文摘
The Muirkirk Mammoth, found in 1895 2.4?km northeast of the village of Muirkirk in southern Ontario, is the most complete woolly mammoth (Mammuthus primigenius) skeleton known from Canada. Approximate tusk measurements and extreme wear on the sixth molars indicate it is best referred to an old male. Its geological age was controversial because the first two Holocene bone collagen radiocarbon dates were derived evidently from contaminated samples. Three new radiocarbon dates on carefully selected bone and ivory are close, averaging 12,190?BP, and indicate that this mammoth died before the close of the Wisconsinan glaciation and near the time of extinction of woolly mammoths in this part of North America. Its assignment to regional pollen subzone 1b suggests that, like the Rostock Mammoth of similar age from southern Ontario, it lived in a tundra woodland environment. The Highgate Mastodon (Mammut americanum) and giant beaver (Castoroides ohioensis) found 4?km away and also assigned to pollen subzone 1b suggests that some spruce wetlands characterised the tundra woodland environment, and that perhaps woolly mammoths and American mastodons lived almost side by side in southern Ontario about12,000 radiocarbon years or 14,000 calendar years ago. The Muirkirk Mammoth is discussed in relation to the dispersal history of woolly mammoths.
