These seem to be from an interesting time period, the warm period during the stone ages just prior to the younger dryas mini-ice age. Also just right up against the boundary of the transition of humans into far more advanced technology including agriculture and animal husbandry. I wonder if they died out due to the onset of harsher climatic conditions or due to being outcompeted by humans at the dawn of civilization.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...