Australian placental cats

by Greg Mayer

Australia is a zoogeographer’s dream world—it’s the most spectacularly distinctive place on Earth, and we know why. Around 250 million years ago, most of the world’s continental plates amalgamated into a single super-continent—Pangaea. During the Mesozoic (the “Age of Reptiles”), Pangaea began breaking up, with many of today’s southern continents (South America, Africa, Antarctica, Australia, and India) pulling away to form the somewhat smaller super-continent of Gondwanaland.

The continental breakup continued, with the various parts of Gondwana separating from one another (hence the traditional rallying cry of irredentist geologists, “Reunite Gondwanaland!”). Africa, India, and, most recently, South America eventually bumped into the northern continental masses, making for interesting geology, and—of the greatest importance for zoogeography—allowing large land animals to move between the major land masses. Such animals are not, in general, susceptible to “occasional means of transport”, as Darwin called them, that allow birds, bats, and smaller animals…