New theory on why the woolly mammoth became extinct

Bone disease and a lack of calcium could have led to the extinction of the woolly mammoth, according to new analysis by a Siberian palaeontologist.

Sergey Leshchinsky has spent more than a decade examining 23,500 bones and teeth belonging to the hairy beast, and found almost every one had traces of osteoporosis.

He has concluded that climate change and associated geological processes affected the chemical composition of soil and water in the mammoths' habitat, and led to them suffering from chronic mineral shortages.

That in turn, he said, resulted in them often breaking their limbs and spines, left them open to predators and caused them problems simply surviving.

'The articular surfaces of the limb bones in some specimens are not just damaged, they are mutilated with disease,' said Dr Leshchinsky, the head of the laboratory of the Mesozoic and Cenozoic continental eco-systems at Tomsk State University.

'As for osteoporosis, in some collections that we examined almost 100 per cent of bones had signs of it. Obviously, this led to a high traumatism among animals, such as sprains and fractures because of the smallest loads. Mammoths with damaged limbs or spines could not find food in sufficient quantities and lost the ability to follow the herd.

'Those who lagged behind the herd quickly became the prey of predators.'

It has been established that the mass death of mammoths began about 20,000 to 24,000 years ago. The process continued for a long time and had a pronounced second wave of extinctions that occurred 13,000 to 15,000 years ago.

The last major wave of deaths occurred about 9,000 to 12,000 years ago although there is evidence they survived in smaller groups near Alaska and at Wrangel Island, in the Russian Arctic, as recent as 3,700 years ago.

Dr Leshchinsky conducted large-scale research on mammoth bones between 2003 and 2013, before writing about some of his conclusions in the September 2014 issue of the Archaeological and Anthropological Sciences journal.

His focus was on the sites in western Siberia and Europe with lots of remains dating between 10,000 and 30,000 years old. 

He examined bones from the following locations: Shestakovo-Kochegur (Kemerovo region), Volchya Griva (Novosibirsk region), Lugovskoye (Khanty-Mansi Autonomous District), Gari (Sverdlovsk region, Urals), Berelyokh (Yakutia), Krasnoyarskaya Kurya (Krasnoyarsk region), Krakow Spadzista Street (Poland), Predmosti, Dolni Vestonice , Milovice (Czech Republic) and others. 

Dr Leshchinsky found out that 'mammoths experienced powerful geochemical stress'. He said: 'The most typical signs were osteoporosis, osteofibrosis, osteomalacia, osteolysis, cartilage atrophy and fractures resulting in the formation of false joints, ulcers and friction grooves.

'Here is a specific example: there was a jaw of a young mammoth discovered during the expedition to Teguldetskiy district (Tomsk region). Its age was not more than 10 years. Without a doubt, the animal was sick, as indicated by improper stitching teeth and their different sizes.'

The palaeontologist said that in his opinion the cause of the deaths was a metabolic disorder caused by mineral starvation, and provoked by the drastic environmental changes. 

He concluded that 'the transformation of the geochemical landscapes made the large part of Northern Eurasia extremely unfavourable for the existence of megafauna and mammoths in particular.'

It is thought that mammoths that lacked calcium tried to make up for their mineral shortfall by eating clay on the waterfronts or in mud baths. Sadly, it was not enough to save them.