Rare evidence for 'gnawing-like' behavior in a small-bodied theropod dinosaur.

Mammalian carnivores show a higher degree of prey bone utilization relative to non-avian theropod dinosaurs, with this major ecological difference reflected in the frequency and morphology of tooth marks in modern and Cenozoic assemblages relative to Mesozoic ones. As such, prey bone utilization (i.e., gnawing, bone-breaking, osteophagy) may represent a key ecological strategy repeatedly exploited by mammalian carnivores but rarely in theropod dinosaurs. Here we describe an isolated adult-sized hadrosaurid pedal ungual (III-4) from the Dinosaur Park Formation (Campanian) of southern Alberta which shows a unique pattern of bite marks from a small- to medium-sized theropod dinosaur. Thirteen distinct tooth marks occur in a restricted area of the ungual, and the pattern suggests up to six repeated, high-power bites delivered to the bone. The tracemaker cannot be definitively identified, but was likely a dromaeosaurid or very young tyrannosaurid. Tooth marks on at least four other Dinosaur Park Formation hadrosaur pedal unguals are reported, but the overall frequency of occurrence in unguals (< 1%) is much lower than that reported for other bones. The pattern of tooth marks on this specimen deviates from most described theropods tooth marks, and given the low volume of meat associated with the ungual, may represent theropod prey bone utilization as part of late-stage carcass consumption, and a behavior similar to mammalian gnawing.

Deficiência de fósforo em caprinos no semiárido de Pernambuco / Phosphorus deficiency in goats in the semiarid region of Pernambuco, Brazil

O objetivo deste estudo foi avaliar os aspectos clínicos e patológicos da deficiência de fósforo em caprinos no semiárido de Pernambuco. Para isso, visitas técnicas foram realizadas em diferentes propriedades na microrregião do Sertão do Moxotó durante o período da estação seca. Realizaram-se exames clínicos, determinação da atividade sérica de cálcio total e ionizado, fosforo sérico, magnésio, razão Ca:P, proteína total, albumina, globulina e o percentual de cinzas ósseas. Biopsias ósseas da região hipocondríaca da 12 costela direita foram fixadas em solução de formalina a 10% e descalcificadas para análises histológicas. Os principais sinais clínicos observados nos caprinos com deficiência de fósforo foram aumento da fragilidade óssea além de desidratação, magreza, hipomotilidade ruminal, alopecia, pelos opacos, quebradiços e eriçados e osteofagia. As médias dos valores das cinzas ósseas e do teor de fósforo nos ossos estavam abaixo dos valores de referência e a correlação entre essas duas variáveis foi fortemente positiva (r=0,91); a redução da concentração do fósforo sérico foi acompanhada da redução da porcentagem desse mineral nas cinzas. Esse resultado é conclusivo para o diagnóstico de deficiência de fósforo. No exame microscópico dos fragmentos ósseos das costelas, verificou-se evidente aumento da atividade osteoclástica com áreas de reabsorção óssea e maior quantidade de tecido osteóide e de fibras colágenas na matriz óssea. Conclui-se que a deficiência de fósforo é uma doença frequente em caprinos criados em regime semi-extensivo no semiárido de Pernambuco e que a suplementação desse mineral é necessária na região estudada.(AU)

The aim of this study was to evaluate the clinical and pathological aspects of phosphorus deficiency in goats in the semiarid region of Pernambuco. For this, technical visits were carried out at different properties in the Sertão do Moxotó region during the dry season period. Clinical examinations, serum analysis and rib biopsies were carried out to determine macromineral contents. Serum concentrations of total and ionized Ca, serum and bone P, Mg, Ca:P ratio, total protein, albumin, globulin and ashes were determined. Bone biopsies were performed by surgical procedure in the hypochondriac region of the 12th right rib which were fixed in 10% formalin solution and decalcified for histological analysis. The main clinical signs in phosphorus-deficient goats consisted of dehydration, poor corporal score, ruminal hypomotility, alopecia, opaque, brittle and bristly hair and osteophagy. The averages of bone ashes and phosphorus content in bones were below the reference values and the correlation between these two variables was strongly positive (r=0.91). The reduction of the serum phosphorus concentration was accompanied by the reduction of the percentage of this mineral in the ashes. This result is conclusive for the diagnosis of phosphorus deficiency. In the microscopic examination of ribs bony fragments there was a clear increase in osteoclastic activity with areas of bone resorption and a greater amount of osteoid tissue and collagen fibers in the bone matrix. It is concluded that phosphorus deficiency is a frequent disease in goats in the semiarid region of Pernambuco, Brazil and and the supplementation of this mineral is necessary in the studied region.(AU)