A snail's tale: A geological history of a species.

摘要

A geometric morphometric study was performed on fossil and modern shells of the cone snail species Conus spurius in order to investigate how stable the species' morphology has been over its geological duration and geographical range. Extant C. spurius is widespread in the Gulf of Mexico and Caribbean Sea. This cone snail species also exhibits an extensive fossil record that extends back to the Miocene (~8 Ma). A combination of two landmarks and 62 sliding semilandmarks were used to characterize the shell form of fossil and modern C. spurius. Three morphologically similar species, C. evergladensensis, C. humerosus, and C. spuroides, and three synonymized species, C. martinshugari, C. micanopy, and C. streami, previously were compared with C. spurius. Modern C. spurius shells exhibit a slightly different shell shape than fossil specimens. However, there is not enough variation in shell morphology to recognize fossil and modern C. spurius as separate species. Conus spurius , however, has shown a gradual change in shell shape, suggesting that the species has not been morphologically stable over time.