Chaerilobuthus enigmaticus Lourenço, 2015

Chaerilobuthus enigmaticus Lourenço, 2015

( Figs 17–21 View Figure 17 View Figure 18 View Figure 19 View Figure 20 View Figure 21 , 39 View Figure 39 )

Chaerilobuthus enigmaticus Lourenço, 2015: 44–48 , figs 1–6.

Type material: Holotype: one juv. ♀ (personal collection of Patrick Müller, Käshofen, Germany), Cretaceous (Cenomanian) burmite: MYANMAR: Kachin State (precise locality unknown) .

Diagnosis: The following combination of characters is diagnostic for C. enigmaticus : carapace anteromedian margin slightly posterior to anterolateral margins ( Figs 17A View Figure 17 and 18D View Figure 18 ); lateral ocelli not protruding, macular ( Figs 18D View Figure 18 , 20A View Figure 20 ); pedipalp chela moderately robust, manus globose, ratio of chela length: chela manus width less than 4 ( Figs 18A, B View Figure 18 , 21A View Figure 21 ); pectines each with five teeth ( Figs 18I View Figure 18 , 20F, G View Figure 20 ); ratio of metasomal segment IV: V length greater than 2 ( Figs 18A, B View Figure 18 , 20H, I, L View Figure 20 ); metasomal segment V dorsosubmedian carinae slightly serrate ( Fig. 20L View Figure 20 ); telson vesicle bulbous, aculeus very short and moderately curved ( Figs 18G, J, K View Figure 18 , 19 View Figure 19 ).

Description: Based on the material examined (NIGP 201158, 201159).

Carapace: Posterior width less than length (L/PW = 1.16, Appendix 2). Anterior margin with few, short microsetae; anteromedian depression not visible; anterosubmedial depressions absent; lateral ocular carinae absent; posteromedian and posteromarginal sulci obsolete; surfaces almost smooth to sparsely and finely granular ( Fig. 20A, B View Figure 20 ). Median ocular tubercle situated anteromedially; median ocelli absent; one pair of large posterolateral major lateral ocelli present.

Coxosternalregion: Surfacesmooth,sparselycoveredinmacrosetae ( Figs 20E View Figure 20 , 39B, C View Figure 39 ). Leg I maxillary lobes (coxapophyses) distal margins slightly curved, dilate anteriorly and adorned with serrula comprising c. 15 denticles ( Fig. 39B, C View Figure 39 ). Sternum pentagonal; lateral margins sublinear, parallel; ventral surface flat, without distinct concave region or median sulcus; posteromedian depression wide, shallow ( Figs 17A View Figure 17 , 20E View Figure 20 ).

Chelicerae: Fixed finger and manus, prolateral and ventral surfaces each with numerous long, dense macrosetae ( Fig. 18E, F View Figure 18 ). Cheliceral dentition partly visible, moveable finger with long dorsal distal (dd) denticle, small dorsal subdistal denticle, stout dorsal median denticle, long ventral distal (vd) denticle and four or five small ventral accessory (va) denticles; fixed finger with long distal denticle and small subdistal denticle ( Figs 18E, F View Figure 18 , 20C View Figure 20 ). Moveable finger with prominent serrula comprising long spinules in proximal three-quarters ( Fig. 18F View Figure 18 ).

Pedipalps: Segments moderately robust; surfaces sparsely covered by short microsetae and few macrosetae ( Figs 18A, B View Figure 18 , 21A View Figure 21 ). Femur with four carinae evident; prodorsal and proventral carinae distinct, serrate; retrodorsal and retroventral carinae smooth, costate ( Figs 18A View Figure 18 , 21A, C View Figure 21 ). Patella with five carinae evident; prodorsal carina obsolete, comprising several tubercles; prolateral surface, dorsoventral ‘vaulted’ projection (‘anterior process’) distinct with prominent pair of apophyses or tubercles (‘patellar spurs’), each possessing one macroseta; retrodorsal and retroventral carinae smooth, costate ( Figs 18A, B View Figure 18 , 21A, D View Figure 21 ). Chela relatively robust (CL/CW = 3.22 or 3.55, Appendix 2); manus globose; chela with six carinae evident; digital carina complete, distinct, granular medially, becoming costate proximally and distally; dorsomedian carina reduced to few granules at base of fixed finger, becoming obsolete proximally on manus; prodorsal carina distinct, comprising several prominent spiniform granules; promedian and proventral carinae obsolete, each comprising few isolated granules; retroventral carina obsolete; dorsal secondary, subdigital, retromedian and ventromedian carinae absent or obsolete ( Figs 18A, B View Figure 18 , 21A, B, E, F View Figure 21 ). Only fixed finger distal denticle subrows visible, oblique, slightly imbricate and separated by large serrate prolateral and retrolateral denticles ( Fig. 21A View Figure 21 ). Trichobothrial pattern Type D, β configuration. Femur with three trichobothria visible: two d and one i trichobothria ( Fig. 21C View Figure 21 ). Patella with six trichobothria visible, including three d, one i, and two e trichobothria; trichobothrium i 1 situated distal to trichobothrium d 3 ( Fig. 21A, D View Figure 21 ). Chela with 10 trichobothria visible; fixed finger with two d and one i trichobothria; manus with four E and one V trichobothria; trichobothrium Et 1 situated distally on manus, almost aligned with or proximal to moveable finger condyle; trichobothrium eb situated on fixed finger, slightly distal to moveable finger condyle; trichobothrium esb situated medially on fixed finger; trichobothrium V 2 situated distally on manus and near retroventral carina.

Legs: Tibia lateral and ventral surfaces each with scattered macrosetae ( Fig. 18C View Figure 18 , 20J, K View Figure 20 ). Basitarsi each with pair of spinule rows, comprising c. 10 relatively long spinules, distally. Telotarsi each with slightly irregular pair of ventrosubmedian spinule rows, comprising relatively long spinules. Ungues moderately long, distinctly curved; dactyl pronounced, pointed.

Pectines: Basal piece long, narrow ( Fig. 20F View Figure 20 ). Three marginal lamellae and four median lamellae; surface sparsely covered in macrosetae; longitudinal suture between marginal and median lamellae distinct ( Figs 18I View Figure 18 , 20G View Figure 20 ). Fulcra absent or obsolete. Teeth rounded, distal three-quarters of each tooth occupied by sensillar field; peg sensilla very long, columnar ( Fig. 20G View Figure 20 ).

Genital operculum: Two opercular sclerites narrow and completely separated, as long as pectinal plate; surfaces with several microsetae ( Fig. 20E View Figure 20 ).

Mesosoma : Pretergites surfaces almost smooth ( Fig. 19A View Figure 19 ); post-tergites I–VI surfaces finely granular, acarinate ( Fig. 19A View Figure 19 ); tergite VII surface sparsely granular, with four slightly serrate carinae (paired dorsosubmedian and dorsolateral carinae) in posterior half of segment ( Fig. 20H View Figure 20 ). Sternites surfaces smooth, with scattered macrosetae; posterior margins broadly recurved; respiratory spiracles small, ovoid, oblique ( Figs 18H View Figure 18 , 20D View Figure 20 ).

Metasoma: Segments I–V progressively increasing in length, I wider than long, others longer than wide ( Fig. 18J, K View Figure 18 , 20H, I, L View Figure 20 ). Segments I–V lateral and ventral surfaces each with few, short macrosetae ( Fig. 18J, K View Figure 18 , 20H, I, L View Figure 20 ); I–IV dorsal surfaces each with distinct depression ( Figs. 18K View Figure 18 , 20H View Figure 20 ). Segment I with six distinct carinae (paired dorsosubmedian, dorsolateral, and ventrolateral carinae), segments II–V each with eight distinct carinae (paired dorsosubmedian, dorsolateral, ventrolateral, and ventrosubmedian carinae); dorsosubmedian carinae distinct on all segments, markedly serrate on II–IV, moderately serrate, converging posteriorly on I and V; dorsolateral carinae distinct, moderately serrate on segments I, II and V, slightly serrate on III and IV; ventrolateral carinae distinct, moderately serrate on segments I–IV, markedly serrate on segment V; ventrosubmedian carinae absent on segment I, obsolete on II and III, distinct, moderately serrate on IV and V, and converging posteriorly on V ( Fig. 18J, K View Figure 18 , 20H, I, L View Figure 20 ).

Telson: Vesicle bulbous; dorsal surface flat; lateral and ventral surfaces relatively smooth with several macrosetae; ( Figs 18G View Figure 18 , 19A, B View Figure 19 ); subaculear tubercle absent; prominent subaculear setal pair, moderately long. Aculeus short, shallowly curved; base narrow, less than one-third vesicle width.

Material examined: MYANMAR: Kachin State: Noije Bum near HukawngValley,preciselocalityunknown, Cretaceous (Cenomanian) burmite: two juv. (sex unknown) ( NIGP 201158 View Materials , 201159 View Materials ) .