In a new study, paleontologists from the United Kingdom and Sweden reviewed the fossil evidence of locomotion of kangaroos and their relatives (wallabies, tree-kangaroos, rat-kangaroos, etc.) over the last 25 million years. Their results indicate that the higher-speed endurance-hopping typical of modern large-bodied kangaroos was probably rare or absent in all but a few large-bodied lineages, including the direct ancestors of modern large kangaroos...
