Desmoxytes corythosaurus Srisonchai, Enghoff & Panha
Srisonchai, Ruttapon, Enghoff, Henrik, Likhitrakarn, Natdanai & Panha, Somsak, 2018, A revision of dragon millipedes I: genus Desmoxytes Chamberlin, 1923, with the description of eight new species (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 761, pp. 1-177: 1
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|Desmoxytes corythosaurus Srisonchai, Enghoff & Panha|
Desmoxytes corythosaurus Srisonchai, Enghoff & Panha sp. n. Figs 23, 24, 25, 26, 27, 28
Male (CUMZ), THAILAND, Surat Thani Province, Phanom District, Ban Song Phi Nong, huge limestone mountain, 8°50'51"N, 98°44'16"E, ca. 74 m a.s.l., 7 August 2014, leg. C. Sutcharit, R. Srisonchai and ASRU members.
5 males, 1 female (CUMZ), 1 male (ZMUC), same data as holotype.
not paratypes, all from THAILAND, Surat Thani Province, Phanom District: 1 male, 2 females (CUMZ), Wat Tham Wararam, 8°53'07"N, 98°40'01"E, ca. 51 m a.s.l., 5 August 2014, leg. C. Sutcharit, R. Srisonchai and ASRU members. 1 male, 1 female (CUMZ), Wat Tham Wararam, 8°53'07"N, 98°40'01"E, ca. 51 m a.s.l., 6 August 2016, leg. C. Sutcharit, R. Srisonchai and ASRU members. 1 male, 1 broken female (CUMZ), Wat Tham Wararam, 8°53'07"N, 98°40'01"E, ca. 51 m a.s.l., 1 August 2017, leg. C. Sutcharit and A. Pholyotha and ASRU members. 2 males, 1 female (CUMZ), Tham Nam Lod, near Anurak Community Lodge Resort, big limestone mountain, 8°52'43"N, 98°40'50"E, ca. 51 m a.s.l., 7 August 2014, leg. C. Sutcharit, R. Srisonchai and ASRU members.
The name is a Latin noun in apposition, referring to the similarity of the lamina lateralis (ll) to the crest-liked structure on the head of the dinosaur genus Corythosaurus .
Body dark brown to black; paraterga with brown or black patches contrasting against whitish at base and along the edges; metaterga 2-18 with rows of 2+2 anterior and 2+2 posterior tubercles. Similar in these respects to D. terae , but differing by having paraterga much longer and higher; sternal lobe between male coxae 4 subtrapeziform; male femora 5 and 6 modified; lamina lateralis (ll) apically crest-like; distal lobe with one very long lamella; indentation between distal lobe (dlm) and broad lobe (blm) inconspicuous.
SIZE: Length 32-33 mm (male), 33-34 mm (female); width of midbody metazona ca. 2.3 mm (male), 3.0 mm (female). Width of head < collum < body ring 2 < 3 = 4 < 5-16, thereafter body gradually tapering towards telson.
COLOUR (Fig. 23 A–D): In life with body brownish black; antenna and head dark brown (except distal part of antennomere 7 and antennomere 8 whitish); metaterga and surface below paraterga brownish black; paraterga whitish, dorsally with brown patches in the middle; legs, sterna and epiproct brown; a few basal podomeres sometimes whitish.
ANTENNAE (Fig. 24D): Moderately long and slender, reaching to the posterior end of body ring 6 (male) and 5 (female) when stretched dorsally.
COLLUM (Fig. 24A): With 1 transverse anterior row of 3+3 setae; paraterga of collum low, elevated at ca. 10°-15°, directed caudolaterad, with two distinct notches on lateral margin.
TEGUMENT: Moderately shining and smooth; prozona finely shagreened; collum, metaterga, surface below paraterga, sterna and epiproct smooth; lateral surface at base of paraterga with wrinkles.
METATERGA (Fig. 24 A–C): With 2 transverse rows of setae and tubercles, mostly inconspicuous; metaterga 2-18 with 2+2 anterior and 2+2 posterior tubercles; metatergum 19 with 2+2 anterior and 2+2 posterior setae.
PARATERGA (Fig. 24E, F): Directed caudolaterad on body rings 2-17, elevated at ca. 30° (male) 25° (female); directed increasingly caudad on body rings 18 and 19; tip of paraterga in female slightlty curved caudad; anterior margin with 2 distinct notches, without a tiny denticle near the tip.
TELSON (Fig. 25 C–G): Epiproct: tip subtruncate; lateral setiferous tubercles and apical tubercles inconspicuous. Hypoproct subtrapeziform; caudal margin round, with very small and inconspicuous setiferous tubercles.
STERNA (Fig. 26): Cross-impressions shallow. Sternal lobe between male coxae 4 subtrapeziform; tip usually slightly round (in some specimens subemarginate), base broad and stout.
LEGS (Fig. 25 H–J): Long and slender. Male femora 5 and 6 strongly humped ventrally in middle portion (hump of male femora 6 more developed than 5).
GONOPODS (Figs 27, 28): Coxa (cx) longer than prefemur. Cannula (ca) somewhat stout. Telopodite erect. Prefemur (pfe) ca. 2/3 as long as femur. Femur (fe) quite long and slender. Mesal sulcus (ms) and lateral sulcus (ls) conspicuous, very deep. Postfemur (pof) conspicuous, ventrally narrow and short. Solenophore (sph) well-developed: lamina lateralis (ll) conspicuous, apically crest-like, quite thin; anterolaterally with a wide and conspicuous furrow: lamina medialis (lm) well-developed; process (plm) very short; distal lobe (dlm) very long and broad, indentation between distal lobe (dlm) and broad lobe (blm) inconspicuous; broad lobe (blm) moderately thick. Solenomere (sl) long.
Distribution and habitat.
This species is known only from a narrow distribution range in Phanom district. We consider D. corythosaurus sp. n. to be endemic for Surat Thani Province, Thailand.
The shape of the sternal lobe between male coxae 4 is variable: the tip is emarginate in the populations from Wat Tham Wararam and Tham Nam Lod, whereas specimens from the type locality have a truncate tip. The new species shares a similar shape of gonopodal solenophore with D. terae .
This species is almost impossible to find at first glance. We collected all specimens that were found on the humid rock walls by using flashlight. It blended in perfectly with the brown or black rock, this way probably avoiding being detected by predators.
Desmoxytes cervina (brown morph) at Ban Song Phi Nong, was collected from rock walls, same habitat as the new species.
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