Found in Wonderkrater in the Limpopo Province, north of Pretoria in South Africa

A huge asteroid may have hit the Earth 12,800 years ago causing global climate change and extinction, according to new evidence found in South Africa.

Scientists analysed ancient soil at a site called Wonderkrater and found high levels of platinum - which they say supports the The Younger Dryas Impact Hypothesis that a disintegrating meteor hit Earth and caused a mini ice age.

The resulting ice age is believed by many scientists to have wiped out dozens of mammals species including the Mammoth and giant wildebeest and decimated the human population.

Scientists believe 'platinum spikes' found in ancient soil samples across the world are evidence of the meteor fragments that crashed into Earth.

Meteorites are rich in platinum and the Wonderkrater site in the Limpopo Province, north of Pretoria in South Africa adds to almost 30 other platinum spikes found worldwide, mostly in the northern hemisphere.

This map shows the locations of platinum spikes which have been observed around the world, suggesting a meteorite may have smashed into Earth and scattered debris everywhere

WHAT IS THE YOUNGER DRYAS IMPACT HYPOTHESIS? The Younger Dryas impact hypothesis proposes that fragments of a disintegrating comet struck the Earth around 12,800 years ago. These fragments bombarded North and South America, Europe and western Asia. This generated a thin layer of detritus covering around 19.3 million square miles (50 million square kilometres). This layer contained concentrations of platinum, meltglass and nano-diamonds from the impactors. Experts argue that this episode saw large-scale biomass burning, an impact-induced winter, longer-time climatic shifts and the extinction of late Pleistocene megafauna. Advertisement

Until now, proof that meteoroids had impacted during that period and potentially led to a mini-ice age had only been documented across the northern hemisphere.

A total of 28 areas with high levels of platinum had been found.

The findings from the researchers at the University of the Witwatersrand in Johannesburg, South Africa partially support the theory that a meteorite crashed into earth with global consequences – along with another meteorite site discovered in Chile.

An episode of rapid cooling named the The Younger Dryas is a well documented period believed to have contributed to the extinction of many species of large animals around 12,800 years ago.

Theories previously pointed to this post-ice age cooling as a result of changes in oceanic circulation systems.

Another theory was presented by American scientists in 2007 – that the cooling was triggered by the dust fallout of an asteroid impact.

Dust circulating in the atmosphere after an impact could have reduced the amount of sunlight reaching the earth, affecting plant growth and temperatures on earth.

Now Francis Thackeray of the Evolutionary Studies Institute at the University of the Witwatersrand in South Africa believes a platinum spike found in South Africa proves the extinction of many large animals globally could have been caused by one or multiple meteoroid impacts.

Researchers have discovered their first evidence in the southern hemisphere that a mini ice age almost 13,000 years ago may have been caused by clouds of dust thrown up by an asteroid impact (stock image)

Dr Thackeray who was working with researcher Philip Pieterse from the University of Johannesburg and Professor Louis Scott of the University of the Free State, said: 'Our finding at least partially supports the highly controversial Younger Dryas Impact Hypothesis (YDIH).

'We seriously need to explore the view that an asteroid impact somewhere on earth may have caused climate change on a global scale.

'And [it may have] contributed to some extent to the process of extinctions of large animals at the end of the Pleistocene, after the last ice age.'

Many mammals became extinct in North America, South America and Europe at the time of the Younger Dryas.

In South Africa a few extraordinary large animal species became extinct around that period including the giant African buffalo, a large zebra, and a very big wildebeest each weighing around 1,100lbs (500kg) more than its modern counterpart.

Human populations may also have been indirectly affected at the time in question.

Thackeray argues that a dramatic halt in the development of the use of stone tools by the Clovis people in North America and the Robberg stone artefacts used by populations in South Africa around that period could indicate that an asteroid may have caused global consequences.

Dr Thackery said: 'Without necessarily arguing for a single causal factor on a global scale, we cautiously hint at the possibility that these technological changes, in North America and on the African subcontinent at about the same time, might have been associated indirectly with an asteroid impact with major global consequences.'

WHEN WERE EARTH'S 'BIG FIVE' EXTINCTION EVENTS? Traditionally, scientists have referred to the 'Big Five' mass extinctions, including perhaps the most famous mass extinction triggered by a meteorite impact that brought about the end of the dinosaurs 66 million years ago. But the other major mass extinctions were caused by phenomena originating entirely on Earth, and while they are less well known, we may learn something from exploring them that could shed light on our current environmental crises. The Late Ordovician : This ancient crisis around 445m years ago saw two major waves of extinction, both caused by climate change associated with the advance and retreat of ice sheets in the southern hemisphere. This makes it the only major extinction to be linked to global cooling. The Late Devonian : This period is now regarded as a number of 'pulses' of extinction spread over 20m years, beginning 380m years ago. This extinction has been linked to major climate change, possibly caused by an eruption of the volcanic Viluy Traps area in modern-day Siberia. A major eruption might have caused rapid fluctations in sea levels and reduced oxygen levels in the oceans. The Middle Permian : Scientists have recently discovered another event 262m years ago that rivals the 'Big Five' in size. This event coincided with the Emeishan eruption in what's now China, and is known to have caused simultaneous extinctions in the tropics and higher latitudes. The Late Permian : The Late Permian mass extinction around 252m years ago dwarfs all the other events, with about 96% of species becoming extinct. The extinction was triggered by a vast eruption of the Siberian Traps, a gigantic and prolonged volcanic event that covered much of modern day Siberia, which led to a cascade of environmental effects. The Late Triassic : The Late Triassic event, 201m years ago, shares a number of similarities with the Late Permian event. It was caused by another large-scale eruption, this time of the Central Atlantic Magmatic Province, which heralded the splitting of the supercontinent Pangaea and the initial opening of what would later become the Atlantic Ocean. Advertisement

A meteor glowing as it enters the earth's atmosphere (stock image)

He added: 'We cannot be certain, but a cosmic impact could have affected humans as a result of local changes in environment and the availability of food resources.'

At Wonderkrater, the team has also uncovered evidence from pollen to show that about 12,800 years ago there was temporary cooling.

This linked up with the 'Younger Dryas' drop in temperature that is well documented in the northern hemisphere, and now also in South Africa.

According to some scientists, this cooling in widespread areas could have been caused by the global dispersal of platinum-rich atmospheric dust after a meteorite hit.

Thackeray's team believes their discovery of a platinum spike at about 12,800 years ago at Wonderkrater is just part of the strengthening view that an asteroid or cometary impact might have occurred at that time.

This is the first evidence in Africa for a platinum spike leading to the mini-ice age of the Younger Dryas.

Younger Dryas spikes in platinum have also been found in Greenland, Eurasia, North America, Mexico and recently also at Pilauco in Chile.

Wonderkrater is the 30th site in the world discovered with evidence of platinum spikes.

Thackeray said: 'Our evidence is entirely consistent with the Younger Dryas Impact Hypothesis.'

The discovery in South Africa is expected to be analysed in context with those made in other parts of the world.

A large crater 31 kilometres in diameter was discovered in northern Greenland beneath the Hiawatha Glacier last year.

Thackery recognises that the source of the platinum at Wonderkrater could hypothetically be cosmic dust that was dispersed in the atmosphere after a meteorite impact in Greenland.

The South African research has been supported by the National Research Foundation and the DST/NRF Centre of Excellence for the Palaeosciences and was published in Palaeontologia Africana.