World It was one of the most extreme periods of global warming in our planet’s history, producing a sudden change in conditions that led to the first primates appearing on Earth.
Now, new evidence suggests the trigger for this sudden rise in global temperatures may have been a large meteorite or comet that smashed into the Earth and caused widespread wildfires.
Geologists claim to have found debris from the impact 56 million years ago scattered across North America along with heavy charcoal deposits as the material thrown outwards set forests alight.
Researchers estimate the blazes resulted in an increase in erosion that saw huge amounts of sediment being washed into the ocean.
This is thought to have triggered a mass extinction that wiped out 4060 per cent of deep sea creatures living on the ocean floor but also brought a boom to plankton near the ocean surface.
The mammals also enjoyed great success, appearing in Europe and North America for the first time.
It is thought many new mammalian forms of life including horses and our own branch of the evolutionary tree, the primates, appeared around this time.
According to the new studies, which were presented at the Geological Society of America in Denver Colorado, we may owe our presence here to a meteor impact just a few million years after one wiped out the dinosaurs 66 million years ago.
It suggests that we may owe our success to not just one meteorite impact, but two.
Dr Morgan Schaller, a geologist Rensselaer Polytechnic Institute in Troy, New York, who led the study, told Science News: ‘The timing is nothing short of remarkable.’
Global surface temperatures are thought to have soared by as much as 11°F (6°C) from the late Pleocene into the early Eocene period.
There are several theories that aim to explain what triggered this dramatic change including massive volcanic eruptions, a mass burning of peat or release of methane gas from ocean sediments.
But the new research presented by Dr Schaller and his colleagues points to a large meteorite or comet impact.
They found glassy spheres made mainly from silica up to 10 inches across in the sediment of the Atlantic margin off the east coast of the US.