Tridenchthoniinae (Balzan, 1892), 1929

Jeong, Kyung-Hoon, Harms, Danilo & Johnson, Jithin, 2024, A new species of Ditha (Pseudoscorpiones, Chthoniidae, Tridenchthoniinae) from the Western Ghats of India, with an identification key for the genus, Zoosystematics and Evolution 100 (1), pp. 1-8 : 1

Subfamily Tridenchthoniinae (Balzan, 1892)

Remarks.

Balzan (1892) proposed the family Tridenchthoniidae to include the species Tridenchthonius parvulus Balzan, 1887 from Paraguay which possessed triple galea in the chelicera. However, Hansen (1894) considered this species to be an unusual Chthonius and reduced the taxon to the subfamily Tridenchthoniinae . Since then, the taxonomic status of the group has undergone several changes. Chamberlin (1929) in his revised classification scheme for pseudoscorpions, proposed a new subfamily Dithinae Chamberlin, 1929 to include the new genus Ditha Chamberlin, 1929. Dithinae chthoniids closely resemble Tridenchthoniinae , except that they include non-galeate forms, but they differ from members of Chthoniinae proper in the characters such as the presence of coxal spines (of single simple type) on coxa I and II and the patella of leg IV being distinctly longer in relation to the femur. Chamberlin (1931) later raised this group to the family status. However, without providing proper justification, Beier (1932) reduced the family to the subfamily status and later to Dithiidae again. However, recognizing Balzan’s species T. parvulus as a Dithiidae member, Chamberlin and Chamberlin (1945) proposed the family Dithiidae as a junior synonym of Tridenchthoniidae . Finally, in a recent study on pseudoscorpion transcriptomics ( Benavides et al. 2019), the group was again reduced to a subfamily within Chthoniidae that now includes Tridenchthoniinae as a subfamily, alongside the Chthoniinae and Lechytiinae .