The shapes of the ear canals of mammal ancestors reveal when warm-bloodedness evolved. The study published in Nature demonstrates that mammal ancestors became warm-blooded later than previously thought – nearly 20 million years later-, and that the acquisition of endothermy seems to have occurred very quickly in geological terms, in less than a million years. The international team of scientists, led by London’s Natural History Museum, the University of Lisbon’s Instituto Superior Técnico, the Field Museum in Chicago, and including the University of Witwatersrand, used the ESRF bright X-rays to scan delicate and dense fossils.
Read more on the ESRF website
Image: Comparison of bony labyrinth shape in two examples of warm-blooded (left) and cold-blooded (right) prehistoric mammal ancestors. © Romain David and Ricardo Araújo.