Discoveries from a 140-year-old Tassie tiger brain sample that endured two world wars and reached our laboratory

Researchers often consider the timing and publication of their findings, but many research projects remain unpublished for decades or even centuries. This is the case with a detailed atlas of the Tasmanian tiger or thylacine brain, which was processed over 140 years ago and is now being published in the journal PNAS.

Thylacines were carnivorous marsupials similar in appearance to wolves and dogs. They once roamed Australia and New Guinea but became confined to Tasmania around 3,000 years ago. The arrival of European colonists and the introduction of farming, diseases, and hunting led to their extinction. The last known thylacine died in 1936, and September 7 is now National Threatened Species Day in Australia to raise awareness about conservation.

Studying the brains of thylacines has been challenging due to a lack of available material for microscopic studies. However, in this newly published study, researchers uploaded high-resolution images of brain sections from a thylacine that died in the Berlin Zoo in 1880. These images were made available to the public for further study.

Although limited information about the specimen was available, researchers preserved the samples because of their biological significance. The samples were initially held by German scientists and later transferred to the Max Planck Institute for Brain Research before being returned to Australia in 1973.

After analyzing the samples, researchers found that the thylacine brain closely resembles that of other carnivorous marsupials, such as dunnarts, quolls, and Tasmanian devils, rather than wolves or other canids. The cerebral cortex, responsible for planning actions and sensing the environment, was larger in thylacines compared to other dasyurids. Brain regions associated with processing smells suggest that scavenging and hunting behaviors were important for this species.

By making this material openly available, researchers hope to provide a clearer understanding of the thylacine species. Ongoing research using dunnarts is also contributing to insights about the development and evolution of mammalian brains.