Reference for Bekhorot 89:37
יתרת שיש בה עצם ואין בה צפורן מטמא במגע ובמשא ואין מטמא באהל
makes a person unclean by contact and by carrying it.<span class="x" onmousemove="('comment',' Where, for example, it has a small quantity of flesh attached to it, even it be less than the size of an olive. For if there were a piece of flesh the size of an olive on the bone, then even if the additional finger were not in line with the rest of the fingers or even if there were not a bone in the additional finger, it would have caused tent uncleanness, for the rule is that the flesh of a corpse the size of an olive causes tent uncleanness. Again, if there were not any flesh at all on the bone, then even if the additional finger were in line with the rest, it would not have been considered a limb, since bones as such do not cause tent uncleanness, unless where there is a majority of the joints or the greater part of the corpse. But now since there is a small portion of flesh, even though not the size of an olive, the additional finger of a corpse causes uncleanness because it is in line with the rest and is legally recognized as a limb.');"><sup>19</sup></span>