Yia, Enghoff, 2016

Enghoff, Henrik, 2016, A mountain of millipedes V: three new genera of Odontopygidae from the Udzungwa mountains, Tanzania (Diplopoda, Spirostreptida, Odontopygidae), European Journal of Taxonomy 221, pp. 1-17 : 9-10

Yia gen. nov.

urn:lsid:zoobank.org:act:A986C43A-6B7D-45DB-BD61-FD714D2F53E1

Type species

Yia geminispina gen. et sp. nov.

Other included species

None.

Diagnosis

A genus of Odontopygidae-Prionopetalini characterized by: a metaplical shelf (ms) with a curved spine (msp) on the coxa (shared with the Chaleponcus dabagaensis group, see Enghoff 2014) – a compact torsotope (tt) – lack of pretorsal or torsal spines/processes – a pronounced posttorsal narrowing (pn) without spines – a division of the telopodite into solenomere (slm) and telomere (tlm) immediately distal to posttorsal narrowing – a pair of long spines (ts1, ts2) emerging from the base of the telomere – a slender, whiplike solenomere – a very long, slender distal telomeral process (tdp) with a row of long Y- or I-shaped spikes along one edge and an extensively spinose tip.

Etymology

The name is an artificial word and refers to the row of Y- and I-shaped spikes on the gonopod telomere ( Fig. 6F ). To be treated as feminine.

Remarks

In the key of Kraus (1966) Y. geminispina gen. et sp. nov. runs to Odontopyge Brandt, 1841 . As explained by Hoffman (1991) and Enghoff (2016a) this name has been misapplied, and species classified in Odontopyge by pre-1991 authors need to be re-allocated. This is an ongoing process, but the type species of Yia gen. nov. cannot be accommodated in any of the genera which have so far absorbed former Odontopyge species (see Enghoff 2016a). I therefore propose a new genus. None of the still orphaned ex- Odontopyge species share the diagnostic characters of Yia gen. nov., which thus remains monotypic for the time being. Geotypodon heteromodestus ( Kraus, 1960) (= Haplothysanus modestus Attems, 1953 , preoccupied) shares the double telopodital spine characteristic of Yia gen. nov., but differs strongly in several other characters including the structure of the telomere. A very long, very slender distal telomeral process is found in some other odontopygids, e.g., all species of Allantogonus Attems, 1912 ( Kraus 1960) and Prionopetalum Attems, 1909 ( VandenSpiegel & Pierrard 2009; Enghoff 2016b), but these genera differ from Yia gen. nov. in other characters, and no other species has the row of long Y- or I-shaped spikes characteristic of this genus. The metaplical shelf and spine resemble a similar structure in the Chaleponcus dabagaensis group ( Enghoff 2014), but in Yia gen. nov. the spine originates between the shelf and the apical metaplical hood, not from the shelf itself as in the C. dabagaensis group. Also the apical metaplical cucullus (cu) resembles the C. dabagensis group. Yia geminispina gen. et sp. nov. also shows specific similarities with species of the genus Trichochaleponcus Attems, 1928 : the general shape of the coxa, the presence of two spines originating at the base of the telomere, and the tip of the telomere being drawn out into a slender arm. Notable differences include the limbus which is very narrow in Yia gen. nov., very broad in Trichochaleponcus , the absence of a posttorsal, pre-narrowing spine as well as of microtrichose areas on the telomere in Yia , and the unique Y-shaped spicules on the telomere tip in Yia . See also Table 1 . The peculiar course of the pro-metazonal suture seen in Yia geminispina gen. et sp. nov. has so far not been observed in any other odontopygid.

Figures

Fig. 6. Yia geminispina gen. et sp. nov., holotype. Left gonopod telopodite. A. Posterior, slightly basal view. B. Anterior, slightly basal view. C. Anterior, slightly basal view. D. Basal view. E–F. Detail of margin of telomere. F. Tip of telomere. Abbreviations: ba = basomere, pn = post-torsal narrowing, slm = solenomere, tdp = telomeral distal process, tlm = telomere, ts1, ts2 = telomeral spines, tt = torsotope. Scales: A–D = 0.1 mm; F = 0.05 mm; E = 0.005 mm.