'Dwarf' Mammoths Outlived Last Ice Age
Bower, Bruce, Science News
Woolly mammoths, those icons of the ice age that most paleontologists assume died out around 9,500 years ago, survived in miniature form - or what passed for miniature among mammoths - until about 4,000 years ago on an Arctic Ocean island, according to new findings.
Mammoth teeth found in 1991 on Wrangel Island, located 120 miles off the coast of northeast Siberia, range from approximately 7,000 to 4,000 years old, report Andrei V. Sher and Vadim E. Garutt, paleontologists at the Russian Academy of Sciences in Moscow. The relatively small teeth suggest that Wrangel "dwarf mammoths" reached at most 70 percent of the size of their Siberian kin, the researchers say.
"[This is] one of the most extraordinary fossil finds of recent times," writes Adrian M. Lister, a biologist at University College in London, England, in a comment accompanying the new report in the March 25 NATURE.
He estimates that the Wrangel animals stood 6 feet high and weighed 2 tons, compared with 10 1/2 feet and 6 tons for typical European mammoths.
The Wrangel finds may reignite debate over the reasons for the widespread mass extinctions of large mammals between 12,000 and 10,000 years ago, Lister notes. Some researchers contend that the waning ice age produced abrupt environmental changes that doomed many creatures. Others argue that human hunters, at least in North America, rapidly killed off many large-bodied species (SN: 10/31/87, p.284).
"This is a wonderful discovery, however we end up interpreting its significance regarding mass extinctions," remarks Paul S. Martin, an ecologist at the University of Arizona in Tucson, who favors the latter theory,
Sher and Garutt studied 29 adult mammoth cheek teeth found by Sergei L. Vartanyan, a paleontologist at Wrangel Island State Reserve. …