Rotundotergum elevatum Golovatch, Bouzan & Gallo, 2022

Golovatch, Sergei I., Bouzan, Rodrigo S., Gallo, Jéssica S. & Bichuette, Maria E., 2022, A new genus and two new species of the millipede family Chelodesmidae from Bahia state, northeastern Brazil, including a likely troglobiont (Diplopoda, Polydesmida), Zootaxa 5155 (1), pp. 87-104 : 98-101

publication ID

https://doi.org/ 10.11646/zootaxa.5155.1.4

publication LSID

lsid:zoobank.org:pub:6E9C5E63-48B6-4D29-B98D-3DA2755A5AB8

DOI

https://doi.org/10.5281/zenodo.6669356

persistent identifier

https://treatment.plazi.org/id/03AA0A59-BB4A-F170-FF48-7677FAECF822

treatment provided by

Plazi

scientific name

Rotundotergum elevatum Golovatch, Bouzan & Gallo
status

sp. nov.

Rotundotergum elevatum Golovatch, Bouzan & Gallo , sp. nov.

Figs 8–10 View FIGURE 8 View FIGURE 9 View FIGURE 10

Material examined. Holotype male ( LES0027945 View Materials ), Brazil, Bahia State, São Desidério Municipality, Gruta Sumidouro do João Baio cave , S12°22’27.6”, W44°53’31.7”, ca 580 m a.s.l., 2.XI.2011, M.E. Bichuette, J.E. Gallão, C.S. Fernandes & D. R. Pedroso leg. GoogleMaps

Paratypes: 1 male, 2 subadult females ( LES0027946 View Materials ), same place, taken together with holotype .

Name. To emphasize the mostly upturned paraterga, neuter adjective in genitive case.

Diagnosis. Same as for the genus.

Description. Length of adults ca 35 mm (male holotype) or 39 mm (male paratype), width of midbody pro- and metazonae 3.0 and 4.7 mm (male holotype) or 3.1 and 5.0 mm (male paratype), respectively. Coloration mostly red-brown (male paratype), light reddish only mid-dorsally in anterior half of body (male holotype) or uniformly beige to light brown (subadult female paratypes), adults with lighter to yellowish antennae, legs, lateral calluses on paraterga, and tip of epiproct ( Figs 8 View FIGURE 8 , 9A, B View FIGURE 9 , & D).

Adult body with 20 rings (18p+1a+T) ( Fig. 8 View FIGURE 8 ). Tegument mainly poorly shining, texture mostly leathery to finely striolate. Head poorly setose over clypeolabral region, vertex bare, epicranial suture evident ( Fig. 9C View FIGURE 9 ); isthmus between antennae about as wide as diameter of antennal socket ( Fig. 8C View FIGURE 8 ). Antennae relatively long and slender, poorly clavate due to only a slightly enlarged antennomere 6, in situ projecting past ring 3 dorsally (male) or 2 (subadult female); in length, antennomeres 2 = 5 = 6> 3 = 4> 1> 7 ( Fig. 8 View FIGURE 8 ). Genae subquadrate laterally ( Fig. 8 View FIGURE 8 ), incisura lateralis small and round, located beneath antenna ( Fig. 9C, T View FIGURE 9 ); gnathochilarium without peculiarities, very densely pilose.

In width, head <ring 5=16 <collum <2=3=4 (male), body gradually tapering towards telson on rings 16–19 ( Fig. 8 View FIGURE 8 ). Dorsum mostly slightly convex, generally smooth, metaterga largely very delicately striolate and rather densely microtuberculate, only caudal row of microtuberculations in front of rear tergal margin being regular ( Fig. 8 View FIGURE 8 ). Surface below paraterga more clearly striolate. Paraterga very strongly developed, mostly clearly upturned and reaching the level of dorsum, smaller, lower and subhorizontal in subadult females, in adult males set high, mostly at about upper ¼ height of metazonae ( Figs 8 View FIGURE 8 & 9D View FIGURE 9 ), collum crescent-shaped, regularly convex at a narrowly rimmed anterior margin, slightly concave in the middle at a faintly rimmed caudal margin; following metaterga shoulder-shaped at a clearly rimmed anterior margin, metaterga 2–5 each with a very small and sharp denticle drawn laterally at a clearly angular anterolateral corner, metaterga 2–4 each with a very flat and broad lateral callus; following metaterga smooth at lateral margin, each with similarly and clearly rounded lateral margins and both more narrowly rounded anterolateral and caudolateral corners, calluses being particularly thick and prominent on pore-bearing rings, and interrupted anteriorly by a small incision behind anterolateral corner; caudal margins of paraterga narrowly rimmed much like anterior margin ( Figs 8 View FIGURE 8 & 9B–D View FIGURE 9 ). Caudal corners of paraterga almost sharp, beak-shaped and distinctly drawn past rear tergal margin only in rings 17–19 ( Fig. 8 View FIGURE 8 ). Pore formula normal (5, 7, 9, 10, 12, 13, 15–19); ozopores small, located inside ovoid pits considerably before caudal corners of paraterga ( Figs 8 View FIGURE 8 & 9D View FIGURE 9 ). Tergal setae absent, no setation pattern traceable on metaterga. A weak transverse impression traceable on most metaterga. Stricture between pro- and metazonae distinct, but rather narrow, shallow and smooth (male). Limbus conspicuously brush-like ( Fig. 9B View FIGURE 9 ). Pleurosternal carinae increasingly low, arcuate, longitudinal ridges or bulges traceable from ring 2 until ring 6 (male). A poor axial line sometimes traceable on metaterga of adults ( Fig. 8 View FIGURE 8 ). Epiproct rather long, conical, slightly curved caudally, tip rounded; pre-apical papillae very small ( Fig. 8 View FIGURE 8 ). Hypoproct subtriangular, sharpened at tip; setigerous papillae at caudal corners very small and well separated; sides faintly convex ( Fig. 8C View FIGURE 8 ).

Sterna broad, without notable modifications even before ring 7, nearly glabrous, cross-impressions weak ( Fig. 8C View FIGURE 8 ). Legs long and slender ( Fig. 8 View FIGURE 8 ), 1.6–1.7 times as long as mid-body height, considerably shorter in subadult females; male legs without tibial chelae; in length, femur >> tarsus> tibia> prefemur = postfemur> coxa; claw short and simple ( Fig. 8 View FIGURE 8 ). Male gonopores located on distinct, distomesal, coniform gonapophyses ( Fig. 8C View FIGURE 8 ).

Gonopodal aperture subcordiform, much broader than following sterna, depressed caudal shelf with a few small and transverse crests ( Fig. 9B View FIGURE 9 ). Gonopods ( Figs 9C, D View FIGURE 9 & 10 View FIGURE 10 ) stout and mostly robust, with evident sternal rudiments (st) between gonocoxae (Cx); gonocoxa devoid of a distodorsal apophysis, but supplied with a distinct and setose distolateral lobe (lo) subtending the telopodite (Te); cannula (c) as usual, a thin curved tube, devoid of setae mesally at its base; prefemoral region (Pf) as usual, short, about half as long as an untwisted acropodite (A); caudal prefemoral process (PfP) long, slender, unciform, directed unusually strongly mesad and completely separated from A ( Fig. 10 View FIGURE 10 ); A laminar and membranous, suberect; seminal groove (Sg) running entirely on mesal side of Te, ending up on a spiniform solenomere (sl) branching off at A midway opposite a similarly slender and rounded acropodital process (AP), both sl and AP being equal in length ( Figs 9D View FIGURE 9 & 10 View FIGURE 10 ).

Remarks. Based on most or much of the body being clearly pigmented, up to red-brown, superficially this species is certainly not more than troglophilic. This only emphasizes the general impression that Chelodesmidae , however diverse and important in the fauna of Brazil, cannot be regarded as typical elements of cave biota.

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Departamento de Geologia, Universidad de Chile

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