The spears' discoverer, however, German archaeologist Hartmut Thieme, reports in the Feb. 26 issue of the journal Nature that the artifacts are clearly 400,000 years old, based on the well-known age of the 10-meter-deep geological layer in which they were uncovered. The spears were unearthed along with notched wooden implements that presumably held stone blades, sundry stone tools, the remains of a fire and thousands of horse bones (some showing evidence of butchery).
At that time, Thieme says, the site was on the shore of a flat lake in a cool, open landscape of meadows and steppes.
[Thieme, of] the Institute for Historic Site Preservation in Hanover, who has been excavating the mine area for more than 15 years, said he is "very sure" that the spears, which average 2 meters in length and nearly 5 cm in maximum diameter, were designed to be thrown at large animals.
The center of gravity or balance point of each spear is almost exactly one third of the way from the point. Modern javelins are built on the same aerodynamic pattern with the same balance, Thieme said, and the well-preserved spruce wood bears unmistakable evidence of meticulous working with stone tools.
British archaeologist Robin Dennell argues in an accompanying essay in Nature that the objects are "unquestionably" throwing spears fashioned with patient skill, and that "to regard them as snow probes or digging sticks is like claiming that power drills are paperweights."
Researchers have found two other apparent cases of early artisans: a 125,000-year-old spear dug up near Lehringen, Germany, in 1948; and a 500,000-year-old rhino bone found in England that has a circular hole that could have been produced by a flying spear.
Thieme's claim is strong because the coal-mine area has been extensively studied and is known to contain evidence of several interglacials, as the period between ice ages are called. If Thieme's artifacts are accepted as 400,000-year-old throwing spears, it will substantially revise the reputation of Europe's primordial humanlike (hominid) immigrants. Earlier this century, experts tended to believe that our ancestors during that period, somewhere in the transition between the coarse but cunning Homo erectus and the more slender, brainy and dexterous modern Homo sapiens, were noble hunters who roamed in search of mastodon or other big mammals.
In the 60s, says Kathy Schick of the CRAFT center at Indiana University, skeptics began to emphasize the embarrassing absence of definitive evidence that large animals actually had been killed by early hominids.
Over the next 30 years, scientists gradually came to a tentative consensus that the predecessors of modern humans were probably opportunistic scavengers who usually ate vegetable foods and hunted small animals. If they got meat from large prey, it was likely taken from carcasses of animals killed by other predators and then skinned and dismembered with stone tools.
The new German claim defies those assumptions. "It really argues that to live in these [cold northern European] places at all, people really had to be hunters," Brooks says. "They couldn't rely on just whatever happened to die. They couldn't have survived that way because throughout too much of the year there would have been no alternative food sources to meat."
In addition, Toth and Schick noted, conclusive proof of deliberate big-game hunting would have other important implications for the hominids' society. Scavenging can be done more or less at random, but systematic hunts require "another threshold of social organization.
"You don't have to be a rocket scientist," Toth says, "but it probably does require more group activity and coordination of members of groups."