Dwarf elephants? Giant rats? Strange island creatures at high risk

FILE PHOTO: A mounted skeleton of an extinct Sicilian dwarf elephant, the size of a Shetland pony, is seen at Museo Geologico “G. G. Gemmellaro” in Palermo, Sicily, Italy in this undated handout photo. Dwarf elephants that lived in Sicily and Cyprus were examples of the "island effect," a rule in evolutionary biology describing how large-bodied species tend to downsize on islands while small-bodied species upsize. Roberto Rozzi/Handout via REUTERS

WASHINGTON (Reuters) - A dwarf elephant the size of a Shetland pony once roamed the Mediterranean island of Cyprus. In the West Indies, a giant rat-like rodent tipped the scales at more than 400 pounds (180 kg), rivaling an American black bear.

They were examples of the "island effect," a rule in evolutionary biology describing how large-bodied species tend to downsize on islands while small-bodied species upsize. These island dwarfs and giants - a menagerie also including pint-sized hippos, buffaloes and wolves - long have faced an elevated extinction risk that, according to a new study, is intensifying, imperiling some of Earth's most unique creatures.