When gathering data from the ancient remains it is important to know how many individuals we are dealing with. If not, we risk sampling the same individuals several times and could end up piecing together the history in the wrong way.
In many archaeological sites, the bone remains are severely fragmented and also degraded. It is usually very hard to piece together the fragments and infer the number of individual animals in a collection. Scientists have spent decades trying to figure out how to best deal with this problem and have come up with various solutions to statistically infer this number, but often with large uncertainties.
The ice is an excellent medium for preserving organic remains of ancient fauna, but neither here do everything frozen within it stay intact. Large antlers and bones are sometimes broken into smaller pieces, likely due to the pressure of the ice, and scattered over several meters when the ice melts. In contrast to bones found in the soil, the fragments are rarely much degraded. The fragments can thus usually be fitted together fairly easy and reveal a more intact piece of the puzzle.