Betaburmesebuthus bellus Lourenco 2016
Creators: name: XUAN, QIANG
name: CAI, CHEN-YANG
name: HUANG, DI-YING
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Scorpiones
Palaeoburmesebuthidae
Betaburmesebuthus
Betaburmesebuthus bellus

description: Betaburmesebuthus bellus Lourenço, 2016
(Figs 1–7)
Material. NIGP 200648, one probable juvenile male, the part of right pedipalp finger and metasoma damaged. NIGP 200649, one probable juvenile female, a complete scorpion.
Diagnosis (emended). This species can be clearly distinguished from other congeners by the following set of characters: 1) anterior margin of carapace with a single moderately marked median concavity (Figs 2A, 6A); 2) spiracles small, oblique and oval to slit-like (Figs 2E, 6G; Lourenço, 2016: fig. 7); 3) pectines with 17–18 teeth (Figs 2K, 5B; Lourenço, 2016: fig. 7); 4) vesicle pear-shaped and very long, and aculeus very long and moderately curved (Figs 5E, 6I; Lourenço, 2016: fig. 4); 5) dorsal patellar spur carina well-developed with a strong tubercle and three relatively small spinous tubercles (Figs 3D, E, F, 7C, D); 6) Chela manus with two small spinous tubercles on internal surface (Figs 3G, I, J, K, 7F, G; Lourenço, 2016: figs 5, 9); 7) telotarsus with few ventrosubmedian setae and a ventromedian spinules row (Figs 2M, N, 6L, M).
Description. Carapace. Sparsely covered by fine granules without distinct carinae and furrows (Figs 2A, 6A); median eyes oval and medium sized, and separated by more than one ocular diameter (Figs 2A, 6A); PDMi posterodorsal to PLMa, and ADMi dorsal to PLMa (Figs 2B, 6B).
Coxosternal region.Surface smooth with several setae (Figs 2C, 6E); anterior margin of coxapophysis I rounded densely covered by fine setae (Figs 2C, 6E); lateral margin of sternum very long, and posterior margin of sternum slightly incurved and as long as genital operculum (Figs 2D, 6E), posterior depression region small and not obvious (Fig. 6E); genital operculum longitudinally divided and composed of two nearly rounded valves (Fig. 6F).
Chelicerae.With setae on internal and ventral surface; cheliceral dentition partly visible (Fig. 6C, D), including a long dorsal distal (dd) denticle, a small subdistal (sd) denticle, a stout median (m) denticle, a long ventral distal (vd) denticle and two small ventral accessory (va) denticle in movable finger, and distal (d) and subdistal (sd) denticles in fixed finger.
Pedipalps. Femur with five carinae (Figs 3A–C, 7A, B): internomedian carina well-developed with about five small tubercles; dorsointernal carina costate with several granules; dorsoexternal carina feebly marked with few granules; ventroexternal carina costate with few small tubercles; ventrointernal carina costate and incomplete. Patella with seven carinae (Figs 3D–F, 7C, D): Dorsal Patellar Spur carina(DPSc)andVentral Patellar Spur carina (VPSc) well-developed and each apophysis or tubercle possessing one microseta; dorsointernal, dorsomedian and dorsoexternal carinae smooth and costate; ventroexternal and ventrointernal carinae incomplete and costate. Carinae on chela not evident; Chela relatively slender (Cl/Cw = 6.19 or 6.23, Table 1); each finger denticle row consisting of about 10–11 (first row with 5) granules and a thick and short seta present beneath each accessory granule.
Trichobothrial pattern (Figs 3, 7). Pedipalp femur with 10 trichobothria, 5 dorsal, 3 internal and 2 external trichobothria, trichobothrium d 2 straddling dorsointernal carina (Fig. 7A, B) and trichobothrium e 1 proximal to trichobothrium d 5 (Figs 3A, B, 7A, B). Patella with 13 trichobothria, including 5 dorsal (d 2 petite), 1 internal and 7 external trichobothria; trichobothrium d 3 internal to dorsomedian carina and trichobothrium d 4 external to dorsomedian carina (Figs 3D, E, 7C, D). Fixed finger with 1 internal, 3 external, and 2 dorsal trichobothria. Chela manus with 6 external and 2 ventral trichobothria.
Legs. Trochanter bearing a lateral apophysis (Fig. 5B). Prolateral and retrolateral pedal spurs present on all legs (Fig. 2L–O). Ungues moderately long, dactyl pointed (Figs 2L–O, 5H, I, 6L, M).
Pectines (Figs 2K, 5B). Basal piece inverted trapezoid with an anterior median furrow (Fig. 6F). Pectines with 3 marginal lamellae and 8–9 median lamellae; fulcra present, very small. Short and transparent sensory hairs extending from surface of lamellae. Teeth elongated and terminal one ovoid, peg sensillae very short and sensory area occupied about three quarters of teeth.
Mesosoma. Tergites finely granular, median carina evident on posterior half of tergites III–VI (Figs 2F, 5A); dorsolateral carinae observed on tergites IV–VI (Fig. 2F); tergite VII with five costate carinae (Fig. 5A): paired dorsolateral and lateral carinae, and one axial carina on anterior half. Sternites covered by some fine granules and sparse setae; posterior edge of sternites I–IV incurved (Fig. 5B).
Metasoma (Figs 1A, B, 5C–E). All segments longer than width and covered by macrosetae ventrally. Segments I–IV with week 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 carinae reduced on segment III; segment V with five carinae (single ventromedian carina, paired ventrolateral and dorsolateral carinae); dorsal carinae on segments II–IV distinctly serrated, other carinae smooth to serrated.
Telson (Figs 5E, 6I). Vesicle with ventromedian and ventrosubmedian carinae evident and covered by several macrosetae ventrally, a small subaculear tuberance present on terminal of ventromedian carina and subaculear setal pair significantly evident; vesicle/aculeus juncture moderately wide and shorter than half of vesicle; aculeus with several microsetae proximally and progressively darker towards distal.
Remarks. We add some additional characters to diagnosis, i. e., the DPS of patella and telotarsus armature, which were not mentioned in the original descriptions.
description: Published as part of XUAN, QIANG, CAI, CHEN-YANG & HUANG, DI-YING, 2023, Revision of palaeoburmesebuthid scorpions in mid-Cretaceous amber from northern Myanmar (Scorpiones: Buthoidea), pp. 64-101 in Palaeoentomology 6 (1) on pages 72-73, DOI: 10.11646/palaeoentomology.6.1.10, http://zenodo.org/record/7754820