This is very weird. Researchers at the fall meeting of the American Geophysical Union announced the discovery:
The mammoth and bison remains all display small (about 2-3mm in size) perforations.
Raised, burnt surface rings trace the point of entry of high-velocity projectiles; and the punctures are on only one side, consistent with a blast coming from a single direction.
Viewed under an electron microscope, the embedded fragments appear to have exploded inside the tusk and bone, say the researchers. Shards have cut little channels.
The sunken pieces are also magnetic, and tests show them to have a high iron-nickel content, but to be depleted in titanium.
The ratios of different types of atoms in the fragments meant it was most unlikely they had originated on Earth, the team told the AGU meeting.
The BBC article goes on to point out that:
The intriguing question is how space impacts might fit into the extinction story of the ice age beasts. The mammoth, their elephant cousins the mastodon, sabre-toothed tigers, some bears, and many other creatures all disappeared rapidly from the palaeo-record about 10,000 years ago.
Their loss has traditionally been put down to either climate change and/or the efficient hunting technologies adopted by migrating humans.
Could impacts have also weakened these populations?
Maybe it also affected Clovis peoples? That seems to be the gist of this session anybody have any further details?