Rhysida sada, Joshi & Karanth & Edgecombe, 2020

RHYSIDA SADA SP. NOV.

( FIG. 14)

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Diagnosis: Twenty antennal articles. Coxosternal tooth-plates with 4 + 4 to 5 + 5 teeth. Paramedian sutures <5% length of sternites. Coxopleural process with two apical spines and one dorsal spine. Ultimate leg prefemoral spine formula VL2, VM1, DM1.

Type material

Holotype: CES091360 , Gunyacha Maal , Phansad Wildlife Sanctuary, Raigad district, Maharashtra, India (18.4152°N, 72.9712°E, 200 m a.s.l.), collected by Jahnavi Joshi, 16 September 2009. GoogleMaps

Paratypes: CES091350 , Guptbhima, Bhimashankar Wildlife Sanctuary, Pune district , Maharashtra ; CES091361 , Gunyacha Maal, Phansad Wildlife Sanctuary, Raigad district , Maharashtra . Morphology only: CES091359 , Kondhavala, Bhimashankar Wildlife Sanctuary, Pune district , Maharashtra, India . Locality coordinates in the Supporting Information ( Table S1).

Etymology: This species is found on lateritic plateaus in the northern Western Ghats, which are called ‘ sada ’ in Marathi, one of the predominant languages spoken in the region. It is a noun in apposition.

Description: Length ≤ 40 mm. Twenty antennal articles, basal three articles glabrous dorsally and ventrally ( Fig. 14A). Cephalic plate and T1 smooth. Longitudinal median furrow on anterior 10% of cephalic plate. Cephalic plate and T1 light grey, the following tergites and legs grey with light green; ultimate legs dark grey. Forcipular coxosternal tooth-plates slightly wider than longer, with 4 + 4 main teeth, the outermost smaller than the inner two; innermost tooth variably with a distinct cusp (5 + 4 or 5 + 5); base of tooth-plates defined by oblique sutures diverging at 120° ( Fig. 14B). Trochanteroprefemoral process bearing two apical teeth and one lateral tooth. Tergites with paramedian sutures complete from T5. Tergites not marginated except tergite of ultimate leg-bearing segment. Tergites with longitudinal depressions ( Fig. 14G). Paramedian sutures 5% length of sternites or indistinct ( Fig. 14F). Tergite of ultimate leg-bearing segment as wide as long, convex, with parallel lateral margins, rounded posteromedially ( Fig. 14H). Sternite of ultimate leg-bearing segment wider than long, with two sutures/depressions on both sides ( Fig. 14D). Coxopleuron moderately long, 1.5 times the length of sternite of ultimate leg-bearing segment; coxopleural process with two apical spines and a dorsal spine; pores dense, with pore-field terminating distinctly beneath dorsal margin of coxopleuron; non-porose area on coxopleural process a narrow, short strip towards the tip ( Fig. 14C, D). Ultimate legs long ( Fig. 14E, H), with prefemur ≤ 4.5 mm, femur ≤ 4 mm, tibia ≤ 3.5 mm, tarsus 1 ≤ 2 mm and tarsus 2 ≤ 1.5 mm; prefemur with large spines, as follows: VL2, VM1, DM1 ( Fig. 14E, H). Legs 1–17 (one individual with 14) with two tarsal spurs, legs 18–19 with one; leg 20 lacking tarsal spur. Legs 1–2 with one tibial spur. Leg 1 with femoral spur.

Distribution: This species is endemic to lateritic plateaus of the northern Western Ghats (also called as ferricretes; Thorpe & Watve, 2015), one of the unique and threatened habitats in the Western Ghats. This is home to many endemic species, with relatively narrow distributions (snakes, lizards, plants and caecilians; Thorpe & Watve, 2015). This species is currently known from two distinct localities: Bhimashankar Wildlife Sanctuary at the northern edge of the Western Ghats and Phansad Wildlife Sanctuary, on the west coast, relatively isolated lowland forests from the main mountain range of the Western Ghats.

Remarks: Phylogenetically, this species is part of a clade composed of R. lewisi , R. immarginata , R. sp 1 and R. sp. 2, but its position in that clade is not resolved. It is retrieved as a single putative species by GMYC and mPTP ( Fig. 3). It is diagnosibly distinct from all of these allied species in having negligible development of paramedian sutures on the sternites, a unique combination of the number of antennal articles (fixed at 20) and the numbers and arrangements of coxopleural and prefemoral spines.