Chronospatial variation of dental size of Holocene Japanese wild pigs (Sus scrofa leucomystax)

摘要

The lower teeth of the Japanese wild pigs (Sus scrofa leucomystax) from various geographical locations both archaeological and modern were investigated. Buccolin-gual measurements of the lower third and fourth premolars, and first and second molars are used to compare the regional and temporal differences in dental size of pigs in the Japanese Archipelago.rnSimilar geographical variations in size of Jomon and modern wild pigs in Japan are observed in our study. The size of pigs from northern localities are larger compared to those from southern localities. Populations from Kyushu are distinctively small in dental size compared to the Honshu in both the Jomon and modern populations.rnA different pattern is observed in the Yayoi samples. The pigs from the Yayoi Period show a west-east cline in their size where the populations in the west being larger than those of east. Interestingly to note is that the size of pigs are significantly different between the sites in the northern Kyushu as well as in the western Honshu. The variation in a single region exceeds the geographical variations observed in the Jomon or in the modern samples. We can supose that most of these individuals were brought in from outside the Archipelago. It is a necessity to understand the variation of the modern and archaeological pigs in the Asian continent in order to further discuss the issue morphometrically.%日本列島の本州，四国，九州に生息するニホンイノシrnシ（Sus scrofa leucomystax）の下顎骨臼歯サイズの地理rn的多様性と時間的変化について検討した．分析に用いたrn資料は，本州，九州より得られた現生資料と，縄文時代rnから平安時代の考古遺跡から出土したイノシシ骨であrnる．分析では，下顎第3，第4小臼歯の頬舌径および第rn1，第2大臼歯の頬舌径を使用した．現生資料群と縄文時rn代の資料から，列島の東ではイノシシの臼歯サイズが大rnきく，西にいくにつれて小さくなる傾向が認められた．rn九州の個体群は，現生・考古資料ともに本州に比べて顕rn著に小さい．rn一方，弥生時代においては列島の西でイノシシの臼歯rnサイズが大きく，東で比較的小さい傾向が認められた．rnまた，北部九州および本州西部では，遺跡間で臼歯サイrnズに顕著な差が認められ，その変異幅は縄文時代およびrn現生資料の地理的変異幅を超える．弥生時代におけるこrnのような傾向の背景には，特定地域のイノシシを人為的rnに移動させるなどの影響があったことが想定される．