Patterns of change in shell width over a period of 35,000 years are documented in three fossil land snail species, Euhadra pachya (Pilsbry, Phaeohelix phaeogramma (Ancey), and Coniglobus mercatorius daemonorus (Pilsbry) on the island of Kikai in the Ryu-kyu Islands of the southwest part of Japan. The shell width of these species fluctuated through time, and the patterns were mostly synchronized among the three species. The temporal variations in shell width among fossil populations were far larger than geographical variations in shell width among modern populations. Since Kikai Island has been isolated from the other islands in the region, these morphological changes are regarded as genuine changes that have occurred within the island. The temporal changes in width were accompanied by distinct changes in spire indexj (height/width) within a single species. The patterns of change in width are correlated with the pattern of change in the climate since 35 Ka (35,000 years ago).
|Number of pages||8|
|Journal||American Malacological Bulletin|
|Publication status||Published - 1999|
- Body size
- Kikai island
- Land snail
- Shell morphology