Research from the Australian Museum, Museums Victoria, Monash University and the Smithsonian Institution have put forward an interesting argument: that Australia is the ‘wellspring of modern mammal evolution’.
Originally when I read this line I let out a resounding ‘yeah, sure’, remembering that our humble nation is home to some of the most f*cked up-looking creatures to grace this planet.
But it’s actually a lot deeper than that, involving the evolution of creatures from all around the world stemming from the Gondwawan supercontinent (made up of countries like South America, Africa, Arabia, Madagascar, India, Australia, and Antarctica) some 176 million years ago, before migrating to Asia 126 million years ago.
“Our research shows that therian fossils from the Cretaceous of Australia, dating from around 126 to 110 million years ago, share characteristics with… … Jurassic Southern Hemisphere forms and the modern Northern Hemisphere Theria,” honorary associate of the Australian Museum Professor Flannery said.
“This new research has completely revised and turned on its head our understanding of early mammal evolution. It’s the most important piece of palaeontological research, from a global perspective that I’ve ever published, but it may take some time to find full acceptance among Northern Hemisphere researchers.”
This research indicates that early versions of mammals existed on the early Gondwana supercontinent, in particular from Australia.
Teeth were an important part of the analysis process and gave useful indicators on the travel and evolution of creatures, helping to paint a broader picture, and once mammals arrived in Asia, they diversified to fit their new environments.
“Dating mammal lineages depends on both genetic analysis and the fossil record. We also date the rock around the fossil. With our latest research, we have succeeded in filling the gaps to draw a detailed portrait of the early evolutionary history of Theria.” Palaeontologist Doctor Tom Rich added.
“These astonishing series of discoveries have completely changed our long-held theory of mammal evolution. Indeed, it turns our ideas of mammal evolution on its head.”
Research is ongoing, but it’s pretty jaw-dropping stuff. As the team outlines in the announcement, Australia is home to the only two non-therian mammals alive today, the echidna and the platypus, which themselves are indicators of the interesting evolutionary environment that the country has. Additionally, Australia has a higher mammal diversity than any other continent, with 350 native mammals, roughly half of which being marsupials.
Australia being a ‘wellspring of modern mammal evolution’ seems to have influenced the evolution of mammals across the world. We love to see it.
You can read about the research on Scimex or in Alcheringa.