Trhypochthoniidae (Norton, 1998)

Norton, Roy A. & Ermilov, Sergey G., 2024, Evaluation of morphological traits in Trhypochthoniidae with focus on Allonothrus, and morphology-molecule conflict in classification and phylogeny of Nothrina (Acari: Oribatida), Zootaxa 5556 (1), pp. 144-199 : 165

Leg setation in Trhypochthoniidae

General comparison

After studying a wide range of taxa and relevant literature, it is clear that leg setation in Trhypochthoniidae has both significant variety—perhaps more than any other nothrine family—and a unique set of consistent traits that could serve to diagnose the family. Leg setation has been misinterpreted in some literature, largely due to a lack of knowledge of ontogeny, which can be crucial to establishing setal homologies ( Grandjean 1941a; Norton & Ermilov 2014).

The full ontogeny of leg setation has been reported for only four of the seven currently recognized genera: Afronothrus , Mucronothrus , Mainothrus , and Trhypochthoniellus . Fragmentary ontogenetic data for Trhypochthonius have been presented by F. Grandjean in various papers (see Norton & Ermilov 2014), and some data on tarsi of Allonothrus schuilingi and Archegozetes magnus were presented by van der Hammen (1955b), but these are insufficient for detailed comparisons of genera and families. Below, we review the salient aspects of leg setal ontogeny for each of the seven genera. Included are ontogenetic tables for representative species of Allonothrus , Archegozetes and Trhypochthonius .