The dinocephalians (Synapsida, Therapsida) were one of the dominant tetrapod groups of the Middle Permian (Guadalupian Epoch, ~270-260 million years ago) and are most abundantly recorded in the Tapinocephalus Assemblage Zone (AZ) of the Main Karoo Basin, South Africa. Dinocephalians are thought to have become extinct near the top of the Abrahamskraal Formation of the Beaufort Group and their disappearance is one criterion used to define the base of the overlying Pristerognathus AZ. Because of the abundance of fossils in the Karoo, the Beaufort Group biozones form the biostratigraphic standard for later Permian terrestrial tetrapod ecosystems, so their stratigraphic delineation is of great importance to Permian palaeobiology. We report two new specimens of the rare tapinocephalid dinocephalian Criocephalosaurus from the lowermost Poortjie Member, which makes them the youngest dinocephalians known from the Main Karoo Basin and extends the Tapinocephalus AZ from the Abrahamskraal Formation up into the Teekloof Formation. The extension of the Tapinocephalus AZ relative to the lithostratigraphy potentially affects the biozone or biozones to which a fossil species can be attributed; this extension has implications for biostratigraphic correlations within the Main Karoo Basin as well as with other basins across Gondwana. These discoveries also indicate that a population of herbivorous tapinocephalids survived as rare constituents of the tetrapod fauna after most generic richness within the clade had already been lost.

OBJETIVO: Verificar a geometria do fêmur da população brasileira por meio de estudo radiográfico e correlacionar os valores quanto ao sexo e ao lado direito/esquerdo.MÉTODOS: Foram analisadas 500 radiografias anteroposteriores de bacia de pacientes esqueleticamente maduros, 250 de cada sexo, sem a presença de osteoartrose, fraturas e lesões tumorais ou infecciosas. Foram mensurados os valores do comprimento e da largura do colo do fêmur, do eixo femoral, do ângulo colodiafisário e do offset femoral.RESULTADOS: Observou-se uma média de 36,54 mm do comprimento do colo do fêmur, 37,48 mm da largura do colo do fêmur, 108,42 mm do comprimento do eixo femoral, 130,47° do ângulo colodiafisário e 44,4 mm do offset femoral.CONCLUSÃO: Os valores médios das principais medidas do fêmur proximal dos brasileiros diferem de trabalhos prévios. Foi possível evidenciar também que existe diferença média estatisticamente significante entre homens e mulheres para todas as variáveis, tanto do lado esquerdo quanto do direito, e que os homens tiveram média maior do que as mulheres.

OBJECTIVE: To ascertain the geometry of the femur in the Brazilian population by means of a radiographic study and to correlate the values with regard to sex and right/left side.METHODS: Five hundred anteroposterior radiographs of the pelvis of skeletally mature patients (250 of each sex) who did not present any osteoarthrosis, fractures or tumoral or infectious lesions were analyzed. The length and width of the femoral neck, length of the femoral axis, neck-shaft angle and femoral offset were measured.RESULTS: The following means were observed: 36.54 mm for the length of the femoral neck; 37.48 mm for the width of the femoral neck; 108.42 mm for the length of the femoral axis; 130.47° for the neck-shaft angle; and 44.4 mm for the femoral offset.CONCLUSION: The mean values for the main measurements on the proximal femur in Brazilians differed from those of previous studies. It could also be shown that there was a statistically significant mean difference between men and women for all the variables, both on the left and on the right side, and that the men had greater means than the women.

We document the bone microstructure of traversodontids from Argentina and Brazil and make detailed comparisons of the bone microstructure of these cynodonts with that of other traversodontids, nonmammaliaform therapsids (including cynodonts), and Mesozoic mammalian taxa. Our analysis provides information on traversodontid ontogenetic age, growth patterns and life-style adaptations. The osteohistological data derived from the current study, as well as data on other nonmammaliaform cynodonts, provide an understanding of the evolution of life-history patterns among the therapsids. We show that many of the nonmammaliaform cynodonts (including some traversodontids) formed bone at rapid rates but retained flexible developmental growth patterns. In addition, although we observe a trend of increasingly rapid osteogenesis among the traversodontids, our findings do not discern a particular bone tissue type as a synapomorphy of the clade. This reinforces earlier hypotheses that the microscopic structure of bone is influenced by several intrinsic and extrinsic factors, and is not constrained by phylogeny alone.