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The study of two caves from the Serra do Ramalho region is here presented, this is one of the most important karstic areas in Brazil. A taxonomic analysis revealed 29 taxa including Xenarthra, Cetartiodactyla and Carnivora, ranging from Late Pleistocene to Early Holocene. Taphonomic studies reveal taphocoenosis consisting mainly of complete elements, without significant transportation, but also of transported elements, composing spatial-mixed, predominantly in situ-preserved assemblages. The predominance of Xenarthrans found within the caves is probably biased by a taphonomic pattern since these animals would have life habits related to cave environments, therefore with higher chances of preservation. There is evidence of accidental death of the scelidotheriines in Lapa dos Peixes cave, where entrapment of the animals during one or more events of river flooding is pointed as a hypothesis. Deposition took place within different periods of dry and humid climate incorporating bones in clastic and chemical deposits. Cycles of sedimentary deposition and reworking (erosion) may have acted in generating complex and overlapping depositional patterns with time averaging. During depositional phase, while the cave environment was occupied rather by Xenarthrans, parts of other animals were transported in the scope of fluvial systems and gravity loads, as well as by accidental falling or scavengers. The sedimentary deposits are currently being eroded by rain runoff in both caves, causing the reallocation of finer sediments to deeper conduits but the fossils keep close to their original location. This process is exposing a large amount of fossils, allowing extensive sampling which would be impossible with active excavations, since it would require an excessively longer time and damages to the caves.

The Paleogene vertebrate-bearing sites of Brazil are restricted to few formations such as Maria Farinha (Late Cretaceous-early Paleocene), Itaborai (early Eocene), Entre-Corregos (Eocene-Oligocene), and Tremembe (late Oligocene-early Miocene). A new Paleogene fauna is reported from an outcrop of the Guabirotuba Formation located at Curitiba, Parana State, southern Brazil. The Guabirotuba Formation is a stratigraphic unit of the Curitiba Basin, which belongs to the Cenozoic continental rift system of southeastern Brazil, a predominantly half-graben and horst system. The sedimentary facies indicate a fluvial distributary depositional system associated with floodplain, generated under humid climate conditions alternating with drier periods. This new Paleogene fauna, here named the Guabirotuba Fauna, has invertebrate and vertebrate taxa, including mammals (Cingulata, Notoungulata, Astrapotheria, and Metatheria). The fossil remains of seven armored xenarthrans are identified, including the description of a new species and genus named Proeocoleophorus carlinii. The Guabirotuba ungulates are assigned to Interatheriidae, Oldfieldthomasiidae, and Astrapotheria. The metatherian mammals are represented by a sparassodont, a palaeothentoid, and an argyrolagoid. This new mammalian fauna preliminarily suggests a late middle Eocene age (Barrancan South American Land Mammal Age) for the Guabirotuba Formation.

Despite subaqueous fossils tracks of tetrapods being quite common in the fossil record, few studies discuss their classification and morphofunctional interpretation. Even with their simple morphology, some important information about the trackmakers can be retrieved from these tracks. Subaqueous traces were found in Brazil in the Irati Formation (Cisuralian, Permian), Paraná Basin, and described as Mesosaurichnium natans, related to Mesosauridae. The traces were produced in a shallow marine environment, whose substrate contained crustacean shells forming a thin layer. The mesosaurids produced the traces by swimming close to the bottom. The propulsion was provided by undulatory moves of the long tail, mainly for faster swimming. The feet could act as accessory and slower propellants, but provided more maneuverability.

The chondrichthyan skeletal structures with the greatest potential for fossilization are teeth, scales, fin and cephalic spines. In the Rio do Rasto Formation, the Chondrichthyes are represented by finspines and teeth attributed to sphenacanthids, hybodontids and xenacanthids. Herein is presented new finspines collected from an outcrop of the Serrinha Member of the Rio do Rasto Formation, in the Municipality of Jacarezinho, Parana State. The studied material consists of two finspines that are gradually tapered distally, with convex anterior and lateral faces. The posterior proximal face is strongly concave forming a furrow; absence of pronounced median ridge in the posterior distal face; the lateral faces have non-pectinated ribs separated by intercostal grooves, some of them bifurcated and beaded with rows of rounded closely spaced tubercles are the features that allow the finspines to be ascribed to a new species of Sphenacanthidae.

EQUUS (AMERHIPPUS) NEOGAEUS LUND, 1840 (PERISSODACTYLA, EQUIDAE) FROM THE QUATERNARY OF PARANA STATE, BRAZIL. The fossil record of Equidae in southern Brazil is restricted to Rio Grande do Sul State and is represented by isolated teeth and fragmentary cranial and postcranial remains. This paper describes Equus (Amerhippus) neogaeus Lund from Parana State, where Pleistocene mammals are poorly known. The material is a left dentary with cheek teeth and was found in the Mangueirinha Municipality in a small alluvial terrace, associated with some remains of Gomphoteriidae and Megatheriidae. The presence of E. (A.) neogaeus suggests an open paleoenvironment with xerofitic vegetation, and could indicate a Lujan Age/Stage (late Pleistocene/early Holocene) for the assemblage fauna.

Although Late Permian tetrapods are relatively common around the world, few taxa are known in rocks of this age in South America. So far, the study of the tetrapod paleofaunas in the Permian of Brazil has provided significant chronological data, though knowledge about them is still incipient. These studies generally take into account only body fossil records, but the ichnological record can provide new biostratigraphic elements for correlation. In Brazil, fossil tracks were first recorded in Rio do Rasto and Corumbatai Formations (Late Permian from Parana Basin), but to date these tracks have not been studied in an ichnotaxonomic, morphofunctional, paleoenvironmental and chronological context. The study of these tracks became possible due to a considerable increase in the number of taxa from the Late Permian of Brazil, including Chelichnus isp. (Synapsida: Caseidae?), Procolophonichnium isp. (Procolophonoidea), Rhynchosauroides gangresci isp. nov. (basal Diapsida), Dicynodontipus penugnu isp. nov. (Dicynodontia) and Incertae sedis (Amphibia?). With the exception of Dicynodontia, the remaining recorded taxa are unknown through fossil skeletons, showing that the Brazilian Permian faunas were much more diverse than was previously reported and demonstrating the potential of South American fossil vertebrates for global correlations.

The Brazilian records on Xenacanthiformes include teeth and cephalic spines from the Parnaíba, Amazonas and Paraná basins. This work describes a new species of Xenacanthidae, collected in an outcrop of Serrinha Member of Rio do Rasto Formation (Wordian to Wuchiapingian), Paraná Basin, municipality of Jacarezinho, State of Paraná. The teeth of the new species are two or three-cuspidated and the aboral surface show a smooth concavity and one rounded basal tubercle. The coronal surface presents one semi-spherical and subcircular coronal button, and also two lateral main cusps and one central (when present) with less than one fifth of the size of the lateral cusps in the labial portion. The lateral cusps are asymmetric or symmetric, rounded in transversal section, lanceolate in longitudinal section, devoid of lateral carinae and lateral serrations, and with few smooth cristae of enameloid. In optical microscope the teeth show a trabecular dentine (osteodentine) base, while the cusps are composed by orthodentine, and the pulp cavities are non-obliterated by trabecular dentine. The fossil assemblage in the same stratigraphical level and in the whole Rio do Rasto Formation indicates another freshwater record for xenacanthid sharks. O registro brasileiro dos Xenacanthiformes inclui dentes e espinhos cefálicos encontrados nas bacias do Parnaíba, Amazonas e Paraná. Este trabalho descreve uma nova espécie de Xenacanthidae, coletada em um afloramento do Membro Serrinha da Formação Rio do Rasto (Wordiano ao Wuchiapingiano), Bacia do Paraná, Município de Jacarezinho, Estado do Paraná. Os dentes da nova espécie são bi ou tricuspidados e a superfície aboral apresenta uma suave concavidade e um tubérculo basal arredondado. A superfície coronal apresenta um botão coronal semi-esférico e subcircular, além de duas cúspides laterais principais e uma central (quando presente) com menos de um quinto do tamanho das cúspides laterais em sua porção labial. As cúspides laterais são assimétricas ou simétricas, arredondadas em corte transversal, lanceoladas em corte longitudinal, carenas laterais e serrilhas laterais ausentes, e com suaves cristas de enamelóide. Em microscopia óptica os dentes apresentam base composta por dentina trabecular (osteodentina), enquanto que as cúspides são compostas por ortodentina, e os canais pulpares não são obliterados por dentina trabecular. A assembléia fóssil no mesmo nível estratigráfico e na Formação Rio do Rasto como um todo indica mais um registro de água doce para os tubarões xenacantídeos.