Bianca Martins Mastrantonio

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.

Prestosuchus chiniquensis is an iconic non‐crocodylomorph loricatan from the Brazilian Triassic beds and the best‐known taxon, represented by several specimens. The completeness and preservation of its skeleton make it a valuable taxon for paleobiological studies. We explore the microstructure of bone tissues of appendicular elements and ribs of three specimens of Prestosuchus to access a variety of aspects of its paleobiology, such as histovariability, ontogeny, and growth patterns. Integrating our data and other osteohistologically studied P. chiniquensis specimens, we proposed for the first time an ontogenetic model for non‐crocodylomorph loricatans. The model encompasses six distinct age classes (I–VI) that allow us to infer the growth patterns of P. chiniquensis and possibly expand to other phylogenetically close taxa. During early ontogeny (age classes I–II), sustained fast growth was maintained by a fibrolamellar complex. In mid ontogeny (age classes III–IV), highly vascularized parallel‐fibered bone predominates, suggesting intermediary growth rates. A change for a poorly vascularized parallel‐fibered/lamellar bone would mark the attainment of sexual (age classes IV–V) and skeletal maturity, comprising the age class VI. An external fundamental system (EFS) present in the outermost cortex is the main histological feature that characterize the age class VI. Major histovariability features are present between appendicular bones and ribs of skeletally immature individuals. The most prominent of them is the presence of fibrolamellar complex and highly vascularized parallel‐fibered bone in appendicular bones and poorly vascularized parallel‐fibered bone in ribs. In advanced ontogenetic stages, the histovariability between appendicular bones and ribs tends to be minor. Our data also support previous hypothesis of the presence of one new taxon among the specimens assigned to P. chiniquensis, increasing the diversity of non‐crocodylomorph loricatans. The new taxon, represented by the specimen UFRGS‐PV‐0152‐T, awaits a formal anatomical description. Our study advances the preliminary understand of the ontogeny and growth patterns of non‐crocodylomorphs loricatans and Pseudosuchia as a whole.

Prestosuchus chiniquensis is the best represented pseudosuchian archosaur from the Pinheiros‐Chiniquá Sequence, Middle‐Late Triassic (Ladinian/Carnian) of the Santa Maria Supersequence, Southern Brazil. Several incomplete specimens attributed to this species have been described, but the morphology of the postcranial skeleton of P. chiniquensis is poorly known. In this contribution we present the postcranial material of the UFRGS‐PV‐0629‐T specimen, concluding its description, as its skull and endocast have already been described. Additionally, histological data provided new information on the poorly known ontogenetic series of P. chiniquensis, and on its growth patterns suggesting a longer period of slow growth when compared to other basal Loricata species. A phylogenetic analysis placed UFRGS‐PV‐0629‐T in a group composed by the lectotype, paralectotype, and other described P. chiniquensis specimens, further corroborating our taxonomic hypothesis, that specimens of basal Loricata collected in Brazil are closely related to each other. Due to the association of characters found in the phylogenetic analysis, the specimen UFRGS‐PV‐0629‐T is attributed as the most complete material ever found for P. chiniquensis. As such, it is clear that the material presented here provides important new information on P. chiniquensis. Based on the results presented here, we revised the diagnosis for P. chiniquensis. However, it also evidences the need for new discoveries and studies of other specimens seeking to understand this and other closely related species, which were important components of worldwide trophic webs of the Triassic biotas.

Publicado em 31 de julho de 2023. Composto por estudos científicos que perpassam o contexto clínico veterinário, o livro eletrônico que estás prestes a ler é fruto de um trabalho coletivo cujo intuito principal é explorar e descrever determinados temas de enorme importância aos profissionais dos seres vivos, especialmente médicos veterinários, zootecnistas e biólogos. Esses artigos vêm disponibilizar conhecimentos indispensáveis para os profissionais das ciências agrárias e biológicas, trazendo em suas páginas assuntos relevantes e atuais para atualização dos inúmeros trabalhadores qualificados que estão participando do desenvolvimento do agronegócio e da manutenção do meio ambiente brasileiro. Além disso, o presente e-book explora tanto assuntos de natureza fisiológica, quanto anatômica e ecológica, principalmente para reunir, de forma completa e objetiva, assuntos valiosos que enriquecerão ainda mais o seu conhecimento, querido leitor. Diante disso, acreditamos que cada trabalho científico lhe será de enorme utilidade conceitual e prática, principalmente para aprimorar e ampliar ainda mais sua expertise relacionada aos animais. Boa leitura! Organizadores: Alécio Matos Pereira Gilcyvan Costa de Sousa João Evangelista de Oliveira Filho