, Alexandre R Percequillo, Cristiana S Serejo, and Brazilian Zoology Group 2023 (BZG 2023). Abstract: The reduced temporal validity of species lists made available in a traditional manner in scientific publications has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent the up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is not an exception and the Catálogo Taxonômico da Fauna do Brasil (CTFB), made public in 2015, presents a list of valid and expertly recognized scientific names of animals in Brazil which is updated in real time. By December 10th, 2023, the CTFB compiled 125,138 valid nominal species names, the result of the collaborative work of more than 600 specialists. Most species are arthropods (82.3% with more than 102,000 species) and chordates (7.69% with over 11,000 species). These taxa are followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups have less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species), representing those with more than 500 species. Analysis of the CTFB database can facilitate and orient efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best-available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature of diverse areas of biology, law, anthropology, education, forensic science, and veterinary, among others. Catálogo Taxonômico da Fauna do Brasil (CTFB) - link: http://fauna.jbrj.gov.br/fauna