Were dinosaurs warm- or cold-blooded? First method for directly measuring body temperatures of extinct vertebrates

ScienceDaily (2010-05-25) -- Questions about when, why, and how vertebrates stopped relying on external factors to regulate their body temperatures and began heating themselves internally have long intrigued scientists. Now, a team of researchers has taken a critical step toward providing some answers. They have developed the first method for the direct measurement of the body temperatures of large extinct vertebrates -- through the analysis of rare isotopes in the animals' bones, teeth, and eggshells.