Liaoninosoma, Mikhaljova, 2022

Mikhaljova, Elena V., 2022, The millipede family Diplomaragnidae Attems, 1907 confirmed for mainland China, with descriptions of a new genus and new species (Diplopoda, Chordeumatida), Zootaxa 5219 (2), pp. 185-192 : 186

Liaoninosoma gen. nov.

Type and only species: Liaoninosoma marusiki sp. nov., by present designation.

Diagnosis. The genus differs from other genera of the family mainly by the posterior gonopod colpocoxite, which has an independent (separate), broad, longitudinal structure (“pad”) (cp), covered with dense spikes ( Fig. 16 ), with a shallow, partly open-edged sheath groove for the anterior gonopod telopodite together with a rectangular laterally and slightly caudally curved distal part, in combination with a large posterior angiocoxal process.

A structure similar to the above-mentioned “pad” is not observed among all known genera of the family.

Description. Body with 30 rings (including telson). Ommatidia present, fields triangular. Medium-sized paraterga well-developed, horizontal. Male legs 3 and 4 not enlarged. Male legs 5–7 enlarged, coxae with low subconical outgrowths, femora swollen and curved, tarsi very long, sabre-shaped. Male legs 10 and 11 with coxal glands.

Telopodites of anterior gonopods flagelliform, 1-segmented, sheathed. Posterior gonopod colpocoxite with an independent (separate), broad, longitudinal spiky structure (“pad”) (cp) with a shallow, partly open-edged sheath groove for the anterior gonopod telopodite ( Figs 15, 16 ). Colpocoxites fused medially in its basal half; their distal parts curved laterally. Each colpocoxite entire, undivided. Angiocoxites with a subglobule (sg) strongly protruding caudad in posterior view ( Figs 15, 18 ). Angiocoxites (a) in anterior view strongly elongated ventrally, centrally convex along their length, however, they do not form independent, separate processes, but are fused with to colpocoxites ( Fig. 21 ). Anterior angiocoxal processes absent. Posterior angiocoxal processes present. Posterior gonopod telopodites 2-segmented, setose, telopoditomere 1 with a thin stem, telopoditomere 2 of medium length.

Etymology. The generic name refers to the type locality, Liaoning Province. The name is a neuter noun.

Distribution. China: Liaoning Province.

Figures

FIGURES 15–20. Liaoninosoma marusiki sp. nov., two male paratypes (FSCB). 15. Gonopods, posterior view (posterior angiocoxal process on the left removed). 16. Colpocoxite distal part without posterior angiocoxal process, posterior view. 17. Colpocoxite distal part, posterior view. 18. Gonopods, posterior view. 19. Spikes. 20. Gonopods without posterior gonopod telopodites, lateral view. Abbreviations: a, angiocoxite; at, anterior gonopod telopodite; ax, apex; b, mesal blade; ba, frontal blade; cp, colpocoxite “pad’’; ms, spear-shaped structure; p, conical process; pp, posterior angiocoxal process; sg, subglobule. Scales: 10 μm (Fig. 19), 20 μm (Figs 16, 17), 100 μm (Figs 15, 18, 20).

FIGURES 21–25. Liaoninosoma marusiki sp. nov., two male paratypes (FSCB). 21. Gonopods, anterior view (slightly turned to the right). 22. Gonopods, anterior view (slightly skewed backwards). 23. Anterior part of colpocoxite “pad”. 24. Posterior gonopod colpocoxites, anterior view (slightly skewed backwards). 25. Central part of coxosternum of anterior gonopods, anterior view. Abbreviations: a, angiocoxite; bb, blade. Scales: 10 μm (Fig. 23), 20 μm (Fig. 25), 100 μm (Figs 21, 22, 24).