Carolinea 74

92 Carolinea 74 (2016) In the nymphs of Tokukobelba compta the seta c3 in contrast is extremely elongate (Fig. 10), with a length exceeding the width of the notogaster, and very roughly of the same length as the long setae c1, c2, la and lp. This character state is un- known in other Damaeidae, where the seta c3 of the nymphs is always regressed and very much shorter than c1, c2, la and lp. A short nymphal seta c3 appears to be a highly conserved derived character state of the Damaeidae when com- pared to various brachypyline outgroups. A reduced tiny seta c3 in nymphs is charac- teristic of Belba species such as B . corynopus ( S enicza k & S enicza k 2013, pers. obs.), B . sculpta (pers. obs.), B . ( Protobelba ) californica ( N orton 1979c), and B . clavasensilla ( N orton & P alacios - V argas 1982). A very short thin seta c3 in the nymphs has, for example, also been described for Caenobelba alleganiensis ( N orton 1980), Quatrobelba montana ( N orton 1980), Lanibelba pini ( N orton 1980), Dyobelba carolinensis ( N or - ton 1979c), Dyobelba reevesi ( N orton & R ya binin 1994), Porobelba spinosa ( G randjean 1954, E r - milov & L ochynska 2009), Spatiodamaeus verti­ cillipes ( S eniczak et al. 2013), Weigmannia parki ( M iko & N orton 2010) as well as in several spe- cies of each of the genera Metabelba ( E rmilov 2010b, E rmilov et al. 2010a, S eniczak & S eniczak 2013), Metabelballa ( E rmilov & K haustov 2011, S eniczak & S eniczak 2013), Damaeus ( N or - ton 1978a, S eniczak & S eniczak 2011), Kunsti­ damaeus ( M iko & M ourek 2008) and Epidamae­ us ( B ulanova - Z achvatkina 1957, N orton 1979c, E nami 1992, E rmilov & L ochynska 2009, S eniczak et al. 2013). In nymphs of most other Eupheredermata such as in Fosseremus quadripertitus ( G randjean 1965a) and Amerus troisi (pers. obs.), there are no pronounced length differences between se- tae c1, c2, c3 and la. However, seta c3 may be minute and the neighbouring setae normal sized as in Polypterozetes cherubin B erlese , 1916, ( G randjean 1959a), or seta c2 instead of c3 may be very strongly reduced in size, as in two spe- cies of Gustavia K ramer , 1879, ( E rmilov 2010a, E rmilov et al. 2013). The strongly developed and elongate seta c3 of nymphs of Tokukobelba may be perceived of as being an autapomorphy of the genus that evolved within the Damaeidae but more likely may be interpreted as Tokukobelba retaining a more ancestral brachypyline charac- ter state, compared to which the minute seta c3 of other Damaeidae is derived, suggesting an outgroup relationship of Tokukobelba to these. Position of Tokukobelba An attempt to unravel the detailed phylogeny of Tokukobelba is a challenging endeavour and is limited by our presently very incomplete knowl- edge of the evolution of the Damaeidae and of the Higher Oribatida in general ( N orto n & B ehan - P elletier 2009), by the substantial limitations im- posed by the methodology of phylogenetic analy- sis and also by the scarce fossil record. The only pre-Pleistocene damaeids known so far have been collected in Baltic amber from the Middle Eocene ( S ellnick 1931, P erkovsky et al. 2007) while the oldest specimen of Tokukobelba known dates to the Quaternary ( D unlop et al. 2016). It is a thorny issue to suggest a sister taxon for Tokukobelba within the Damaeidae. The mor- phological gap between Tokukobelba and other representatives of its family is substantial, much more so than that between any other damaeid genus and its morphologically most similar neighbour. Tokukobelba differs greatly from other damaeid genera in the presence of the exceptionally rare character states: femur III mostly with 3, and fe- mur IV with 2 setae; tibial associated setation mostly 1-1-1-1; tarsal setation 22-18-17-14; tarsus IV with a regressed seta d and elongate tactile solenidion; prodorsal tubercles Aa and Ap both present; palptarsus without seta sul and with a supernumerary ventral seta; interbothridial protuberance present; epimeral setation 3-1-3-3; all epimeral seta usually associated with great- ly enlarged tubercles and huge apophysis E4a present; ventral apophyses Va and E2a conspic- uously multituberculate; epimeral grooves III and especially IV, as well as their apodemes strongly developed; epimeres and lateral prodorsum with verrucose sculpturing; nymphal seta c3 elongate. These traits together with those shared with Belba result in a combination of generic defining characters for Tokukobelba with a very high de- gree of uniqueness, which not only very strongly argues in favour of the monophyly of the group, but also justifies giving this a name. The above unusual character states of Toku­ kobelba may conceivably all have arisen within the Damaeidae, with the genus not being basal to the other damaeid genera. In this case, all of these traits would most parsimoniously have to be interpreted as being autapomorphies of the genus. However, the tibial associated setation of 1-1-1-1, the epimeral setation of 3-1-3-3, the reduced setal count on femur IV and the non re- gressed nymphal seta c3 of Tokukobelba are all