The identification of bone modifications as stone-tool cut marks rather than carnivore tooth marks or other natural damage requires judgment calls, and different researchers examining the same specimens have sometimes reached different conclusions.

The 2017 paper’s authors placed only 15 specimens in the “confident” human modification category precisely because they wanted to exclude anything ambiguous — but the determination of what counts as confident attribution is itself subject to debate.

Others have raised questions about the dating.

The horse mandible date of approximately 24,000 calibrated years BP is an AMS radiocarbon date from a bone specimen, and bone dates carry specific concerns that collagen dates from other materials may not.

Contamination of the collagen — the protein in bone that is the source of the carbon used in dating — by more recent organic carbon can produce dates that are younger than the actual age of the specimen.