CAUSES OF NORTHERN GIANTS' EXTINCTION
Author: ALEXEI TIKHONOV, YURI BURLAKOV
by Alexei TIKHONOV, Dr. Sc. (Biol.), Deputy Director of the RAS Zoological Institute (St. Petersburg), Yuri BURLAKOV, Vice-President of the Russian Association of Polar Explorers (Moscow)
There are many scientific theories of mammoths' extinction. Their authors are unanimous in the opinion of the time of these animals' extinction (mammoths are sometimes described as northern elephants), i.e., the period that lasted from the end of the last Ice Age (12,000 - 10,000 years ago) to the mid-Holocene Period (6,000 - 4,000 years ago). Then the austere climatic conditions gave place to those close to present conditions. That is why unraveling of the mystery is closely bound up with our knowledge and interpretation of the processes that contributed to global climate change in the past.
Steppe or trogontherian mammoths (M. Trogontherii) that inhabited Eurasia and Northern America in the Early Pleistocene Period (350,000 - 450,000 years ago) were the most ancient members of the Mammuthus genus (it includes 4 or 6 species, according to the estimates of various systematizing paleontologists). They were very large-size animals: their skeleton in the most prominent spot was up to 450 cm high as against 320 - 265 cm for the woolly mammoth (M. primigenius), to say nothing of the small mammoth species of the Californian Channel Islands whose height did not exceed 180 - 200 cm. Climate in the period was moderate-warm in middle latitudes and moderate - in northern latitudes.
Siberia's extreme northeast was overgrown with deciduous forests interspersed with vast meadow and steppe tundra, and giant mammoths with their massive slightly curving tusks up to 4 m large and weighing up to 130 kg grazed there. However, they were poorly adapted to cold, and that is why M. primigenius replaced them in Eurasia and M. columbi - in Northern America. At the close of Pleistocene the former joined their M. columbi counterparts, having crossed ...