The first detailed skull anatomy of the Muñoa's Pampas cat Leopardus munoai (Carnivora: Felidae) from Southern Brazil.

The Muñoa's Pampas cat (Leopardus munoai) is a small wild cat endemic to the Uruguayan Savana ecoregion, occurring in southernmost Brazil, Uruguay, and northeastern Argentina. However, knowledge regarding the basic characteristics of this threatened species, including its cranial anatomy, is limited. This study presents the first detailed osteological description of the L. munoai skull and compares it, based on literature, with other species, particularly within the genus Leopardus. Additionally, we examined some internal cranial structures via computed tomography. Fourteen L. munoai specimens from Brazilian collections were analyzed. Key features observed include a minimally developed sagittal crest, the presence of the second upper premolar (P2) in most specimens, rostral zygomatic arches with slight lateral expansions, reduced mastoid processes, and an inverted "V"-shaped medial notch on the caudal margin of the palatine suture. Internally, trapezoidal frontal sinuses located at the postorbital process level were noted without extension into this region. A cavity was also identified at the rostral skull end bordered by the nasal and tubular structures extending laterally through the parietals. This study provides novel data on L. munoai, offering a detailed description of the external and internal structures and adding morphometric measurements for pampas cats from Rio Grande do Sul. Furthermore, it supports future osteological, morphometric, and taxonomic studies within Felidae.