PLUTO - Once ninth planet now first plutoid. Scientists say there might be scores of plutoids yet to be discovered.

The International Astronomical Union (IAU) says the dwarf planrt Pluto is no longer a dwarf, but a plutoid, and there are others. The category applies to all dwarf planets beyond the orbit of Neptune, including Eris discovered in 2005.

A region around the orbit of Pluto called the Kuiper Belt may contain more.

The IAU says there may be fifty or more plutoids orbiting within the belt. There are theories the Kuiper Belt is debris which never coalesced into a full planet.