Mammals can produce their own body heat and control their body temperatures.This process is known as endothermy or warm-bloodedness.Scientists believe that it may be the reason why mammals likely rule almost every ecosystem.Warm-blooded mammals are more active than cold-blooded animals.They can live in different environments, from the frozen arctic to the boiling desert.And they reproduce faster.The soft tissues that would give information about warm- or cold-bloodedness are rarely preserved in fossils.So, paleontologists, or experts in the study of fossils, do not know exactly when mammals developed and changed into warm-blooded creatures.A group of scientists tried to answer that question in a study recently published in Nature.Ricardo Araújo is a paleontologist at the University of Lisbon.Araújo and a group of researchers proposed that the shape and size of the inner ear structures called canals could be used to study body temperature.The movement of fluid through the ear canals helps the body to preserve balance and movement.
