abbyhoward

Ancient Mammals of Australia

Added 2018-12-31 18:37:02 +0000 UTC

Cenozoic Australia is always very interesting to learn about. It was a semi-isolated continent, which means the life there was able to evolve in very different directions than the life on other continents, resulting in some very unique critters. It's the only continent where marsupials, rather than placental mammals, became the dominant group, and the only continent that still has monotremes. So I've highlighted a few of my faves!

Also, the evolution of milk is fascinating and a little gross-- milk started out as a slightly more nutrient-rich sweat, and it leaked from glands in the skin, like sweat does. Over time, these glands became concentrated in certain areas, and the nutrient sweat they produced became more and more concentrated, and eventually these little clusters became nipples and what were once sweat glands had been changed into milk-producing mammary glands.

Monotremes have spaced-out milk glands, which is why they don't have nipples. Amazing!!

I'll have a new post for you next month all about the reptiles and birds of Cenozoic Australia, but until then, have an incredible New Year <3