Mammoths blasted with space material

Laura Clout has this story on The Telegraph about a massive event that took place 35,000 years ago, that is recorded in the remains of bison and mammoths:

Scientists studying the remains of mammoths have found evidence that the animals and other great beasts were blasted with material that came from space.

Eight tusks unearthed in Alaska suggest the animals were hit by fast-flying meteorite fragments during a calamitous event some 35,000 years ago.

Researchers, who have a Siberian bison skull which is similarly peppered with marks, think the explosion may have severely depleted the populations of some species. Richard Firestone from the Lawrence Berkeley National Laboratory told the BBC: "We think that there was probably an impact which exploded in the air that sent these particles flying into the animals.

"In the case of the bison, we know that it survived the impact because there's new bone growth around these marks."

Allen West, a geoscience consultant, added: "If the particles had gone through the skin, they may not have made it through to vital organs. But this material could certainly have blinded the animals and severely injured them."

The mammoth and bison remains are perforated by 2mm holes, surrounded by burnt surface rings where the fragments entered at high speed.

All the punctures are on one side, suggesting the impact came from a single direction, and tests on the embedded particles show they are magnetic with a high iron-nickel content.

The ratios of different types of atoms in the fragments meant it was most unlikely they had originated on Earth, the researchers said....