Key to species with single large dental spine in T. ocreatus group

1. Body colour grey; anterior area of head with 2, 0 macrochaetae; cave-dwelling species........ T. leyensis Yu & Deharveng

- Body colour yellow; anterior area of head with 2, 4 macrochaetae; surface-dwelling species.......................... 2

2. Antennae subequal to body in length, being 0.9–1.0× length of body; manubrium with 1+1 blunt dorsal chaetae.............................................................................................. T. paraspinulus sp. nov.

- Antennae shorter than body, being 0.6–0.75× length of body; manubrium without blunt dorsal chaetae.................. 3

3. Dens basally with blunt chaeta; denticles on dental spines unevenly distributed................. T. pseudospinulus sp. nov.

- Dens basally without blunt chaeta; denticles on dental spines evenly distributed........... T. spinulus Chen & Christiansen