Betaburmesebuthus kobberti Lourenço & Beigel, 2015

XUAN, QIANG, CAI, CHEN-YANG & HUANG, DI-YING, 2023, Revision of palaeoburmesebuthid scorpions in mid-Cretaceous amber from northern Myanmar (Scorpiones: Buthoidea), Palaeoentomology 6 (1), pp. 64-101 : 73-77

Betaburmesebuthus kobberti Lourenço & Beigel, 2015

( Figs 8–11 )

Material. NIGP 200650, one probable juvenile male, the part of pedipalp fingers damaged, amber containing many impurities.

Diagnosis (emended). This species can be clearly distinguished from the congeners by the following set of characters: 1) anterior margin of carapace with a single moderately marked median concavity ( Figs 9A , 10A ; Lourenço & Beigel, 2015: fig. 1); 2) spiracles small, round ( Fig. 10E ; Lourenço & Beigel, 2015: figs 2, 3); 3) pectines with about 20 teeth ( Fig. 10F ; Lourenço & Beigel, 2015: fig. 2); 4) vesicle pear-shaped and very long, and aculeus extremely long and moderately curved ( Fig. 9E, F ; Lourenço & Beigel, 2015: fig. 4); 5) dorsal patellar spur carina with at least one strong tubercles ( Fig. 11A ; Lourenço & Beigel, 2015: fig. 7); 6) Chela manus without obvious tubercles on internal surface ( Fig. 11A, E ); and 7) telotarsus with few ventrosubmedian setae and a ventromedian spinules row ( Fig. 10I, J ).

Description. Carapace. Sparsely covered by fine granules without distinct carinae, and posterior median furrow observed ( Figs 9A , 10A ); median eyes oval and medium sized, and separated by one ocular diameter ( Fig. 10A ); PDMi posterodorsal to PLMa, and ADMi posterior to PLMa ( Fig. 10B ).

Coxosternal region. Surface smooth with several setae ( Fig. 10C ); anterior margin of coxapophysis I rounded ( Figs 2C , 6E ); genital operculum not visible.

Chelicerae.With setae on internal and ventral surfaces ( Fig. 9A, B ); cheliceral dentition not visible except a long dorsal distal (dd) denticle ( Fig. 9A ).

Pedipalps. Femur with two carinae observed ( Fig. 11A, B ): dorsointernal carina feebly serrated; dorsoexternal carina costate and relatively smooth. Patella with three carinae observed ( Fig. 11A, B ): dorsointernal, dorsomedian and dorsoexternal carinae smooth and costate; Chela relatively slender (Cl/Cw = 6.82, Table 1 ); finger dentition not visible.

Trichobothrial pattern ( Fig. 11 ). Trichobothria not clear and partly observed. Femur with 10 trichobothria, 5 dorsal, 3 internal and 2 external trichobothria, trichobothrium e 1 proximal to trichobothrium d 5 ( Fig. 11A ). Patella with 13 trichobothria, including 5 dorsal (d 2 petite), 1 internal and 7 external trichobothria ( Fig. 11A ); trichobothrium d 3 external or straddling to dorsomedian carina, trichobothrium d 4 external to dorsomedian carina. Fixed finger with 3 external, and 2 dorsal trichobothria observed. Chela manus with 4 external and 2 ventral trichobothria observed.

Legs. Prolateral and retrolateral pedal spurs present on all legs. Ungues moderately long, dactyl pointed ( Fig. 10J ).

Pectines ( Fig 10F ). Basal piece not visible. Pectines folded, only 17 teeth observed, lamellae boundary not clear. 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 II–VI ( Fig. 10D ); dorsolateral carinae evident on tergites III and VI ( Fig. 10D ); tergite VII with five costate carinae ( Fig. 10G ): paired dorsolateral and lateral carinae, and one axial carina on anterior half. Sternites covered by few setae ( Fig. 10E ).

Metasoma ( Figs 9C–F , 10G ). All segments longer than width and covered by macrosetae ventrally. Dorsal depression on segments I–II observed; segments I and II with ten carinae (paired ventromedian, ventrolateral, lateral, dorsolateral, and dorsal carinae); segments III and IV with eight carinae (paired ventromedian, ventrolateral, dorsolateral, and dorsal carinae); segment V with five carinae (single ventromedian carina, paired ventrolateral and dorsolateral carinae).

Telson ( Figs 9E, F , 10H ). Vesicle with a lateral longitudinal furrow, ventromedian carina welldeveloped, ventrosubmedian and dorsolateral carinae costate, covered by several macrosetae ventrally, one or two small subaculear tuberance present on terminal of ventromedian carina; vesicle/aculeus juncture moderately wide and shorter than half of vesicle; aculeus with several microsetae proximally.

Figures

FIGURE 2. Details of Betaburmesebuthus bellus, NIGP200648, under confocal microscopy with depth color-coding. A, Carapace. B, Lateral ocelli. C, Coxapophysis, coxa and trochanter of leg I. D, Sternum and genital operculum. E, Spiracle of sternite VI. F, Tergites I–VI. G, Dentition of movable finger. H, Dentition of fixed finger. I, Tibial spur of leg III. J, Tibial spur of leg IV. K, Left pectine. L–O, Telotarsi of legs I–IV.Abbreviations:ADMi, anterodorsal minor ocellus; ALMa, anterolateral major ocellus; MLMa, mediolateral major ocellus; PDMi, posterodorsal minor ocellus; PLMa, posterolateral major ocellus; sp, spiracle; ts, tibial spur. Scale bars = 200 μm in A, F, G, K; 100 μm in C, D, E, H, I, J, L, M, N, O; 50 μm in B.

FIGURE 6. Details of Betaburmesebuthus bellus, NIGP200649, under confocal microscopy. A, Carapace. B, Lateral ocelli. C, Chelicerae, dorsal view. D, Chelicerae, ventral view. E, Coxosternal region. F, Genital operculum and basal piece. G, Spiracles. H, Dentition of movable finger. I, Telson. J, Tibial spur of leg III. K, Tibial spur of leg IV. L, Telotarsi of leg IV. M, Telotarsi of leg III. Abbreviations:ADMi, anterodorsal minor ocellus; ALMa, anterolateral major ocellus; MLMa, mediolateral major ocellus; PDMi, posterodorsal minor ocellus; PLMa, posterolateral major ocellus; sp, spiracle; st, subaculear tubercle; ts, tibial spur. Scale bars = 200 μm in A, E, G, H; 100 μm in C, D, F, I, J, K, L, M; 50 μm in B.

FIGURE 8. General habitus of Betaburmesebuthus kobberti, NIGP200650, under incident light. A, Dorsal view. B, Ventral view. Scale bars = 1 mm.

FIGURE 9. Details of Betaburmesebuthus kobberti, NIGP200650, under green epifluorescence. A, Carapace, chelicerae and left pedipalp, dorsal view. B, Coxosternal region, left pedipalp, ventral view. C, Tergite VII and metasomal segments I–II, dorsal view. D, Tergite VII and metasomal segments I–II, ventral view. E, F, Metasomal segments III–V and telson, lateral view. Scale bars = 400 μm.

FIGURE 10. Details of Betaburmesebuthus kobberti, NIGP200650, under confocal microscopy. A, Carapace. B, Lateral ocelli. C, Coxapophyses I–II. D, Tergites I–VI. E, Sternites IV–VII. F, Pectine. G, Tergite VII and Metasomal segments I–II. H, Telson. I, Tibial spur of leg II. J, Tibial spur of leg IV. K, Telotarsi of leg III. L, Telotarsi of leg IV. Abbreviations: ADMi, anterodorsal minor ocellus; ALMa, anterolateral major ocellus; MLMa, mediolateral major ocellus; PDMi, posterodorsal minor ocellus; PLMa, posterolateral major ocellus; sp, spiracle; st, subaculear tubercle; ts, tibial spur. Scale bars = 200 μm in A, D, E, F, G, H; 100 μm in C, I, J, K, L; 50 μm in B.

FIGURE 11. Trichobothrial pattern of Betaburmesebuthus kobberti, NIGP200650, under confocal microscopy. A, Left femur, patella and chela, dorsal view. B, Left femur, patella and chela, ventral view. C. Left femur and fixed finger, dorsal view. D, Right fixed finger, dorsal view. E, Right chela, dorsal view. Scale bars = 200 μm.