Age re-assessment of the cave bear assemblage from Urşilor Cave, north-western Romania

Abstract

The most common methods used for assessing the relative age of a cave bear bone assemblage are the P4/4 index (morphodynamic index of the cave bear fourth premolar), the K-index, and the Index of Plumpness (both used for cave bear’s2nd metatarsal). Preliminary work on these indexes, for Urşilor Cave (NW Romania), has indicated one of the youngest European cave bear populations. As the number of extracted fossil bones from the palaeontological excavation increased recently, a re-assessment of the of the age of the cave bear assemblage is necessary. 206 cave bear fourth lower and upper premolars and 587 metapodials were analyzed. The P4/4 morphodynamic index, the K-index and the Index of Plumpness were calculated for the local MIS 3 cave bear bone assemblage. The results of the three indices have lower values when compared with the previously obtained for the same site and respect the subsequent radiometric ages (ca. 47-39 ky BP). However, the results for P4/4 morphodynamic index, K-index, and Index of Plumpness are of lesser relevance when used to assess the relative age of MIS 3 cave bear bone assemblages. All three methods require caution when applied and interpreted on short time intervals and on smaller geographic areas.