Both regular and irregular, i.e., sporadic, absence of the ventral spur (ventral tooth) on the basal cheliceral article has been reported in Oligolophinae. In this contribution, a female Lacinius ephippiatus with one missing ventral spur, and the other partly reduced, on the basal cheliceral article is described. For comparison, we studied chelicerae in a normally developed female from the same locality. We suggest that the ventral spur on the basal cheliceral article is an apomorphic character within Oligolophinae and that its sporadic absence is a case of spontaneous atavism.