Dinos away, mammals play
The Kayentatherium, a Mesozoic-era mammal, is pictured in this illustration with a pair of Dilophosaurus in the background and the prehistoric turtle Kayentachelys in the foreground. A new study suggests that mammals, which were largely noctur-nal during the age of dino-saurs, became more active in daytime shortly after the dinosaurs went extinct.
A supervolcano's underground ocean of magma is not red-hot molten lava. It is at a low enough temperature to be solid. Analysis of volcanic leftovers from an ancient California supereruption found that the magma had melted just before the eruption. The study, published in Proceedings of the National Academy of Sciences, may help scientists forecast when such volcanoes pose a threat.
A woman smells a tree during a "smellwalk" in the Williamsburg neighbourhood of New York. Your sense of smell may fluctuate over the course of 24 hours, in tune with your circadian clock, with your nose best able to do its job during the hours before you go to sleep, according to a recent study in Chemi-cal Senses. The work is part of a larger push to explore whether adolescents' senses of taste and smell influence obesity.