Rothelix warnerfontis

Warner Springs Shoulderband

Family: Xanthonychidae · Class: Gastropoda · Order: Stylommatophora

Conservation status: G1 S1

The Warner Springs Shoulderband is a terrestrial gastropod mollusk in the family Xanthonychidae, endemic to California. This land snail belongs to the genus Rothelix, which comprises four species according to U.S. Fish and Wildlife Service taxonomic records. The physical characteristics of this species have not been comprehensively documented in available scientific literature, reflecting the limited research conducted on many rare gastropod species. Rothelix warnerfontis is known only from Warner Springs in San Diego County, California, representing an extremely restricted range that contributes to its conservation concern. The species' common name directly reflects its type locality at Warner Springs, a small community in the northern portion of San Diego County. This narrow endemic distribution places the species among California's most geographically restricted mollusks. Specific habitat requirements for the Warner Springs Shoulderband have not been well documented in available literature. Like other members of the Xanthonychidae family, this species likely inhabits terrestrial environments with appropriate moisture regimes and vegetation cover necessary for gastropod survival. The Warner Springs area is characterized by chaparral and oak woodland habitats at moderate elevations, though the precise microhabitat preferences of R. warnerfontis remain poorly studied. Ecological information regarding diet, reproduction, and seasonal activity patterns is largely lacking for this species. Most terrestrial gastropods feed on decomposing organic matter, fungi, and plant material, and many exhibit seasonal activity patterns corresponding to moisture availability. However, specific behavioral and ecological data for the Warner Springs Shoulderband would require dedicated field studies that have not been conducted or documented in accessible scientific literature. The conservation status of Rothelix warnerfontis reflects significant concern for its long-term persistence. NatureServe has assigned the species a Global Status of G1, indicating it is critically imperiled with typically 5 or fewer occurrences or very few remaining individuals. The corresponding S1 state ranking indicates the species is critically imperiled within California. This ranking system suggests the Warner Springs Shoulderband faces a high risk of extinction due to extreme rarity and restricted range. The species appears on the U.S. Fish and Wildlife Service taxonomic database, indicating federal recognition of its taxonomic validity, though it does not currently hold federal listing status under the Endangered Species Act as of December 2025. The primary conservation challenges facing this species likely include habitat loss or degradation within its extremely limited range, potential impacts from development or land use changes in the Warner Springs area, and the inherent vulnerability associated with having such a restricted distribution. Small population sizes and limited dispersal capabilities typical of land snails make recovery difficult once populations decline. Conservation of this species would require protection of its habitat at Warner Springs and comprehensive surveys to better understand its current population status and ecological requirements.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.