Eusarcus marmoreus, Júnior & Ázara & Ferreira, 2021

Júnior, Gilson Argolo dos Santos, Ázara, Ludson Neves de & Ferreira, Rodrigo Lopes, 2021, Three new species of Eusarcus Perty, 1833 (Opiliones, Gonyleptidae) from Brazilian caves, European Journal of Taxonomy 740 (1), pp. 36-54: 43-47

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Eusarcus marmoreus

sp. nov.

Eusarcus marmoreus   sp. nov.

Figs 4–6 View Fig View Fig View Fig , 10–11 View Fig View Fig


Eusarcus marmoreus   sp. nov. can be distinguished from all species of the genus by having coxa IV with one transversal, proapical, trifurcated and truncated apophysis, with one dorsal apex higher than the other two ventrally-disposed apices. Eusarcus marmoreus   sp. nov. resembles E. berlae (Mello-Leitão, 1932)   , E. sergipanus Hara   & Pinto-da-Rocha, 2010, E. signatus (Roewer, 1949)   and E. sooretamae (Soares & Soares, 1946)   by the presence of a proapical truncated apophysis at coxa IV but can be distinguished by the following characters: unarmed scutal area III, low ocularium with a median spine, femur IV with proventral and retroventral rows of acuminate tubercles increasing in size apically and trochanter IV with only one high (taller than trochanter width) promedian apophysis.


The specific epithet ʻ marmoreus   ʼ means ʻof marbleʼ in Latin and refers to the lithology of the cave where the type specimen was found.

Material examined

Holotype BRAZIL • ♂; Espírito Santo State, Vargem Alta MUnicipality, Caverna Archimides Panssini cave ; 20°41′15.3″ S, 41°03′45.0″ W; 4 Apr. 2014; R.L. Ferreira et al. leg.; ISLA 12968 (destroyed). GoogleMaps  

Paratypes BRAZIL • 3 ♀♀; same collection data as for holotype; ISLA 66190 to 66192 GoogleMaps   1 ♂; same collection data as for holotype; ISLA 1472 (destroyed) GoogleMaps   .


Male (holotype, ISLA 12968)

MEASUREMENTS. DSL 4.79, DSW 3.41, femur I 2.72, II 6.27, III 4.08, IV 5.03.

DORSUM ( Fig. 4A, E View Fig ). Blunt PAM; acuminate median paracheliceral projection lower than PAM. Low ocularium with median spine (about two times ocularium height). Carapace with scattered granules. Scutal areas I–IV with scattered granules with higher density on scutal areas III–IV. Posterior margin of dorsal scUtUm with scattered granUles. Free tergites I–III with a defined row of granUles. Anal opercUlUm with scattered granules.

VENTER ( Fig. 4B View Fig ). Coxa I with irregular row of setiferous tubercles, coxae II–IV densely and irregularly granulate.

CHELICERAE. Segment I with two ectal-basal tubercles fused at the base and one irregular mesal-basal tubercle.

PEDIPALPS. Trochanter with sparse tubercles dorsally. Femur with one mesal apical setiferous tubercle.

LEGS ( Fig. 5 View Fig ). Coxae I–III with scattered granules; coxa IV with one transversal, proapical, trifurcated and truncated apophysis, with one dorsal apex higher than the other two ventrally-disposed apices. Trochanters I–IV with scattered tubercles; trochanter IV with one high (taller than trochanter width) promedian apophysis, which is conical, with rounded and anteriorly-curved apex. Femur III with proventral and retroventral rows of acute tubercles increasing in size apically; femur IV slightly sinuous, with small PDS and RDS, with proventral and retroventral rows of acuminate tubercles increasing in size apically. Patellae, tibiae and metatarsi I–IV granUlated withoUt defined armatUre.

COLOURATION (in alcohol) ( Figs 4–5 View Fig View Fig ). Body and appendages background colour Strong Brown (55), appendages Strong Orange (50).

PENIS ( Fig. 6 View Fig ). Ventral plate dorsally concave with substraight lateral margins; distal margin straight; ventral surface entirely covered with type T1 microsetae; with three pairs of lateral-distal MS C1–C3, three wide pairs of A1, one pair of B1, one pair of minute D1, and E1 absent. Stylus smooth, wider at apex, ventrally tilted. Ventral process spatula-shaped, dorsally tilted.

Female (paratype, ISLA 66190)

MEASUREMENTS. DSL 4.73, DSW 2.93, femur I 2.40, II 5.18, III 3.57, IV 4.53.

Similar to male, except for leg IV unarmed with only coxa IV having one short proapical tubercle.

Intraspecific variation

Males (n = 2): DSL 4.79–4.17; DSW 3.41–3.02, femur I 2.72–2.44, II 6.27–6.11, III 4.08–4.20, IV 5.03– 5.12.

Geographical distribution

Known only from the type locality ( Fig. 11 View Fig ).

Ecological remarks

Archimides Panssini is a marble cave located in Vargem Alta Municipality (Espírito Santo State, southreastern Brazil). It possesses around 150 meters of horizontal projection, with an irregular topography. The inner cave chamber harboUrs a small amoUnt of water flow. ThUs, organic resoUrces observed in the cave were vegetal debris broUght in by water flow and piles of bat gUano, especially those produced by hematophagous bats. Roots from the external vegetation were also observed in a few areas. Specimens of Eusarcus marmoreus   sp. nov. were found freely walking in the inner cave chambers, usually associated with moistened substrates ( Fig. 10B View Fig ). The Archimides Panssini Cave is also the type locality of the troglobitic palpigrade Eukoenenia spelunca Souza & Ferreira, 2011   ( Souza & Ferreira 2011), which reinforces its relevance. The cave is located in the Atlantic Forest domain, and the external landscape is topographically heterogeneous. The region presents a Cwa climate according to the Köppen classification system, with an average annUal precipitation ranging from 1000 to 1300 mm and an average annual temperature of 20.9ºC. The external landscape is quite altered, especially due to the removal of native vegetation for crops. Furthermore, many quarries for the extraction of marble were observed in the area during the last visit (in 2014) ( Fig. 10A View Fig ), which represents a serious threat for species associated with caves.