Ursus deningeri von Reichenau 1904

Ursus cf. deningeri REFERRED MATERIAL. — NISP 308: cranium fr., 2 maxilla fr. (1/1), mandible fr. (2/0), 20 DI/dI, 2 I fr., 139 dC, 50 dC fr., 6 c1 fr., 2 D4, 3 d4, Pm/pm fr., P4 fr., 2 M/m fr., M1 fr., 2 m 1 fr., 2 humeri fr. (0/2), 5 radii fr. (4/1), 5 ulnae fr. (4/1), 5 femorae fr. (2/3), 8 tibiae fr. (2/6), fibula fr., 8 pelvis fr. (3/5), calcaneus fr., scapholunar fr., left mc 3, right mc 4, mtpd fr., 7 costae fr., atlas fr., 2 cervicale fr., 8 thoracic fr., 2 lumbar fr., 2 vertebra fr., 7 ph 1, 4 ph 2, ph 3 (Appendix 1). DESCRIPTION Numerous cranial and postcranial skeletal elements of bears were recovered from TW. Most of them are the remains of neonate or juvenile specimens and milk teeth, but there are also bone fragments belonging to adult individuals. Considering the percentage of the remains of U. deningeri and U. arctos, the overwhelming number of these bones can be classified as belonging to U. deningeri. However, the lack of clear diagnostic features does not allow attributing these remains to U. deningeri with confidence. For this reason, we decided to put these remains into the group of Ursus cf. deningeri / Ursus sp. REMARKS The analysis of the age structure based on the dentition and postcranial skeleton does not quite correspond to expectations from the TW fauna. In addition to the 0-4 month and 12-14 months juveniles died in winter storage, there is a relatively large group of 7-9 month-old bears that apparently died in the den in summer or autumn. The causes of their deaths are unclear. These young bears might have been killed by carnivores and dragged into the den. Biting marks on the bones are rarely observed, so death by a carnivore attack can only be rarely documented (e.g. Marciszak et al. 2024). In such cases, however, biting of the bones does not necessarily have to be visible. Hunting by humans can neither be proven nor disproved. It is also possible that young died very late, e.g. March instead of January. Then they would already go into hibernation at the age of 7-9 months and have not survived the winter due to a lack of sufficient fat reserves (Marciszak et al. 2024). In general, most juvenile bears died in TW were younger than one year. There are significantly fewer finds of 2-3-year-old bears. Compared to the data from the extant U. arctos, where it states up to 50% mortality for yearlings (Swenson 2000), the age distribution is relatively normal. In the following two years, the mortality rate is lower and increases again strongly in the case of 3-4-year-old bears that have just became independent. For adult U. arctos, a comparatively low mortality rate of 15% was established (Wittenberg & Wenzelides 2000). This corroborates relatively well with the age data obtained for the TW palaeopopulation. The causes of death in adult animals are very variable. Some of the bears from TW certainly died during the hibernation due to insufficient fat reserves or because of diseases. Some bear individuals may have also fallen as prey to other carnivores. If one assumes that the found age structure really reflects the use of the cave, then the TW seems to have been visited by adult bears, and numerous finds indicate a frequent stay or a higher death rate in the cave. This cave was used by cave bears as a hibernating den.