Tyrphonothrus Knülle, 1957

Colloff, Matthew J. & Cameron, Stephen L., 2013, A phylogenetic analysis and taxonomic revision of the oribatid mite family Malaconothridae (Acari: Oribatida), with new species of Tyrphonothrus and Malaconothrus from Australia, Zootaxa 3681 (4), pp. 301-346 : 305-306

Tyrphonothrus Knülle, 1957

Trimalaconothrus (Tyrphonothrus) Knülle, 1957 , p. 160.

Type-species: Trimalaconothrus novus Sellnick, 1921, p. 76 (= T. maior [ Berlese, 1910]) by original designation.

Fossonothrus Hammer, 1962 , p. 20; syn. Subías, 2004, p. 62.

Type species: Fossonothrus latus Hammer, 1962 , p. 20, by original designation.

Definition and diagnosis. Malaconothrid mites with the following combination of characters. Carina strongly incurved anteriorly, S-shaped, broad, enclosing seta le. Seta in typically very long, flagelliform, at least 3–5 × the length of seta ex; never short. Caudal region of hysterosoma typically much broader than anterior region. With centrodorsal ridges and M-shaped posterior ridges, or ridges secondarily lost, as indicated by vestigial structures. Anteriolateral margin of epimeral plates I triangular or rounded. Apodeme IV broad, straight, more or less transverse. Genital setae 5–12 pairs. Tarsi, particularly Tarsus I, elongated, at least 2.5 × longer than maximum width. Setae e 2 and h 2, and occasionally h 1, longer than other notogastral setae in the c -h series. Various combinations of prodorsal, notogastral, epimeral, genital and adanal setae barbed or setae smooth. Setae of tibiae, genuae and femora barbed or smooth; tarsal setae smooth. Pre-tarsi tridactylous.

Remarks. Hammer (1962) did not provide a diagnosis for Fossonothrus , having conflated the description of the genus with that of F. latus , though clearly her intent was to include within Fossonothrus those species with Sshaped carinae, longitudinal ridges on the central notogaster and diagonal ridges on the posterior notogaster, a convex posteriomedian margin to epimere IV and hexagonal genital plates. These are characters shared with Tyrphonothrus Knülle, 1957 and Fossonothrus was considered its junior synonym ( Subías, 2004).

Tyrphonothrus consists of two clades, with Ty. maior (the type of Tyrphonothrus ) in one and Ty. latus (the type of Fossonothrus ) in the other ( Fig. 2 ). It might be seem justifiable to formally recognise the clades as subgenera. However, the characters that separate them relate to the epimeral setal formula and its variations, including the presence or absence of seta 3a (absent in the Ty. maior clade except in Ty glaber ; present in the Ty. latus clade except in T. sacculus ). The epimeral setal formula is a complex character and the absence of any one particular seta may be independent of, or coupled with, the presence or absence of another. Further complicating the issue, the loss of 3a shows a mosaic distribution within the Malaconothroidea, occurring in Mucronothrus , one clade of Tyrphonothrus and in at least eight Malaconothrus spp. belonging to different minor clades. Accordingly, it seems wiser not to create subgenera within Tyrphonothrus until a clearer and more detailed analysis of character states separating the two clades can be undertaken.

Figures

FIGURE 2. Cladogram of selected Malaconothridae showing two major clades, Tyrphonothrus and Malaconothrus. Designations of species to nominate subgenera, Trimalaconothrus (Tyrphonothrus) and Malaconothrus (Cristonothrus) follows Subías (2004). Bold type = species with complete notogastral ridges; * = species with partial ridges; M (M), M (C) = monodactylous; T (T), T (Ty) = tridactylous. Percentage probabilities of each node are indicated if other than 100.