Monash University researcher explores evolution of the world's largest mammals over the past 100 million years

Researchers have demonstrated that the extinction of dinosaurs 65 million years ago paved the way for mammals to get bigger - about a thousand times bigger than they had been.

The study, released today in the prestigious journal Science, is the first to quantitatively explore the patterns of body size of mammals after the demise of the dinosaurs.

The research, funded by a National Science Foundation Research Coordination Network grant, was led by scientists at the University of New Mexico and brought together an international team of palaeontologists, evolutionary biologists, and macroecologists from universities around the world.

To document what happened to mammals after the extinction of dinosaurs, researchers collected data on the maximum size for major groups of land mammals on each continent, including Perissodactyla, odd-toed ungulates such as horses and rhinos; Proboscidea, which includes elephants, mammoth and mastodon Xenarthra; the anteaters, tree sloths, and armadillos; as well as a number of other extinct groups. The researchers spent three years compiling the large database.

Dr Alistair Evans, a co-author on the paper and an Australian Research Fellow at Monash University, said the database is unique.

"The database allows us for the first time to compare maximum size of mammals on different continents since the extinction of the dinosaurs."