From Nature:
The discovery of additional bones in an Indonesian cave support a stunning claim made last year that a new species of a very small hominid existed at the same time as modern humans. When Michael Morwood and Peter Brown of the University of New England in Armidale, New South Wales, and their team announced last October that they had found the partial skeleton of a meter-tall human in the cave of Liang Bua on the island of Flores, they raised a few eyebrows. The evidence, including stone tools, signs of fire and the bones of a dwarfed elephantlike beast, dated to about 18,000 years ago and prompted the scientists to assign the human remains to a new species, Homo floresiensis. Rebuttals ensued.
When the team published their first report on H. floresiensis, they proposed that it was a dwarfed descendant of Homo erectus, which may have arrived on the island hundreds of thousands of years earlier and evolved into a smaller being thanks to the lack of predators and limited resources.
More here.