Paracortina asciformis Akkari & Stoev, 2023

Akkari, Nesrine, Macek, Oliver & Stoev, Pavel, 2023, A revision of the millipede family Paracortinidae (Diplopoda, Callipodida), ZooKeys 1187, pp. 341-399 : 341

Paracortina asciformis Akkari & Stoev sp. nov.

Figs 5 , 6 , 7 , 27E , 28

Material examined.

Holotype: 1 adult male China, Sichuan Prov., Lixian County, SW of Tonghua Village, 31°33'29"N, 103°19'36"E, 08.07.2012, alt. 1905 m, I. Belousov & G. Davidian leg. (Rd 5347 ZMUM); paratype: 1 adult female, 60 PTs + telson, same data as holotype (Rd 5348 ZMUM).

Etymology.

The species epithet ascia + formis, referring to the distal shape of the telopodite having a shape of an axe in lateral view. Adjective.

Diagnosis.

Different from all other species of the genus Paracortina by the distinctive shape of the distal part of telopodite resembling an axe.

Description.

Length 39 mm, maximal width ca 2.3 mm at PT6; body narrowing anteriorly and posteriorly from PT6; 60 (59 + 1 apodous) pleurotergites + telson. Live colour unknown. Preserved specimen dark brown, metazona dorsally dark brown, especially on crests, laterally and ventrally paler; prozona greyish; legs yellowish (Figs 5A , 6A ). Head: frontal part yellowish, vertex slightly dark brown, antennae yellow (Figs 5C , 6A ).

Fields of ommatidia subtriangular, blackish, composed of ~ 56 transparent ommatidia in eight or nine rows (Fig. 5B ). Organ of Tömösváry ~ 2 × an ommatidium situated close to and touching anterior side of eye. Antennae moderately long (Figs 5C , 6A ). Length of antennomeres (mm): 1 = 0.12; 2 = 0.93; 3 = 0.86; 4 = 0.58; 5 = 0.65; 6 = 0.33; 7 = 0.11. PTs composed of smooth prozona and carinate metazona (Fig. 5D, E ), latter being more pronounced and greater in diameter in the posterior part. Prozona void of crests, anterior part of metazona with low carinae followed by a sharply raising posterior part forming well-developed longitudinal narrow and subparallel crests, well-separated from one another; crests gradually reduce in size laterally and ventrally (Fig. 5C-E ). Chaetotaxy follows the pattern of all setae being in anterior position on PTs 1-4, setae b, c, e migrating posteriorly on PT5 and all setae posteriorly on PT6 onwards. Crests moderately developed, also on collum, comprising alternating primary and secondary series, primary slightly higher than secondary; collum with ca nine crests on each hemipleurite. Ozopores visible from 6th to 59thPT, located on 6th (largest) PT. Hypoproct tripartite, median sclerite largest, subrectangular, bearing a pair of basal macrosetae; lateral sclerites smaller, triangular, with one seta each. Paraprocts divided into large ventral and smaller dorsal sclerites, each pair with a pair of long macrosetae. Spinnerets long and slender, arising from the caudal edge of epiproct and extending well beyond the margins of paraprocts (Fig. 6B ).

Male sexual characters.

Head with a pronounced beak-shaped projection (Figs 6C , 7A ), covered with minute setae. Leg-pairs 1 and 2 reduced and more setose than the rest, leg-pair 2 with a small anterior process and posterior opening of the gonopores, leg-pair 7 with a protruding curved mesal process pointing laterad and a shorter subtriangular one on coxa, trochanter with an anterior triangular projection covered with setae (Fig. 27E ) Coxal sacs present (noticeable) on leg-pairs 3-13/16.

Gonopods. Parallel, each gonopod with two short, slender, clavate, asymmetrical, and apically setose prefemoroidal processes pf1 and pf2 (Fig. 7B-D ); coxa with a low rounded lobe on the anterior margin (Ca), one long falcate mesal coxal process (b), reaching the distal part of the telopodite, its distal part showing ca four beaded structures (Fig. 6C ). Telopodite (T) stout, with a broad stem proximally, gradually narrowing until its distal third before expanding in two main darkly pigmented parts separated by a rounded notch (n), the larger part axe-shaped (Fig. 7C, D ), showing a round apical margin and a sharp triangular opposite end (k), second part as a slender curved stem, apically bifurcated in solenomere (s) and parasolenomere (ps) and bearing a smaller subapical triangular tooth (M) (Fig. 7 ).

Distribution.

Known only from its type locality (Fig. 28 ).

Figures

Figure 5. Paracortina asciformis Akkari & Stoev, sp. nov. A, B, D, E Female paratype (Rd 5348 ZMUM) A anterior body lateral view B head left side, organ of Toemoesvary, and ommatidia C male holotype (Rd 5347 ZMUM) head and anterior pleurotergites, lateral view D, E midbody pleurotergites, D lateral view E dorsal view.

Figure 6. Paracortina asciformis Akkari & Stoev, sp. nov., male holotype (Rd 5347 ZMUM) A head and anterior pleurotergites, frontal view B telson and posterior part of body, posterolateral view C right gonopod mesal coxal process and distal part of telopodite, posterior view. Abbreviations: b = falcate mesal process of coxa; M = mesal process of the distal part of telopodite; s = solenomere; T = telopodite.

Figure 7. Paracortina asciformis Akkari & Stoev, sp. nov., 1 male holotype (Rd 5347 ZMUM), right gonopod A anterior view B posterior view C lateral view D mesal view. Abbreviations: b = falcate mesal process of coxa; Ca = anterior lobe of coxa; pf 1 = prefemoroidal process 1; pf 2 = prefemoroidal process 2; k = lateral process of the distal part of telopodite; M = mesal process of the distal part of telopodite; n = notch on the distal part of the telopodite; ps = parasolenomere; s = solenomere; T = telopodite.

Figure 27. Modifications on leg-pair 6 and leg-pair 7 in adult males of species of Paracortinidae A, B Paracortina viriosa (Wang & Zhang, 1993), male A leg pair 6 B leg pair 7 C, D Paracortina voluta Wang & Zhang, 1993, male C leg pair 6 D leg pair 7 E Paracortina asciformis Akkari & Stoev, sp. nov., male holotype, leg pair 7 F Paracortina kabaki Akkari & Stoev, sp. nov., male holotype, leg pair 7 G Scotopetalum chinensis (Stoev & Geoffroy, 2004) comb. nov., male paratype, leg pair 7. Abbreviations: c = coxa; pr = prefemur; tr = trochanter.

Figure 28. Distribution map of Paracortinidae in China and Vietnam.