Place a male and a female Veloceraptor, the desert ones, and wait until they mate and the female is pregnant. She will start building a nest. You will be informed when the nest is being built in the top information bar. Click on the female Veloceraptor. Click on its picture to track it. When it is done building its nest it will lay an egg. Just when it lays the egg, somewhere in its exhibit a baby kangaroo will slowly rise up from the ground and eventually disappear. This can happen even if you do not have any kangaroos. However this glitch does not always work; just every once in a while when the Velociraptor lays eggs.