The "extremely rare" fossilised skull of a steppe mammoth has been unearthed in southern France. The discovery in the Auvergne region could shed much needed light on the evolution of these mighty beasts. Many isolated teeth of the steppe mammoth have been found, but only a handful of skeletons exist; in these surviving specimens, the skull is rarely intact. Palaeontologists Frederic Lacombat and Dick Mol describe this skull specimen as being well preserved.
It belongs to a male steppe mammoth (Mammuthus trogontherii) that stood about 3.7m (12ft) tall and lived about 400,000 years ago, during Middle Pleistocene times. The researches estimate that the animal was about 35 years of age when it died. The steppe mammoth is of vital importance for understanding mammoth evolution. It represents the transitional phase between an ancient species known as the southern mammoth and the more recent woolly mammoth.
Comparatively little is known about this intermediate stage of their evolution. "This specimen is of extreme importance because we don't know that much about the Middle Pleistocene," Mr Mol, from the Museum of Natural History in Rotterdam, the Netherlands, told BBC News. He added: "We cannot keep saying that we have the [southern mammoth] at the beginning of the Pleistocene, then we have something which we are not sure about, and finally we have the woolly mammoth [at the end of the Pleistocene]. "We need to find what I call the 'missing link' in mammoth evolution."
The southern mammoth appears to have lived in a savannah environment and was probably a "browser", feeding on trees and shrubs. However, the molar teeth of the steppe mammoth and the woolly mammoth show that these animals were adapted to grazing. This is thought to represent an adaptation to climate change; as conditions got colder and drier over the Pleistocene period, the savannah disappeared making way for grassy steppe. The mammoth had to adapt their diets accordingly.
"If they have a complete skull then that would be very valuable," Dr Adrian Lister, a mammoth expert from London's Natural History Museum and University College London, told BBC News.
Evolutionary debate
According to a theory developed by Dr Lister and his colleagues, the southern mammoth was once widespread in Eurasia, but evolved into a cold-adapted form - the steppe mammoth - in eastern Asia, where the climate has been chilly for the last two million years. However, when Ice Age conditions took hold across the northern hemisphere the steppe mammoth spread outwards, replacing its predecessor in Europe and Asia. A similar process may have later led to the emergence of the woolly mammoth. According to Dr Lister, it evolved from the steppe mammoth in north-east Siberia, then expanded its range during an Ice Age, eventually displacing its forerunner the steppe mammoth.
However, Dick Mol takes a different view. He thinks evolutionary changes in the mammoth lineage take place too quickly under this model. Instead, he favours a model in which Europe is the centre for mammoth evolution. Two molar teeth belonging to the newly discovered specimen were found in 1986, during the construction of a water pipeline. Frederic Lacombat was able to trace the site of this discovery, and subsequent excavations revealed the skull from which they had come. The team plans to lift the skull out of the ground and transport it on a truck to the Crozatier Museum in nearby Le Puy-en-Velay.
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Article first published on the BBC News website, 2nd September 2008, and written by Paul Rincon, their Science reporter, BBC News. ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it )
