Origin of birds

o Dinosaurs developed characteristics enabling them to fly earlier than previously believed. o New research helps scientists better understand bird origin Characteristics that allowed dinosaurs to take to the skies arose much earlier than scientists previously believed, new research has revealed - giving fresh insight into the origin of birds. Dr Gavin Thomas, from the University of Sheffield's Department of Animal and Plant Sciences, and colleagues from the University of Bristol investigated the rates of evolution of the two key characteristics that preceded flight in dinosaurs - body size and forelimb length. In order to fly, hulking meat-eating dinosaurs had to shrink in size and grow much longer arms to support their feathered wings. Scientists have now discovered this happened earlier than previously believed and dozens of little dinosaurs were actually lightweight with wings and were either gliders or parachutists, spreading their feathered wings, but not flapping them. "This was at least 20 million years before the first bird, the famous Archaeopteryx, and it shows that flight in birds arose through several evolutionary steps," said Mark Puttick of Bristol's School of Earth Sciences. The study applied new numerical methods that calculate the rate of evolution of different characteristics across a whole evolutionary tree, and identify where bursts of fast evolution occurred.