Chonodesmus muisca, Reyes-Peñata & Romero-Rincon & Martínez-Torres & García-Sarmiento, 2025

Reyes-Peñata, Liseth Alejandra, Romero-Rincon, Juan, Martínez-Torres, Daniela & García-Sarmiento, Martha J., 2025, Two new species of the flat-backed millipede genus Chonodesmus Cook, 1896 (Polydesmida, Cryptodesmidae, Cryptodesmini) from Colombia with a redescription of the type species, Zootaxa 5659 (2), pp. 223-239 : 230-233

Chonodesmus muisca new species

Figs 4–6 , 10 .

urn:lsid:zoobank.org:act:84CFFB85-2025-4B73-ADD0-5258AFB3E63E

Diagnosis. Based on the characteristics of the gonopod, the new species appears to be particularly similar to C. alatus by the presence of reduced tooth-shaped apical processes and a single elongated and slightly curved branch on the anterior lamellar process. It differs from congeners in showing three apical branches of the apical process: two reduced and a central hook-shaped one.

Etymology. Muisca, a noun in apposition. In honour of the Muisca people, an indigenous ethnic group that inhabited the Cundiboyacense region where the species was found.

Material examined

Holotype. COLOMBIA ● ♂; Cundinamarca, San Antonio del Tequendama, Parque Natural Chicaque; secondary forest (4.614554, -74.314338); 2140–2177 m a.s.l.; inside bark of fallen log; daytime hand collection; 25 Jun. 2022. J. Romero-Rincon & R. De La Cruz leg.; MHN-UPN-MD-436.

Paratypes. ● 1 ♂; same locality data as for holotype; on soil; daytime hand collection; 28 Apr. 2022. J. Romero-Rincon leg.; MHN-UPN-MD-131 . ● 1 ♂; same data as for holotype; MHN-UPN-MD-135 . ● 1 ♂; same data as for holotype; MHN-UPN-MD-434 . ● 1 ♂, 1♀, 1 immature; same data as for holotype; MHN-UPN-MD-435 . ● 1 ♂, 1♀; Cundinamarca, San Antonio del Tequendama, Parque Natural Chicaque ; oak forest (4.617432, -74.313801); 2232–2275 m a.s.l.; 08 Jan. 2022. J. Romero-Rincon leg.; MHN-UPN-MD-81 . ● 1♀; same locality data as for preceding; daytime hand collection; 26 Nov. 2021. J. Romero-Rincon leg.; MHNUC-MD-1012 . ● 1 ♂; same locality data as for preceding; under bark of fallen log; night time hand collection; 28 May. 2022. J. Romero-Rincon leg.; MHNUC-MD-1013 . ● 2 ♂♂, 1 immature; same locality data as for preceding; in leaf litter; winkler method; 03 Jun. 2022. J. Romero-Rincon & R. De La Cruz leg; MHN-UPN-MD-134 . ● 1♀; same locality data as for preceding; under bark of fallen log; night time hand collection; 27 Aug. 2022. J. Romero-Rincon leg.; MHN-UPN-MD-137 . ● 2 ♂♂, 2♀♀; Cundinamarca, San Antonio del Tequendama, Parque Natural Chicaque ; 2200 m a.s.l.; 23 Jan. 2015. Myriapodology course leg.; ICN-MD-1256 . ● 2 ♂♂, 2♀♀; Cundinamarca, San Antonio del Tequendama, Parque Natural Chicaque ; oak forest (4.616848, -74.307188); 15-17 Oct. 2016. Spider biology students.; ICN-MD-1757 . ● 2 ♂♂, 2♀♀; Cundinamarca, Tena, Reserva Natural de la Sociedad Civil Tenasucá (4.689573, -74.389288); 2043 m a.s.l.; 7-19 May. 2019. S. Galvis, S. Alvear, J. Homez, D. Martínez-Torres & O. Villarreal leg.; ICN-MD-2071 . ● 2 ♂♂; Cundinamarca, Bogotá - Choachí, Parque Ecológico Matarredonda (4.555269, -73.975575); 3350 m a.s.l.; trail “Cascada de la Abuela”; daytime hand collection; 15 Oct. 2022. D. Martínez-Torres, K. Marimón, P. Martins & J. Alonso leg.; ICN-MD-2519 .

Description

Measurements. Head + 20 rings (including telson), male 12.5 mm long and 3.5 mm wide; female 13.5 mm long and 3.5 mm wide.

Color. Head with epicranium light yellowish pink 28 and spots moderate brown 58; from fronts to labrum pale orange yellow 73. Collum light orange 52. Prozonites and metatergites dark reddish brown 44, paranota with central area light grayish reddish brown 45 with transparent anterior edges. Sternites moderate yellowish pink 29, legs pale yellowish pink 31. Antennae: antennomeres 1–4 light yellowish pink 28, 5–6 moderate brown 58 and 7–8 moderate reddish brown 43.

Head. Head convex, strongly inclined downward and typically covered by collum, slightly setose; setae ca ½ the length of dorsal setae ( Figs 4 , 5B ). Clypeolabral region with very short setae. Epicranial suture faint. Antennae short, reaching posterior part of second body ring when extended backward, stout and claviform; antennomeres V, VI with a compact group of sensilla ( Fig. 4B ). Collum about twice as long as head, anterior and posterior edges as in the congeners; the last about as long as the first prozonite. Its surface covered with a series of tubercles arranged in six transverse lines, anterior zone with a row of lobes varying between 20 and 21, each accompanied by a slender medium-sized seta. Relative length of antennomeres: 5>6>4>2>3>7>1 ( Fig. 4A ).

Trunk. Prozonites short, slender and glabrous, widening slightly towards caudal region. Metazonites broad, metatergites densely hairy and tuberculate, with three rows of tubercles extending transversely to bases of paranota, each tubercle with a long slender seta; setae being equal in length. Paranota broad with lobed distal and basal margins, anterior margin straight and terminating in a setiform tooth-shaped projection, lateral margin with 3 or 4 subtriangular setigerous divisions with a macroseta located at the posterolateral angle and another of similar length at the inner base ( Fig. 4D ). Posterior margin with 7 distinct marginal areas. Ozopores opening flush on surface between the 2nd and 3rd area; ozopore formula normal. On posterior rings, paranota showing caudal projection, these being more pronounced closer to telson. Axial line absent. Sternites slightly wider between posterior pair of legs compared to anterior pairs. Coxae 6 with a pair of small and setose protuberances. Coxae 7 noticeably wider apart than others and excavate. Legs long and slender. Prefemora 7 in males with a conspicuous spine ( Fig. 4E ), a serrate and acuminate leaf blade. Epiproct subtrapezoidal with a short basal area. Medial area with lobed and slightly convex margins, distal area with slightly curved and irregular margins.

Gonopods. Gonopod ( Fig. 6 ) aperture subovoid, with anterior margin almost straight and excavated, posterior margin slender and slightly elevated. Cx prominent and without setae, ventral surface of Cx with median commissure connecting both Cx; ca tubular and of normal structure. Pfe densely setose as usual, similar to that observed in other congeners, setae of greater length adjacent to telopodite. Telopodite robust and highly complex, with apical processes typical of the genus. Posterior lamellar process with three branches arranged from left to right in mesal view: (1) small, sharp and inconspicuous spine-shaped; (2) falcate, oriented basally and (3) tooth-like ca 2/3 length of the second. Anterior lamellar process with a laterally curved and sclerotized branch, increasingly tapered towards apex. S short and thin with a small fungiform process associated to hm with serrated margin and with a medium-sized lobe in the basal area. Lateral surface of telopodite with a densely pilose pad. Seminal groove in basal part of telopodite difficult to observe because of its location behind medial commissure in Gx ventral part.

Female. Non-sexual characters as in males, except for Sternite 7 without modification, prefemora 7 of legs without spine.

Distribution. Known from Parque Natural Chicaque (San Antonio del Tequendama), Reserva Natural de la Sociedad Civil Tenasucá (Tena) and, Parque Ecológico Matarredonda (between Bogotá D.C. and Choachí), Cundinamarca Department, Colombia, 2043-3350 m a.s.l. ( Fig. 10 ).

Figures

FIGURE 4. Chonodesmus muisca sp. nov., male paratype (MHN-UPN-MD-137). A. Habitus in dorsal view. B. Habitus in ventral view. Scale bar: 2 mm.

FIGURE 5. Chonodesmus muisca sp. nov., A, E. paratype (MHN-UPN-MD-135) B, D, F. paratype (MHN-UPN-MD-137) C. holotype (MHN-UPN-MD-436). A. Antenna, posterior view. B. Anterior part of collum, dorsal view. C. Aperture of gonopods, ventral view. D. Left paranotum of ring 10, dorsal view. E. Left leg 7, posterior view. F. Detail of telson, dorsal view. Scale bars: 0.2 mm.

FIGURE 6. Left gonopod of Chonodesmus muisca sp. nov., male holotype (MHN-UPN-MD-436). A, D. Mesal view. B, E. Ventral view. C, F. Lateral view. Abbreviations: ca: cannula, Cx: gonocoxae, hm: hyaline membrane, Pfe: prefemoral region, S: solenomere. Scale bar: 0.5 mm.

FIGURE 10. Distribution map of Chonodesmus Cook, 1896.