Superstitionia donensis

Distinguished from other small North American scorpions by: (1) reduced pectinal tooth count (11–15 vs. 20+ in most Vaejovidae and Buthidae); (2) unique trichobothrial pattern with single ventral trichobothrium on fixed finger of chela; (3) family-level placement confirmed by trichobothrial formula on femur and patella. Most similar to small vaejovids but differs in pectinal morphology and trichobothrial arrangement. Geographic restriction to Sonoran Desert region aids identification.

Small scorpion, adults reaching approximately 25–35 mm in total length. Coloration is pale yellow to tan. Pedipalps are slender with fine granulation. Metasoma (tail) is relatively thin with evenly distributed granules. Telson is small and bulbous. Unique trichobothrial pattern on pedipalp chela: a single ventral trichobothrium on the fixed finger (characteristic of the family). Pectines bear 11–13 teeth in females, 13–15 in males—fewer than most other scorpion families. Carapace is smooth with a shallow median furrow.

Rocky desert habitats, particularly in mountainous and hilly terrain with abundant rock crevices and talus slopes. Associated with igneous and metamorphic rock formations. Found under stones and in cracks during daytime. Elevational range approximately 300–1,500 m.

Endemic to the Sonoran Desert region. United States: Arizona (Superstition Mountains, Mazatzal Mountains, and adjacent ranges in central and south-central Arizona). Mexico: Sonora (northwestern portion, extending southward along the Sonoran coastal plain and adjacent inland areas). Records from Baja California require verification.

Active year-round in suitable conditions, with peak surface activity during warmer months (April–October). Winter activity reduced but documented during mild periods. Juveniles observed primarily in late summer and fall.

Nocturnal forager. Seeks shelter under rocks and in crevices during daylight hours. Locomotion is relatively slow compared to more cursorial scorpion species. Defensive posture involves raising the metasoma with telson directed forward; stinging is infrequent unless handled.

Predator of small invertebrates in rocky desert ecosystems. Serves as prey for larger arthropods, reptiles, birds, and small mammals. Contributes to nutrient cycling through predation and scavenging.

Venom is mild and not considered medically significant; stings produce localized pain comparable to a bee sting. Occasionally encountered by hikers and rock climbers in the Superstition Mountains. Of interest to arachnologists due to its phylogenetic position as the sole member of a monotypic family.

• Vaejovis spp.Overlap in size range and general habitus. Distinguished by higher pectinal tooth count (typically 20–30), different trichobothrial patterns, and lack of the single ventral trichobothrium on the fixed finger.
• Paruroctonus spp.Similar small size and pale coloration. Distinguished by different trichobothrial arrangements, pectinal tooth count, and metasomal segmentation patterns.
• Hadrurus spp.Overlap in geographic range. Distinguished by much larger size (adults 80–140 mm), robust pedipalps, and dense setation on metasoma.

• scorpion
• endemic
• Sonoran Desert
• monotypic family
• basal lineage

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life