Australian Museum Study Challenges Mammalian Origins Theory

A new study led by Prof Tim Flannery and Prof Kris Helgen at the Australian Museum Research Institute challenges the long-held belief that placental and marsupial mammals originated in the northern hemisphere. Published in the journal Alcheringa, the research examines fossilized tribosphenic molars from Jurassic period sites in Madagascar, South America, and India, which predate northern hemisphere specimens by 50 million years. The findings suggest that Theria mammals may have first evolved in Gondwana, migrated from Australia to Asia via volcanic arcs, and later spread to Europe and North America. The study provides evidence for Australia's role in mammalian evolution, though early southern hemisphere lineages did not survive, with all living descendants tracing back to species that migrated from Australia to Asia.