After thoroughly studying the site for several years, paleontologists in Australia revealed yesterday that they have found a large cave in the Outback filled with a rare find.  Fossilized remains, many of them complete skeletons of 15-million-year old marsupials known as Nimbadons, were recovered.  Nimbadons were a sheep-sized animal with many features similar to wombats, such as large claws most likely used to climb trees.  The highlight of the fossil find was that quite a few of them showed the skeletons of babies, obviously originally carried in a pouch, in various stages of development.  The skeletal remains showed that the babies' skulls strengthened quickly in the front, hinting at the early development of muscles used in suckling milk from their mothers, just like modern-day kangaroos, and revealing that even millions of years ago, Australian animals lived as they do today.