Cretaceousbuthus petersi Lourenço, 2023,

Cretaceousbuthus petersi Lourenço, 2023 sp. n.

( Fig. 1 -13)

ZooBank:http://zoobank.org/ DB872688-92C1-4D43-AE5F-E5EB3A9D7ABF

Holotype. Possibly a female, pre-adult or a juvenile depending on the number of molts yet necessary to reach adult stage. The scorpion is represented by an exuviae, incomplete but rather well preserved in a clear block of pale-yellow amber measuring 0.5 x 7.5 x 1.0 mm. A great number of inclusions are also present, represented by some vegetal debris and particularly some type of ‘black sand’ which largely covers the carapace, chelicerae and pedipalps.An insect leg is also included in the piece.

Diagnosis for the new species. – Having in account that the specimen is a juvenile exuvia, the overall size of 16.9 mm is rather large when compared to other scorpions previously found in Burmite; an estimated total length could range from 40 to 50 mm. Specimen rather bulk with short pedipalps. Carapace moderately granulated; anterior margin with a deep concavity. Median eyes large and anterior to the centre of the carapace;three pairs of conspicuous lateral eyes. Sternum sub-pentagonal to almost triangular. Sternites are largely destroyed, but one spiracle apparently is small and slit-like to oval. Metasomal segments I to IV apparently with with 10 carinae; this is at least confirmed for IV ( Fig. 5). Telson pear-like shaped with a conical sub-aculear tooth.Trichobothrial pattern similar to that of extant buthid type A ( Vachon 1974); the dorsal trichobothria of femur presenting a beta disposition ( Vachon, 1975). Femur orthobothriotaxic with 4 internal, 5 dorsal and 2 external. d 5 and e 1 not in the same position. Patella minorante neobothriotaxic with 1 internal, dorsal d 1 and d 2, d 3 and d 5; absence of d 4; a number of external trichobothria can be observed; ventral trichobothria absent. Chela with at least four trichobothria on fixed finger, dt, db, esb and eb and one in the hand, possibly Esb.

Tibial spurs present on legs III and IV, small in size. Pedal spurs present in all legs.

Type locality and horizon. – Myanmar ( Burma), Kachin; precise locality unknown; Lower Cretaceous .

Patronym. – The specific name honors Mr Thorsten Peters, Gelsenkirchen, Germany, who supported the present study.

Depository. - The type specimen is deposited in the collections of Mr Thorsten Peters , Gelsenkirchen, Germany .

1. Carapace. 2. Chelicera, dorsal aspect. 3. Fixed finger, showing the rows of granules. 4. Ventral aspect showing coxapophysis, sternum, genital operculum, one pecten and torn sternite III with the vestige of a spiracle [scale bars = 1 mm (1, 4), 0.5 mm (2, 3)].

5. Metasomal segments IV, V and telson, lateral aspect, showing the conical sub-aculear tooth and 10 carinae on segment IV (scale = 1 mm).

pattern. 6 - 7. Chela dorsal and ventral aspects. 8 -9. Patella and femur, dorsal mm).

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Description

Coloration. –The scorpion is yellow to pale yellow with some reddish zones on carapace and pedipalps; actually, the exuviae is embbebed in a rather clear amber resin, consequently, some parts are translucid allowing even observations by transparency. Only the areas covered by the black dust prevent a good observation.

Morphology. – Carapace moderately granular, mostly in the anterior region; anterior margin with a strong concavity. Carinae inconspicuous; furrowsweak. Median ocular tubercle anterior to the centre of the carapace; median eyes large and separated by less than one ocular diameter; three pairs of conspicous lateral eyes. Sternum subpentagonal to triangular. Genital operculum with two semi-oval to round plates. Mesosomal tergites weakly granular to smooth, with one median carina; lateral carinae, if present, totally inconspicuous; VII with five carinae; the lateral weak and the internal inconspicous. Pectines large, with 17-? teeth; fulcra absent. Sternites apparently smooth; the ventral side of the exuvia was torn up during the process of trapping; one apparently small slit-like to oval spiracle is poorly observed. Metasomal segments I to IV apparently with 10 carinae; at least on IV these are clearly observed; dorsal carinae with some stronger posterior granules; all segments are rounded, in particular V. Telson pear-like shaped, smooth with one ventral carinae; sub-aculear tooth conical. Chelicera with buthid type dentition (Vachon, 1963); fixed and movable fingers with two small basal teeth. Pedipalp femur pentacarinate; patella with 6-7 carinae; both segments strongly granular; internal face of femur and patella with spinoid granules; chela short and slightly bulk with some moderate carinae; internal face with some spinoid granules; chela fingers with 10-11 rows of small granules, separated by bigger central accessory granules. Trichobothrial pattern similar to the extant buthid type A ( Vachon 1974); dorsal trichobothria of femur in beta configuration ( Vachon, 1975). See diagnosis for details. Legs tarsi with thin setae forming more or less a brush. Tibial spurs present on legs III and IV, weakly marked; pedal spurs present on legs I-IV weak to moderate in size.

Morphometric values (mm), holotype of Cretaceousbuthus petersi Lourenço, 2023 sp. n.

– Total length (including telson) 16.9.

– Carapace length, 2.0;

anterior width, 1.4;

posterior width, 2.2.

– Mesosoma : length, 4.2.

– Metasomal segments

I: length, 1.2; width, 1.3;

II: length, 1.4; width, 1.2;

III: length, 1.5; width, 1.2;

IV: length, 1.8; width, 1.2;

V: length, 2.4; width, 1.0; depth, -.

– Telson: length, 2.4; width, -; depth, 0.8.

– Pedipalp femur length, 2.1, width, 0.6;

patella length, 2.2, width, 0.8;

chela length, 3.1, width, 0.7, depth, -;

movable finger length, 2.7.

Other species also examined during this study

Chaerilobuthus schwarzi Lourenço, 2015 (Family Chaerilobuthidae ) A very small juvenile with the following measurements (in mm): total length of 4.16, carapace 0.84, prosoma 0.90, metasoma 1.68, telson 0.74. Specimen included in a clear yellow piece sizing 10.5 x 7.5 x 1 mm. The piece equally contains an insect, a possible nymph of Blattodea, which was trapped near to the scorpion; impossible to suggest if it was a potential prey. The species is clearly characterised by the shape and size of the telson, the size of pectines and number of teeth, 5-4 and the typical carinae on femur, patella and chela of pedipalps ( Fig. 14-15).