The Afrotropical tardigrade fauna is insufficiently studied, and consequently its diversity in this region is severely underestimated. Ongoing sampling in the Udzungwa Mountains, Morogoro Region of Tanzania has revealed a new representative of the genus Echiniscus C.A.S. Schultze, 1840 (Echiniscidae). Echiniscus tantulus sp. nov. belongs to the spinulosus group, but it stands out from other members of this speciose Echiniscus Glade by having a heteromorphic sculpture of the dorsal plates and an uncommonly stable body appendage configuration A-C-C-d-D-d-E. The new species is characteristic by being equipped with long dorsal spines and very short lateral spicules, which so far have been found only in one other species of the group, Echiniscus spinulosus (Doyere, 1840). An updated checklist of Tanzanian Echiniscidae is provided, incorporating recent advances in their classification.