In the rainforests and mountains of Central and South America live more than 60 species of treefrogs of the genus Gastrotheca that have an unusual mode of reproduction. Their eggs develop not in water but on the mother's back, inside a special pouch. Certain features of this unique mode of reproduction recall pregnancy in mammals; others are unique. In many cases the young emerge as fully formed froglets, in others tadpoles complete these development in water.
