Gigantomorpha alabensis 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 alabensis

description: Gigantomorpha alabensis Ng & Likhitrakarn sp. nov.
urn:lsid:zoobank.org:act: 6EEF956F-4240-4B6F-9213-B9B91A3A5A5B
Figs 2–4
Diagnosis
This new species closely resembles G. sayapensis sp. nov., but differs in the pleurosternal carinae in males present until ring 7 (vs 4), shorter male legs, ca 1.3–1.5 times as long as midbody height (vs 1.5– 1.7 times), and tarsal brushes in males present until ring 18 (vs ring 16), coupled with the gonopodal lamina medialis (lm) tip bifid, with a deep and evident incision (vs a single subtruncate tip).
Etymology
To emphasise the type locality, adjective in feminine gender.
Material examined
Holotype
MALAYSIA • ♂; Borneo, Sabah, Tambunan, Crocker Range Park, Gunung Alab Substation; 5°49′17.6″ N, 116°20′29.4″ E; ca 1904 m a.s.l.; 19 Mar. 2023; T.H. Ng, T.S. Liew and F. Anthony leg.; SP 14836.
Description
Length of holotype 28.5 mm, width of midbody pro- and metazona of holotype, 2.2 and 4.8 mm, respectively.
Colouration of alcohol material after seven months of preservation castaneous with a pattern of contrasting pale pinkish to whitish paraterga and epiproct, antennae brown to light yellowish, venter brownish to light brown, and legs light brown to light yellowish (Fig. 2A–I).
Clypeolabral region and vertex densely setose, epicranial suture distinct.Antennae rather short (Fig. 2B), reaching body ring 4 when stretched dorsally. In width, head <ring 3<collum <ring 4<2<5<6 <7–16 (Fig. 2A), 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. 2A–B).
Tegument rather smooth and shining, prozona delicately shagreened, metaterga smooth and leathery, posterior halves faintly rugulose, surface below paraterga microgranulate (Fig. 2A–F). Postcollum metaterga each with two transverse rows of setae: 2+ 2 in anterior, 3(4)+3(4) in posterior row, setae in posterior row mostly abraded and borne on minute knobs or oblong wrinkles. Tergal setae rather short, strong, slender, about 1/4 metatergal length. Axial line traceable both on pro- and metazona. Paraterga strongly developed (Fig. 2A–G), subhorizontal, slightly upturned posteriorly, always lying high, at upper 1/3 midbody height, but remaining below dorsum; anterior edge on rings 2–4 each broadly rounded and narrowly bordered, fused to callus; following rings slightly rounded and oblique laterally (Fig. 2A); caudal corner almost completely to fully pointed, always extending past rear tergal margin, bent posteriad on rings 16–19 (Fig. 2E–G); posterior edge oblique (Fig. 2A, C, F); paraterga thin blunt blades in lateral view, a little thicker only on pore-bearing rings (Fig. 2D). Calluses on paraterga delimited by a sulcus only dorsally, but on pore-bearing ring paraterga with sulci both dorsally and ventrally. Paraterga 2–4 broad, lateral edge of each with two small incisions at lateral edge (Fig. 2A), one in anterior 1/3, the other in posterior 1/3. Lateral edge of paraterga of following rings with two small incisions, one larger and one smaller, but evident incisions in anterior 1/3 (Fig. 2A, C, F). Ozopores evident, lateral, lying in an ovoid groove at about 1/3 of metatergal length in front of posterior edge of metaterga (Fig. 2B, D–E).
Transverse metatergal sulci usually distinct (Fig. 2A, C, F), slightly incomplete on ring 19, complete and clearly visible on metaterga 5–18, deep and narrow, reaching the bases of paraterga, line-shape, ribbed at bottom. Stricture between pro- and metazona narrow, deep, beaded at bottom down to base of paraterga (Fig. 2A, C, F). Pleurosternal carinae complete crests bulged anteriorly and with a sharp caudal tooth on ring 2, thereafter only a sharp caudal tooth on ring 3, a small denticle on ring 4, thereafter missing (Fig. 2B).
Epiproct (Fig. 2E–G) conical, flattened dorsoventrally, subtruncate, with two evident apical papillae directed caudally, both pointed; pre-apical papillae small, but evident, lying close to tip. Hypoproct subtrapeziform (Fig. 2G), small setigerous knobs at caudal edge well-separated and evident.
Sterna separsely setose, without modifications; cross-impressions rather shallow; a sparsely setose, 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. 2H–I). A paramedian pair of small, but evident tubercles in front of gonopod aperture. Legs long and slender, midbody ones ca 1.5–1.7 times as long as body height; prefemora without modifications; tarsal brushes present until legs of ring 16.
Gonopods (Figs 3–4) simple; coxa long and thick, subcylindrical, a little curved caudad, sparsely setose distoventrally (Figs 3A–B, E, 4A–B). Prefemoral part short, densely setose as usual, about 1/4 as long as femoral part + postfemoral part (Fig. 3A–B). Femoral part long and slender, expanded distad, slightly curved, postfemoral part demarcated by an oblique lateral sulcus (Figs 3A–D, F, 4A–B); seminal groove running entirely mesally along the femoral part, solenomere (sl) flagelliform, fully sheathed by solenophore (sph). Lamina medialis (lm) well developed, elevated, prominent, stout, slightly expanded apically, tip bifid with a deep and evident incision (Figs 3A–D, 4A), terminal lobe with minute denticles at ventral margin (Fig. 3A, C, F). Lamina lateralis (ll) shorter than lamina medialis (lm), subtruncate at tip (Figs 3A, C, 4B).
Remarks
This species was found at the Gunung Alab Substation (Fig. 1C), inside a small building which houses the office and guesthouse, adjacent to forest trails, and together with Orangutana koropungoi Ng & Likhitrakarn sp. nov.
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 225-228, DOI: 10.5852/ejt.2025.987.2871, http://zenodo.org/record/15275702