The current Science has meetings reports from the Indo-Pacific Prehistory Association Congress, including this article by Richard Stone about excavations from Sangiran:
At the meeting, archaeologist Harry Widianto of the National Research Centre of Archaeology in Yogyakarta, Indonesia, wowed colleagues with slides showing stone tools found in sediments that he says were laid down 1.2 million years ago and could be as old as 1.6 million years. The find, at a famous hominid site called Sangiran in the Solo Basin of Central Java, "opens up a whole new window into the lifeways of Java Man," says paleoanthropologist Russell L. Ciochon of the University of Iowa in Iowa City.
This report is the latest in a series of finds from the site, which have been increasing in date:
Over 2 months, they unearthed 220 flakes--several centimeters long, primarily made of chalcedony, and ranging in color from beige to blood red--in a 3-by-3-meter section of sand deposited by an ancient river.
The find, not yet published, could be even more spectacular than Widianto realizes, says Ciochon. His team, which also works at Sangiran, has used ultraprecise argon-argon radiometric methods to date the volcanic strata overlying the levels excavated by Widianto to 1.58 million to 1.51 million years ago--making the flakes at least 1.6 million years old. If the flakes were undisturbed, Ciochon says, they would represent "some of the earliest evidence of the human manufacture of stone artifacts outside of Africa." Their antiquity would match that of the oldest flakes found in China, at Majuangou, dated to 1.66 million years ago and also made of chert.
The article includes a picture of some of the tools, which are small flakes on a fine-textured material.
The Sangiran flakes "are fundamentally different"--smaller--than the stone choppers made by H. erectus in Africa, says Ciochon. The evidence, he argues, suggests that Java Man had to range far for small deposits of good flint or chert and so created small, finely worked tools in contrast to the larger tools found in Africa.
There certainly is a contrast in the absence of large core tools, but it would take a close study to show that the flakes are different. But if there was a conscious limit to the selection of good raw materials, that might be significant also.