Early Cretaceous Mammal Research Articles

First Mesozoic mammal from Australia—an early Cretaceous monotreme

Here we describe Australia's first known Mesozoic mammal and the first known early Cretaceous mammal from Gondwanaland. Steropodon galmani n. gen. and sp., discovered in early Cretaceous sediments at Lightning Ridge, New South Wales, Australia, appears to represent an ornithorhynchid-like monotreme. This discovery represents the first record of a fossil mammal from Australia that is older than 22.4±0.05 Myr1,2 and the specimen is, by more than 85Myr, the oldest known monotreme. As the oldest monotreme, it will necessitate a radical revision of present understanding about dental homology in the middle Miocene Obdurodon insignis, the only fossil monotreme previously known to have had teeth3. The structure of S. galmani supports one current view4 that monotremes, one of three groups of living mammals (the other two being marsupials and placentals), are phylogenetically close to the other groups of living mammals.

Early Cretaceous mammals from northern Texas

<b>Aims:</b> To examine derived indices of β cell function, peripheral insulin sensitivity, and the pancreatic response to intravenous glucose loading in children with a previous history of transient neonatal diabetes currently in remission, repeated after a period of two or more years. <b>Methods:</b> The standard intravenous glucose tolerance test (IVGTT) was used to measure the first phase insulin response (FPIR) cumulatively at one and three minutes. In addition, fasting insulin and glucose values were used to estimate insulinogenic indices (β cell function) and QUICKI (insulin sensitivity). <b>Patients:</b> Six patients with known previous transient neonatal diabetes currently in remission with no exogenous insulin requirement were tested. Control data from 15 children of a similar age were available for derived fasting indices of β cell functional capacity and insulin sensitivity. <b>Results:</b> One child had a subnormal insulin secretory response to intravenous glucose that remained abnormal two and four years later. The other children had relatively normal or entirely normal responses over two years. Measures of β cell function and insulin sensitivity in the fasting state showed comparable results to those obtained from normal controls. <b>Conclusions:</b> Most children with transient neonatal diabetes in remission have no evidence of β cell dysfunction or insulin resistance in the fasting state, although they might have been expected to show subtle defects given the tendency to relapse in adolescence. Measures of insulin response to intravenous glucose loading are often normal but suggest future recurrence if profoundly abnormal.

Discovery of Early Cretaceous Mammals and Frogs in Texas

Discovery of Early Cretaceous Mammals and Frogs in Texas

Discovery of early cretaceous mammals and frogs in Texas.

Discovery of early cretaceous mammals and frogs in Texas.