Tylopus dorsalis, Likhitrakarn & Golovatch & Panha, 2016

Likhitrakarn, Natdanai, Golovatch, Sergei I. & Panha, Somsak, 2016, The millipede genus Tylopus Jeekel, 1968 (Diplopoda, Polydesmida, Paradoxosomatidae), with a key and descriptions of eight new species from Indochina, European Journal of Taxonomy 195, pp. 1-47 : 22-25

publication ID	https://doi.org/ 10.5852/ejt.2016.195
DOI	https://doi.org/10.5281/zenodo.3852408
persistent identifier	https://treatment.plazi.org/id/03EB5A00-FFEA-7D70-ACE4-D63EFE689B9C
treatment provided by	Valdenar
scientific name	Tylopus dorsalis
status	sp. nov.

Treatment

Tylopus dorsalis View in CoL sp. nov.

urn:lsid:zoobank.org:act:EDC8D353-BE43-4D79-8BA4-E23D0FD57CE7

Figs 16 – 17 View Fig View Fig , 26 View Fig

Diagnosis

The live coloration is similar to that of T. trigonum , but the new species differs in the head and collum being light brown (versus blackish), and the pattern not contrasting (versus contrasting); the gonopod structure is similar to that of T. crassipes Golovatch, 1984 , but the new species differs in process x being longer and its tip rounded dorsally.

Etymology

To emphasize process x on the solenophore arising dorsally; adjective.

Material examined

Holotype

LAOS: Ƌ, Phuthalang forest protected area, Boun Neua , Phongsali, 21°37'30" N, 101°55'55" E, ca 1125 m a.s.l., 16 Oct. 2014, leg. C. Sutcharit & R. Srisonchai ( CUMZ).

GoogleMaps

Paratype

LAOS: 1 ♀, same data as for holotype ( CUMZ).

Description

MEASUREMENTS AND COLOUR. Length 22.1 (Ƌ) or 22.3 mm (♀), width of midbody pro- and metazonae 2.5 and 3.6 mm (Ƌ) or 1.97 and 2.55 mm (♀), respectively. Live coloration light brown ( Fig. 16A View Fig ); paraterga, legs and epiproct light yellow-brown, head and collum light brown, antennomere 7 blackish, collum and following terga each with a light brown triangle and a dark brown collar covering both pro- and metazonae. Coloration of alcohol material faded after one year of preservation to light brown, with a pattern of a dark brown band in pre-sulcus area on metazonae and a pair of paramedian, longitudinal, brown stripes dorsally both on pro- and metaterga; paraterga light red-brown, head brown, antennae, legs, venter and epiproct light yellow-brown ( Fig. 16 View Fig B–J).

HEAD. Clypeolabral region densely, vertex sparsely, setose; epicranial suture distinct. Antennae rather short ( Fig. 16A View Fig ), extending behind body segment 3 (Ƌ) or 2 (♀) when stretched dorsally. In width, head <segment 3 <2 = 4 <collum <segments 5–17 (Ƌ, ♀); thereafter body gently and gradually tapering. Collum with three transverse rows of setae: 3+3 anterior, 1+1 intermediate and 2+2 posterior; a small lateral denticle at about anterior 1/3 ( Fig. 16B, D View Fig ); caudal corner of paraterga very broadly rounded, declined ventrad, not surpassing rear tergal margin.

BODY. Tegument smooth and shining, prozonae finely shagreened, metaterga smooth and leathery, posterior halves rugulose, surface below paraterga microgranulate ( Fig. 16 View Fig B–F, H). Postcollum metaterga with two transverse rows of setae: 2+ 2 in anterior (pre-sulcus) row, also 2+ 2 in posterior (post-sulcus) one. Tergal setae long, strong, slender, about 2/3 of metatergal length.Axial line traceable both on pro- and metazonae. Paraterga well-developed ( Fig. 16B, D, F View Fig ), especially so in Ƌ, set rather high (at upper 1/3 of body height), anterior edge rounded and narrowly bordered, fused to callus; caudal corner very narrowly rounded, extending increasingly behind rear tergal margin, posterior edge slightly oblique. Calluses on paraterga delimited by a sulcus only dorsally. Paratega 2 broad, anterior edge angular, lateral edge with three evident incisions. Lateral edge of following paraterga with a clear incision in anterior 1/3 ( Fig. 16B, D View Fig ). Paraterga 14–19 with caudal corner extending increasingly behind, with tip evidently curved mesad ( Fig. 16F View Fig ). Ozopores distinct, lateral, lying in an ovoid groove at about 1/3 of metatergal length in front of posterior edge of metaterga. Transverse sulcus usually distinct ( Fig. 16B, D, F View Fig ), slightly incomplete on segment 3, complete on segments 4–18, narrow, line-shaped, deep, not reaching bases of paraterga, beaded at bottom. Stricture between pro- and metazona evident, wide, rather deep, clearly ribbed at bottom down to base of paraterga ( Fig. 16B, D – G View Fig ). Pleurosternal carinae complete crests with a sharp caudal tooth on segments 2–7, reduced and remaining only a sharp caudal tooth on segment 8, reduced to a small, delicately denticulate, caudal crest on segments 9–15, retained as a minute tooth on segment 16, thereafter missing (Ƌ), or with complete crests and a sharp caudal tooth on segments 2–4, remaining only an evident caudal tooth on segments 5–12, a rounded caudal crest on segments 13–17, thereafter missing (♀) ( Fig. 16C, E, H View Fig ). Epiproct ( Fig. 16 View Fig E–G) conical, flattened dorsoventrally, with two evident, rounded, apical papillae; tip subtruncate; lateral pre-apical papillae evident, lying close to tip. Hypoproct roundly subtriangular, setigerous knobs at caudal edge small and well-separated ( Fig. 16G View Fig ).

STERNA. Separsely setose, without modifications; cross-impressions shallow; an entire, linguiform, sternal lobe between Ƌ coxae 4 ( Fig. 16I – J View Fig ). Legs long and slender, midbody ones ca 1.3–1.4 (Ƌ) or 0.9–1.1 (♀) as long as body height; Ƌ femora 6 bulged and microtuberculate ventrally ( Fig. 17E View Fig ); Ƌ femora 7 also bulged ventrally ( Fig. 17F View Fig ), but following femora not swollen; legs of segments 7–16 each with femur, postfemur, tibia and tarsus carrying a small adenostyle (tubercle) medially ( Fig. 17G View Fig ), telopodites particularly densely setose ventrally ( Fig. 17G View Fig ), tarsal brushes present until Ƌ segment 6.

GONOPOD. Rather simple ( Fig. 17 View Fig A–D); coxa slightly curved caudad, sparsely setose distoventrally. Femorite slightly curved and stout, with an evident mesal groove and a clear distolateral sulcus demarcating a postfemoral part; process h rather high, directed anterodorsally, flattened, tip rounded; solenophore (sph) rather slender, strongly coiled, flattened and evidently bifid, with process x being slim and directed dorsally.

N	Nanjing University
E	Royal Botanic Garden Edinburgh
C	University of Copenhagen
R	Departamento de Geologia, Universidad de Chile
CUMZ	Cameroon University, Museum of Zoology