As much as they look like teddy bears, they are not bear cousins. These marsupials are more closely related to wombats. Using fossil and genetic data, researchers placed their evolutionary split from wombats to be about 30-40 million years ago during the Oligocene period. Both of these animals belong to the suborder Vombatiformes. Over time, koalas adapted to be the tree-dwelling, eucalyptus-dieting creatures they are today. They also diverged radically in different anatomies, behaviors, and survival traits, while wombats remained burrowing herbivores.