Abstract
Numerous fossil bones of Naumann's elephant, Palaeoloxodon naumanni (MAKIYAMA) have been unearthed from the Latest Pleistocence sediments of the bottom of Lake Nojiri, northern central Japan (KAMEI & TARUNO, 1973). By the time of the excavation at Tategahana, Lake Nojiri in March of 1973, rather well-preserved stylohyoid bone of Naumann's elephant was newly found. As the occurrence of such proboscidean stylohyoid bone in fossil state is very rare and the first time in Japan, a description in details on that specimen and a comparative study with those of living Asiatic elephant, Elphas maximus and African elephant, Loxodonta africana are given in this paper. For convenience, the stylohyoid bone of the elephant is divided into three parts, and they are nominated as inferior-, superior- and posterior ramus. As a result of study, it has become clear that there are some remarkable morphological differences among those fossils and living materials. Namely, 1) The stylohyoid bone of Naumann's elephant is characteristic in having a distinct and stout process at the dorsal border of the base of the posterior ramus. 2) The stylohyoid bone of African elephant has distinct before and behind expansion at the proximal portion of the inferior ramus. 3) The twisting of the inferior ramus is represented to be the most in the case of the stylohyoid bone of Naumann's elephant.
