Monographis thatsonensis Huynh 2022, new species
Creators: name: Huynh, Cuong
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Polyxenida
Polyxenidae
Monographis
Monographis thatsonensis

description: Monographis thatsonensis new species
Figures 2, 18–23
Material examined: Holotype, adult male (IEBR-Myr 993) and paratypes: Adult, two males (IEBR-Myr 994) two females (IEBR-Myr 995) and subadults, three females with 12 pairs of legs (IEBR-Myr 996) were collected from Cam Mountain, 10.496944N, 104.981389E; elevation 662 m, in the Seven Mountain Ranges (That Son), located in Tri Ton and Tinh Bien districts, An Giang Province, Vietnam. All types were deposited in the Institute of Ecology and Biological Resources, Vietnam. Specimens were collected by author CH on 8 th July 2017.
Diagnosis: Body length 2.0–3.0 mm. Antennal article VI with 15–16 bacilliform sensilla forming crescent shape, setiform sensillum located in anterior position, conical sensillum present near centre of crescent. Labrum asetose, long slender anterior setae on anterior margin. Telotarsus with anterior and posterior lateral processes equal in length and shorter than half-length of claw, lamella processes present, anterior setiform process longer than claw.
Description:
Holotype male body 2.0 mm; paratypes: males 2.0– 2.2 mm, females 2.4–3.0 mm; caudal bundle 0.5 mm, nest trichomes 0.2 mm.
Head: Arrangement of post vertex trichomes as for Monographis cattienensis with the holotype having 12 sockets on both sides in anterior rows, posterior rows with 4 sockets (L) and 3 sockets (R) (Figures 18A & 18B, 22A). Paratype showed anterior rows with 12–16 sockets, posterior rows with 3–4, these setae shorter in length than labrum width (Paratype with 8–10 setae). Clypeo-labrum: Holotype, labrum surface asetose (l), labrum posterior margin has a row of minute backward-pointing setae (sb). Lateral lamella (Ll) and single broad lamella each side median cleft (mc), 12 (L) and 8 (R) slender setae (sa) present on anterior margin of labrum (Figures 18C & 22C & 22D).
Antennae: Antennal article VI with 15–16 bacilliform sensilla. Holotype with 15 bacilliform sensilla forming a crescent shape with 3 thick (T), 3 thin bacilliform sensilla (t), 3 medium-length thin bacilliform sensilla (tm), and 6 short thin bacilliform sensilla (ts), setiform sensillum (S) located in anterior position, conical sensillum (C) present near centre of crescent (Figures 19C, 21B & 21D).
Telotarsus: Claw slender, anterior (a) and posterior lateral (p) processes equal in length and shorter than halflength of claw (c), lamella processes (la) present, anterior setiform process (s) longer than claw (Figures 20B & 23D).
Telson: Arrangement of dorsal ornamental trichome sockets similar to M. cattienensis with 14 trichome sockets a left side and 15 sockets on right side of the telson in the holotype (paratype with 14–18 sockets). (Figures 20C, 23A & 23B).
Remarks: Monographis thatsonensis sp. n. showed a distinctive pattern of sensilla on antennal article VI, labrum structures, anterior and posterior lateral processes equal in length and shorter than half-length of claw, anterior setiform process longer than claw.
Etymology: Monographis thatsonensis is named after the Seven Mountain Ranges, derived from Sino-Vietnamese, meaning: That Son, in An Giang Province, Vietnam.
description: Published as part of Huynh, Cuong, 2022, Four new species of Monographis Attems, 1907 (Diplopoda, Polyxenida, Polyxenidae) from Vietnam, pp. 393-420 in Zootaxa 5214 (3) on pages 411-413, DOI: 10.11646/zootaxa.5214.3.4, http://zenodo.org/record/7389267