Morphological evolution of the cave bear (Ursus spelaeus) mandibular molars: coordinated size and shape changes through the Scladina Cave chronostratigraphy

Out of all extinct megafaunal mammals the Quaternary, cave bear Ursus spelaeus is one best represented in fossil record. This species has been found to exhibit skeletal morphological adaptations when exploiting varied environmental niches, be that spatially or temporally. Here, we employ geometric morphometrics and phenotypic trajectory analysis explore temporal changes across entire lower molar tooth row from infilling Scladina Cave, Belgium. We show size increases Marine Isotope Stage (MIS) 5 – MIS 3, with cusp position varying temporally relation a larger talonid grinding platform later time periods. Phenotypic analyses further similar evolutionary shape trajectories first second molars, but not third molar. Morphological related are divergent change M 3 suggesting this less constrained appears much more responsive changes. The need cope harder fibrous plant material present palaeoenvironment potentially evolution until its disappearance throughout Europe. • Lower 3. Cave changed process material. Tooth powerful ecological tool understand adaptation bears.