Stanford Hills Trapdoor Spider

Aptostichus stanfordianus, the Stanford Hills trapdoor spider, is a species of wafer-lid trapdoor spider (Euctenizidae) endemic to California in the United States.

In Sonoma County, California

Female described by Smith (1908).

Aptostichus stanfordianus is distributed widely throughout the Coastal Ranges of central California, bounded to the east by the Central Valley (Map 10). The greatest concentration of populations appears to be centered in the Santa Cruz Mountains and the Diablo and Gabilan Ranges with additional populations in the Sonoma and Howell Mountains to the north. The DM for Aptostichus stanfordianus (Map 11) corresponds closely to the known distribution of the species with the exception of areas of high probability of occurrence that overlaps considerably with the predicted distribution of Aptostichus angelinajolieae but likewise is separated from this species by an area of low probability of occurrence across the Salinas Valley. Also, populations found on the eastern facing slopes of the Coastal Range are found in areas of a low probability of occurrence. Like Aptostichus angelinajolieae, this species is found along damp, north-facing steep banks and road cuts. Populations of this species are found in a number of ecoregion types including California coastal chaparral and shrub, coastal range open woodland and shrub, coniferous forest, coastal steppe, mixed forest and redwood forest. Males have been collected early fall through late winter (September–March).