Gigantomorpha sayapensis Ng & Srisonchai & Golovatch & Sutcharit & Panha & Latim & Likhitrakarn 2025, sp. nov.
Creators: name: Ng, Ting Hui
name: Srisonchai, Ruttapon
name: Golovatch, Sergei I.
name: Sutcharit, Chirasak
name: Panha, Somsak
name: Latim, Martinah
name: Likhitrakarn, Natdanai
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Polydesmida
Paradoxosomatidae
Gigantomorpha
Gigantomorpha sayapensis

description: Gigantomorpha sayapensis Ng & Likhitrakarn sp. nov.
urn:lsid:zoobank.org:act: 1B7E2FB6-3395-4DEA-B2C0-B33CB42E53DD
Figs 8–10
Diagnosis
Differs from all known congeners by the gonopod tip with a small bifid structure, lacking the distinct branching observed in other species. This characteristic appears to be particularly similar to both G. mutilata and G. transmontana. However, the new species differs in having a thicker, apically expanding solenophore (i.e., the solenophore becomes slightly wider towards the apex) (Figs 9B–C, 10A–C) (vs long, slender and tapering in all the other species).
Etymology
To emphasise the type locality, adjective in feminine gender.
Material examined
Holotype
MALAYSIA • ♂; Borneo, Sabah, Kota Belud, Kinabalu Park, Sayap Substation; 6°09′8.9″ N, 116°34′8.5″ E; ca 1071 m a.s.l.; 10 Mar. 2023; T.H. Ng, F. Anthony and D. Bantason leg.; SP 14835.
Description
Length of holotype 35.3 mm, width of midbody pro- and metazona of holotype, 2.5 and 5.1 mm, respectively.
Colouration of living animal castaneous brown (Fig. 8A); with contrasting pale pinkish paraterga, antennae dark brown, venter and legs yellowish brown; colouration of alcohol material after seven months of preservation a little faded to red-brown castaneous; paraterga pale pinkish to pale red, antennae brown to light brown, venter and legs light brown to light yellowish (Fig. 8B–J).
Clypeolabral region and vertex sparsely setose, epicranial suture distinct.Antennae rather short (Fig. 8A– C), reaching body ring 4 when stretched dorsally. In length, antennomere 3>2= 4>5>6>> 1=7. Interantennal isthmus ca 0.6 times diameter of antennal socket (Fig. 8B). In width, head <ring 3<4<collum <ring 2<5<6<7–16 (Fig. 8B), thereafter body gently and gradually tapering. Collum with three transverse rows of strong setae: 3+3 anterior, 2+2 intermediate, and 4+4 posterior; caudal corner very broadly rounded, paraterga declined ventrad, not produced past rear tergal margin (Fig. 8C).
Tegument rather smooth and shining, prozona delicately shagreened, metaterga smooth and leathery, posterior halves faintly rugulose, surface below paraterga microgranulate (Fig. 8A–F, H). Postcollum metaterga each with two transverse rows of setae: 2+ 2 in anterior and 3+ 3 in posterior row, setae in posterior row mostly abraded and borne on minute knobs or oblong wrinkles (Fig. 8B–F, H). Tergal setae rather short, strong, slender, about 1/5 metatergal length. Axial line traceable both on pro- and metazona. Paraterga strongly developed (Fig. 8A–F, H), subhorizontal, slightly upturned posteriorly, always lying high, at upper 1/3 midbody height, but remaining below dorsum; anterior edge broadly rounded and narrowly bordered, fused to callus; caudal corner almost completely to fully pointed, always extending past rear tergal margin, bent posteriad on rings 18 and 19; posterior edge oblique (Fig. 8B, D, F); paraterga thin blunt blades in lateral view, a little thicker only on pore-bearing rings (Fig. 8E). Calluses on paraterga delimited by a sulcus only dorsally, but on pore-bearing ring paraterga demarcated by sulci both dorsally and ventrally. Paraterga 2 broad, lateral edge with two small incisions at lateral edge (Fig. 8B), one in anterior 1/3, the other at posterior 1/3. Paraterga 3 and 4 each with an evident incision in anterior 1/3 and a small knob in posterior 1/3 (Fig. 8B). Lateral edge of paraterga of following rings with two small incisions, one in anterior 1/3, the other at midway, caudal incision in the pore-bearing rings smaller or gradually reduced in posterior rings (Fig. 8D, F). Ozopores evident, lateral, each lying in an ovoid groove at about 1/3 metatergal length in front of posterior edge of metaterga (Fig. 8C, E, H).
Transverse metatergal sulci usually distinct (Fig. 8B, D, F), slightly incomplete on rings 4 and 19, complete and clearly visible on metaterga 5–18, rather deep and wide, reaching the bases of paraterga, arcuate, faintly beaded at bottom. Stricture between pro- and metazona narrow, deep, beaded at bottom down to base of paraterga (Fig. 8C–E). Pleurosternal carinae complete crests on ring 2, thereafter broken into an anterior bulge and a caudal tooth, both increasingly reduced until ring 7, thereafter missing (Fig. 8C, E, H).
Epiproct (Fig. 8F–H) conical, flattened dorsoventrally, subtruncate, with two evident apical papillae directed caudally, both pointed at tip; pre-apical papillae small, but evident, lying close to tip. Hypoproct subtrapeziform (Fig. 8G), small setigerous knobs at caudal edge well-separated and evident.
Sterna sparsely setose, without modifications (Fig. 8G); cross-impressions shallow; a sparsely setose and transverse lobe bearing a paramedian pair of evident, basally contiguous cones between male coxae 4 and a pair of small, separated cones near each coxa 5 (Fig. 8I–J). A paramedian pair of small, but evident tubercles in front of gonopod aperture. Legs long and slender, midbody legs ca 1.3–1.5 times as long as body height (Fig. 8A, C); prefemora without modifications; tarsal brushes present until legs of ring 18.
Gonopods (Figs 9–10) rather simple; coxa long and thick, subcylindrical, a little curved caudad, sparsely setose distoventrally (Figs 9A–B, 10A–C). Prefemoral part short, densely setose as usual, about 1/4 as long as femoral part + postfemoral part (Fig. 10A–C). Femoral part long and slender, expanded distad, slightly curved, postfemoral part demarcated by an oblique lateral sulcus (Figs 9B–C, F, 10A, C); seminal groove running entirely mesally along the femoral part, solenomere (sl) flagelliform, fully sheathed by solenophore (sph). Lamina medialis (lm) well developed, prominent and unciform, terminal tip clearly bifid, terminal lobe a little larger than subterminal one (Figs 9A–D, E, 10B–C). Lamina lateralis (ll) unciform, shorter than lamina medialis (lm), bifid, with two subequal lobes (Figs 9, 10B–C).
Remarks
This species was collected from the ground, under a rotten branch, in a lower montane forest habitat on the western side of the Kinabalu Park complex (Fig. 1C).
description: Published as part of Ng, Ting Hui, Srisonchai, Ruttapon, Golovatch, Sergei I., Sutcharit, Chirasak, Panha, Somsak, Latim, Martinah & Likhitrakarn, Natdanai, 2025, A taxonomic study of millipede genera, Orangutana Golovatch, 1996 and Gigantomorpha Jeekel, 1963 (Diplopoda, Polydesmida, Paradoxosomatidae), with description of four new species from Sabah, Borneo, East Malaysia, pp. 221-248 in European Journal of Taxonomy 987 on pages 235-238, DOI: 10.5852/ejt.2025.987.2871, http://zenodo.org/record/15275702