But only a tiny fraction of the meteorites which fall to earth today are carbonaceous chondrites.

ECONOMIST: Paleoforensic science

It is from a class known as the carbonaceous chondrites - primitive, carbon-rich meteorites that contain organic compounds such as amino acids.

BBC: Rare space rock in British lab

Carbonaceous chondrites contain tiny jewels - presolar diamonds and sapphires.

BBC: Rare space rock in British lab

So, if the next meteorite fragments to turn up in rocks from the end of the Cretaceous are also carbonaceous chondrites, the Case of the Dinosaur Killer can probably be closed.

ECONOMIST: Paleoforensic science