Betaburmesebuthus fleissneri Lourenço & Velten, 2016

(Figs 12–14)

Material. NIGP 200653, an adult male, part of right pedipalp missing.

Diagnosis (emended). This species can be clearly distinguished from other Betaburmesebuthus species by the following set of characters: 1) anterior margin of carapace with a single moderately marked median concavity (Figs 13A, 14A; Lourenço & Velten, 2016a: fig. 5); 2) spiracles oval to round (Lourenço & Velten, 2016a: fig. 6); 3) pectines with 19–21 teeth (Fig. 13B; Lourenço & Velten, 2016a); 4) vesicle pear-shaped and very long, and aculeus very long and strongly curved (Figs 13B, 14B); 5) dorsal patellar spur carina with four strong tubercles and femur with three to four internal strong tubercles (Fig. 14C, D; Lourenço & Velten, 2016a: fig. 2); 6) Chela manus with two small tubercles on internal surface (Lourenço & Velten, 2016a: fig. 10); 7) telotarsus covered by numerous ventrosubmedian setae (Fig. 14E– G, Lourenço & Velten, 2016a: fig. 8).

Description. Carapace. Covered by coarse granules; a pair of superciliary carinae well developed; median, posterior median and posterior furrows evident (Figs 13A, 14A); median eyes oval, large sized and separated by one ocular diameter (Fig. 14A); PDMi posterodorsal to PLMa, ADMi mixed with coarse granules, not clear (Fig. 14A).

Coxosternal region. Surface covered by impurity, not clear but obscure outline visible; genital operculum longitudinally divided, two valves rounded and full (Fig. 13B).

Chelicerae. With numerous setae on internal surface (Fig. 14A); cheliceral dentition not visible (Fig. 14A).

Pedipalps. Femur with five carinae (Figs 13E, 14D): internomedian carina well-marked with several strong tubercles; dorsointernal carina crenulate; dorsoexternal, ventroexternal and ventrointernal carinae costate. Patella with seven carinae (Figs 13E, 14C): Dorsal Patellar Spur carina (DPSc) and Ventral Patellar Spur carina (VPSc) well-developed; dorsointernal, dorsomedian and ventrointernal carinae costate with several granules; ventroexternal and dorsoexternal carinae smooth and costate. Chela very slender (Cl/Cw = 7.67, Table 1).

Trichobothrial pattern (Figs 13E, 14C, D). Femur with 7 trichobothria observed, 4 dorsal, 1 internal and 2 external trichobothria, trichobothrium e 1 proximal to trichobothrium d 5. Patella with 8 trichobothria observed, including 1 dorsal, 1internal and 6 external trichobothria. Chela fixed finger with 2 dorsal trichobothria observed.

Legs. Prolateral and retrolateral pedal spurs present on all legs (Fig. 14E–G). Ungues long and moderately curved, dactyl pointed (Fig. 14E–G).

Pectines (Fig. 13B). Lamellae not clear, peg sensillae very short and sensory area fully occupied distal end of teeth.

Mesosoma. Tergites covered by coarse granules (Figs 12A, 13A, D), median carina evident on posterior half of all tergites (Fig. 12A); dorsolateral carinae present on tergites IV–VI (Fig. 13D); tergite VII with five costate carinae (Fig. 13D): paired dorsolateral and lateral carinae, and one axial carina on anterior half. Sternites covered by impurity, not clear.

Metasoma (Fig. 13C, J). All segments longer than width and covered by macrosetae ventrally.Segments I–III with distinct depression dorsally; segments I and II with ten well marked carinae (paired ventromedian, ventrolateral, lateral, dorsolateral, and dorsal carinae); segments III and IV with eight well marked carinae (paired ventromedian, ventrolateral, dorsolateral, and dorsal carinae) and lateral carina reduced on segment III; segment V with five well marked carinae (single ventromedian carina, paired ventrolateral and dorsolateral carinae); dorsal carinae on segments I–IV obviously serrated.

Telson (Figs13C, 14B).Vesicle with a well-developed ventromedian carina, ventral surface covered by several macrosetae and subaculear setal pair significantly evident; one or two small subaculear tuberance present on terminal of ventromedian carina; base of aculeus moderately wide and shorter than half of vesicle; aculeus with several microsetae proximally and progressively darker towards distal.

Remarks. Lourenço & Velten (2016) regarded the serrated dorsal carinae of metasoma I–IV as a diagnostic character of Betaburmesebuthus fleissneri . However, we noticed that this character is shared by all members of Betaburmesebuthus and especially evident in mature individuals (Figs 13C, J, 24H, 29C). Our adult specimen provides more reliable features than the immature holotype.

We remeasured the ratio of chela length and width from figure 2 in Lourenço & Velten (2016) and found it is about 7.50 in holotype rather than 6.82 in the original paper, close to the value in our specimen (7.67) .