Aneides flavipunctatus, a terrestrial plethodontid salamander, is virtually restricted to humid, thermally equable areas of northwestern California. The limits of distribution mainly reflect the extent of climatically favorable habitat and the presence of longstanding barriers to dispersal, but competition with other species of salamanders may play a role in excluding A. flavipunctatus from mesic, equable areas in the vicinity of the California-Oregon border.Aneides flavipunctatus exhibits marked ontogenetic and geographic variation in color pattern and external proportions. Within the contiguous portion of the range, variation in individual characters tends to be clinal and correlated with latitude, distance inland, elevation, or other geographic parameters. However, isolated populations at the southern and northeastern limits of distribution exhibit discordant variation relative to their nearest neighbors within the contiguous range.Northern populations of A. flavipunctatus retain a suite of juvenile-like characteristics throughout adulthood, and paedomorphism appears to be an important mechanism by which evolutionary changes have occurred in this species. A Prim Network analysis indicates that phenetic and geographic proximity are highly correlated within the contiguous range of A. flavipunctatus, but that peripheral isolates most clearly resemble central “core” populations in morphology.
