On the squamation of Australerpeton cosgriffi Barberena, a temnospondyl amphibian from the Upper Permian of Brazil

Abdominal scales of a juvenile specimen of Australerpeton cosgriffi Barberena 1998 are made of primary compact bone rich in osteocyte lacunae; vascular canals and primary osteons are rare with no sign of remodelling of the tissue by resorption and redeposition. In contrast, the abdominal scales of an adult of the same species shows extensive reworking of the bone tissue. The scale grows by apposition of lamellar bone peripherally around the whole scale; the presence of Sharpey fibers in the periphery of the scales both basally and externally suggests that they remained deeply embedded in the dermis; the embryonic scale is completely remodelled in the adult by resorption and redeposition which produces a cancellous bone with large erosion bays and secondary osteons. Remodelling by resorption and redeposition is confined to the core of the scales and does not affect its periphery, contrary to what happens in sarcopterygians with cosmoid scales. The possible biological functions of the squamation in this species, such as mechanical protection, dry protection, cutaneous respiration, hydrostatic control and calcium reservoir, are discussed

A new Xenacanthiformes shark (Chondrichthyes, Elasmobranchii) from the Late Paleozoic Rio do Rasto Formation (Paraná Basin), Southern Brazil

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

The Eocene armadillo Utaetus buccatus (Euphractinae) in the Guabirotuba Formation (Curitiba Basin) and carapace morphological implications

The Guabirotuba Formation belongs to a small sedimentary basin located in the southernmost portion of the Cenozoic continental rift system of southeastern Brazil. In this unit was recognized the Guabirotuba Fauna from Eocene, that includes several cingulates such as Machlydotherium, Proeocoleophorus, Parutaetus, Meteutatus, Utaetus and an indeterminated Astegotheriini. The genus Utaetus in the Guabirotuba Fauna is confirmed by presence of Utaetus buccatus based on the specimen MCN.P.1231 and reinforce the Barrancan Age for the Guabirotuba Formation. In this study we analyzed numerous osteoderms associated to an individual, representing most of the external morphological diversity among fixed, semi-movable and movable osteoderms. Morphological features are described for fixed and movable osteoderms as well as, for the first time, for the semi-movable osteoderms. Features of some semi-movable osteoderms indicate the presence of some kind of pectoral buckler on Utaetus buccatus. The known geographic distribution of the genus Utaetus includes Argentinian Patagonia, Northwest of Argentina, and South of Brazil. The geographic distribution of the species Utaetus buccatus, previously restricted to Argentinian Patagonia, is here expanded to lower latitudes during the middle Eocene, which allow to infer that the species distribution was wider than previously thought.Fil: Sedor, Fernando A.. Universidade Federal do Paraná; BrasilFil: Klimeck, Tabata D. F.. Universidade Federal do Paraná; BrasilFil: Dias, Eliseu V.. Universidade Estadual Do Oeste Do Pará; BrasilFil: Oliveira, Edison V.. Universidade Federal de Pernambuco; BrasilFil: Ciancio, Martin Ricardo. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Laboratorio de Morfologia Evolutiva y Desarrollo.; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Vieira, Kimberlym T. P.. Universidade Federal do Paraná; BrasilFil: Fernandes, Luiz A.. Universidade Federal do Paraná; BrasilFil: Angulo, Rodolfo Jose. Universidade Federal do Paraná; Brasi

Seletividade fisiológica de inseticidas a Vespidae predadores de Ascia monuste orseis Insecticide physiological selectivity to Vespidae predators of Ascia monuste orseis

Este trabalho objetivou estudar a seletividade dos inseticidas carbaril, deltametrina, paratiom metílico, permetrina e triclorfom em relação a Ascia monuste orseis (Godart) (Lepidoptera: Pieridae) e a seus predadores Brachygastra lecheguana Latreille e Protonectarina sylveirae (Saussure) (Hymenoptera: Vespidae). Por meio de curvas de concentração-mortalidade e das concentrações letais para 90% da população (CL90), calcularam-se os índices de seletividade diferencial (ISD90), de toxicidade relativa, e de tolerância relativa (ITRe90). O paratiom metílico e triclorfom apresentaram seletividade em favor de B. lecheguana (ISD90 = 2,83 e 1,75) e P. sylveirae (ISD90 = 2,95 e 3,59) em relação a A. monuste orseis. Deltametrina e permetrina apresentaram seletividade em favor de P. sylveirae (ISD90 = 1,98 e 2,70) em relação a A. monuste orseis, mas não apresentaram seletividade em favor de B. lecheguana (ISD90 = 0,21 e 0,64). B. lecheguana foi menos tolerante a deltametrina, permetrina e triclorfom do que P. sylveirae (ITRe90 = 9,36, 4,23 e 2,05), e mais tolerante ao carbaril (ITRe90 = 0,14). Os predadores apresentaram tolerância semelhante ao paratiom metílico (ITRe90 = 1,04). As curvas de concentração-mortalidade do carbaril, permetrina e triclorfom em ambos os predadores, de deltametrina em B. lecheguana, e de paratiom metílico em P. sylveirae, apresentaram maiores inclinações do que as curvas em A. monuste orseis.<br>This work aimed to study the selectivity of the insecticides carbaryl, deltamethrin, methyl parathion, permethrin and trichlorfon in relation to Ascia monuste orseis (Godart) (Lepidoptera: Pieridae) and to their predators Brachygastra lecheguana Latreille and Protonectarina sylveirae (Saussure) (Hymenoptera: Vespidae). Based on concentration-response curves and lethal concentrations for 90% of the population (LC90), the differential selectivity index (DSI90), relative toxicity index and relative tolerance index (ReTI90) were calculated. Methyl parathion and trichlorfon were selective to B. lecheguana (DSI90 = 2.83 and 1.75) and P. sylveirae (DSI90 = 2.95 and 3.59) against A. monuste orseis. Deltamethrin and permethrin were selective to P. sylveirae (DSI90 = 1.98 and 2.70) against A. monuste orseis, but weren't selective to B. lecheguana (DSI90 = 0.21 and 0.64). B. lecheguana was less tolerant to deltamethrin, permethrin and trichlorfon than P. sylveirae (ReTI90 = 9.36, 4.23 and 2.05), but the opposite was observed to carbaryl (ReTI90 = 0.14). These two predators showed similar tolerance to methyl parathion (ReTI90 = 1.04). Concentration-response curves of carbaryl, permethrin and trichlorfon to both predators, deltamethrin to B. lecheguana, and methyl parathion to P. sylveirae, showed greater slopes than these curves to A. monuste orseis