I'm thinking it was petrified in the permafrost like the mammoths they've been finding the last 20 years or so.
Kind of what I was thinking as well. Which means it is not millions of years old, more in the lower thousands.
That's what I was thinking......besides the diamond ore was formed in a high pressure, high temp and high speed volcano......it would not have preserved any fossils.
Gonna take a wild guess and say this was a siberian weasel (look at the paws, long body), Siberian weasel skull. Siberian Weasel (Mustela sibirica) | Skulls Unlimited 1-800-659-SKULL