Mitchell, 1971

This family includes 4 genera and 11 species [Updated 22.12.14]. The members of this special family have previsouly been placed in different families, and most recently in the family Superstitioniidae. In a recent revision of the troglomorphic North Amercian scorpions, Vignoli & Prendini (2009) reinstated the family Typhlochactidae Michell, 1971. A new genus, Stygochactas was created to accomodate the species S. granulosus (Sissom & Cokendolpher, 1998), previously included in Typlochactas.

Typhlochactids are some very interesting scorpions, all of of them being troglomorphic (e.g. having reduced pigmentation and/or missing eyes) and some being troglobites living in caves). The family is endemic to eastern Mexico. In addition to lacking eyes and pigmenttation, the scorpions of the family are also characterized by having a reduction of sclerotization and carination, attenuation of appendages (legs and pedipalps), loss of spurs and and spinules on legs, enlargement og telson etc. The size varey from very small (Typhlocahctas mitchelli and T. sylvestris with less than 10 mm) to large (Alacran with lenght of 60-70 mm).

Most species have been found in caves (One species has actually been found at depths of about 720-916 meters below the surface). A few species have been found under stones or burried in leaf litter.

No species in this family has been reported to occur in captivity.

No data has been found about the venom of these scorpions.

Vignoli V, Prendini L. Systematic revision of the troglomorphic North American scorpion family Typhlochactidae (Scorpiones, Chactoidea). Bulletin of the American Museum of Natural History. 2009; (326):1-94. (Free fulltext)

Santibanez Lopez C, Francke OF, Prendini L. Shining a light into the world's deepest caves: phylogenetic systematics of the troglobiotic scorpion genus Alacran Francke, 1982 (Typhlochactidae : Alacraninae). Invertebrate Systematics. 2014;28:643-64.

Left: Alacran tartarus photo by Robert Mitchell (C).
Right: Sotanochactas elliotti photo by Robert Mitchell (C).


Alacran Francke, 1982 (3)
A. chamuco Francke, 2009*
A. tartarus Francke, 1982
A. triquimera Santibanez-Lopez, Francke & Prendini, 2014*
Sotanochactas Francke, 1986 (1)
S. elliotti (Mitchell, 1971)
Stygochactas Vignoli & Prendini, 2009* (1)
S. granulosus (Sissom & Cokendolpher, 1998)*s
Typhlochactas Mitchell, 1971 (6)
T. cavicola Francke, 1986
T. mitchelli Sissom, 1988
T. reddelli Mitchell, 1968
T. rhodesi Mitchell, 1968
T. sissomi Francke, Vignoli & Prendini, 2009*
T. sylvestris Mitchell & Peck, 1977

Jan Ove Rein (C) 2024