It is in the source article, and it may just be me, but I question use of the word "fossil" because I don't think these remains have undergone any of the various transformations which cause fossilisation in the geologic sense.
It's counterintuitive, but the term "fossil" doesn't always necessitate fossilization. Basically if the specimen is >10,000 yo (roughly the transition from Pleistocene to Holocene) then it can be referred to as a "fossil". This isn't a hard and fast rule, and seems to depend on the specific field/subfield or even US vs UK, etc.