Betaburmesebuthus bellus, Lourenco, Wilson R., 2016

Lourenco, Wilson R., 2016, A preliminary synopsis on amber scorpions with special reference to Burmite species: an extraordinary development of our knowledge in only 20 years, ZooKeys 600, pp. 75-87 : 78-82

Taxon classification Animalia Scorpiones Palaeoburmesebuthidae

Betaburmesebuthus bellus sp. n. Figures 1-4, 5-7, 8-9, 10

Holotype.

A juvenile, most certainly a male. Very clear block of pale yellow amber that measured 21.5 × 17.0 × 2 mm. Only a few inclusions and bubbles prevent a 100% observation of all characters. Type locality and horizon: Myanmar (Burma), Kachin; precise locality unknown; Lower Cretaceous.

Etymology.

The specific name is an epythet from Latin “bellus” meaning beautiful, elegant.

Repository.

The type specimen is deposited in the collection of the Museum of the Geological-Palaeontological Institut of the University of Hamburg (CeNak - Centrum of Natural History), Coll. N° 4586, Coll. Gröhn N° 11086.

Diagnosis.

General morphology is globally similar with other species of the genus Betaburmesebuthus Lourenço, 2015 and also with extant buthoid scorpions. The following combination of features can be used to diagnose the new species: Carapace weakly to moderately granulated; anterior margin with a moderately marked median concavity. Sternum subpentagonal. Tergites with three carinae, the lateral totally inconspicuous. Sternites with small oval to slit-like spiracle. Metasomal segments I and II with ten carinae; setation on all metasomal segments strongly marked. Fixed and movable fingers of pedipalp chela with a series of small rounded granules and no conspicuous spinoid accessory granules. Trichobothrial pattern with elements ressembling those of extant buthid type A ( Vachon 1974): at least 1-3 internal, five dorsal, and two external trichobothria on the femur; dorsal trichobothria disposed in beta (β) configuration ( Vachon 1975); one internal and five dorsal trichobothria on patella; 6-7 external trichobothria can be suggested on patella by the presence of fine setae; some are displaced on ventral aspect; 4-5 dorso-external and two ventral on chelal hand; six on fixed finger. Tibial spurs present on legs III and IV.

Description.

Coloration: the scorpion is yellow to slightly reddish-yellow; carapace and tergites yellow; metasomal segments yellow; telson reddish-yellow; pedipalps and legs yellow. Ventral aspect yellow; coxapophysis slightly darker than dorsal aspect.

Morphology.

Carapace weakly granular; anterior margin with a moderately marked median concavity. Carinae inconspicuous; furrows weak. Median ocular tubercle clearly anterior to the centre of carapace; median eyes moderate in size and separated by more than one ocular diameter. Three pairs of lateral eyes of moderate size. Sternum subpentagonal. Mesosomal tergites weakly granular, with one median carina; lateral carinae totally inconspicuous; VII with five weakly marked carinae. Pectines large, with 18-17 teeth; fulcra absent. Sternites weakly granular to smooth, with small oval to slit-like spiracles. Metasomal segment I to IV rounded with 10-10-8-8 carinae; segment V slender with five carinae; dorsal carinae of segments I-IV with minute spinoid granules; dorsal aspect of segments I to V weakly depressed; setation on all segments strongly marked. Telson with a very long pear-shaped vesicle; weakly granular to smooth; aculeus extremely long and moderately curved; setation strongly marked. Cheliceral dentition only partially visible; fixed and movable fingers with one basal tooth observable; distal teeth moderately long (Vachon 1963). Pedipalp femur pentacarinate; patella with 6-7 carinae; internal face of femur and patella with spinoid granules. Chela with weakly marked carinae; all faces not granular, smooth. Fixed and movable fingers each with one series of small rounded granules and no conspicuous spinoid accessory granules; extremity of fingers with stronger spinoid granules; setation of pedipalps weakly marked. Trichobothriotaxy recalling type A ( Vachon 1974) of extant buthids: at least 1-3 internal, five dorsal, and two external trichobothria on the femur; dorsal trichobothria disposed in beta (β) configuration ( Vachon 1975); one internal, five dorsal, and no ventral trichobothria on patella; 6-7 external trichobothria can be suggested on patella by the presence of fine setae; some are displaced on the ventral aspect 5-6 dorso-external and two ventral on chelal hand; six on fixed finger. Tibial spurs present on legs III and IV, moderately marked.

Morphometric values (in mm) of male juvenile holotype of Betaburmesebuthus bellus sp. n.

Total length 11.80 (including telson). Carapace: length 1.40, anterior width 0.87, posterior width 1.40. Mesosoma length 3.60. Metasomal segments. I: length 0.74, width 0.60; II: length 0.84, width 0.60; III: length 0.94, depth 0.57; IV: length 1.14, depth 0.50; V: length 1.67, depth 0.47. Telson length 1.47. Vesicle: depth 0.37. Pedipalp: femur length 1.14, width 0.34; patella length 1.24, width 0.47; chela length 2.24, width 0.34; movable finger length 1.57.