Archaeoananteroides carusoi Lourenço, 2025

Lourenço, Wilson R. & Velten, Jürgen, 2025, A new species for the genus Archaeoananteroides Lourenço, 2016, fossil scorpion from Burmite (Scorpiones: Buthoidea: Ananteridae), Faunitaxys 13 (3), pp. 1-6 : 2-4

Archaeoananteroides carusoi Lourenço sp. n.

( Fig. 1-10)

ZooBank:https://zoobank.org/ 529B5906-5DCF-409C-887C-A3535BEB8AFC

Holotype. –A male, most possibly an adult. A clear block of reddish-yellow amber that measured 41 x 26 x 3 mm. Acertain number of inclusions, mostly dust and some vegetal debris are equally present. The very marked state of ‘mumification’ of the specimen prevents a more complete observation of all characters, in particular some on the ventral aspect .

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

Patronym. – The specific name is an hommage to Mr Giuseppe Caruso, Kirchheimbolanden ( Germany) for his support to the present study.

Depository. – The type specimen is deposited in the collection of Mr Giuseppe Caruso , Kirchheimbolanden ( Germany).

Diagnosis. – The general morphology of the new species is similar to that of Archaeoananteroides maderai Lourenço, 2016 , the only known species of the genus known until now. A combination of features can however be used to diagnose the new species: a mediun to small global size when compared to A. maderai with only 11.32 mm in total length. The new species is less bulk with short metasoma and pedipalps. Carapace weakly granulated with the anterior margin clearly straight. Sternum pentagonal. Tergites with one median carinae. Sternites with moderate slit-like spiracles. Metasomal segments I and II with 10 carinae; segment III with only 8 carinae vs 10 on A. maderai ; setation on metasomal segments totally absent, while in A. maderai the setation is strongly marked. Fixed and movable fingers of pedipalp chela with 9-9 series of rounded granules and marked spinoid external and internal accessory granules. Pectines large with 14-14 teeth for a male while in A. maderai 16-16 teeth are observed for a female. Trichobothrial pattern clearly of the buthid type A (Vachon 1974): dorsal trichobothria of femur well observable and showing a β (beta) disposition ( Vachon, 1975): 4 internal, 2 external and 5 dorsal trichobothria can be observed in the femur; 1 internal and 5 dorsal trichobothria on patella; ventral totally absent; 6-7 external trichobothria can be suggested on patella by the presence of fine setae; 6 dorso-external and 2 ventral can be observed on chela hand and 6 on fixed finger. Tibial spurs present on legs III and IV but reduced compared to A. maderai .

Description

Coloration. – The scorpion is reddish-yellow to reddish-brown, mainly due to the presence of some dark zones; carapace, tergites and metasomal segments reddish-brown; pedipalps and legs yellow to reddish-yellow. Ventral aspect yellow; pectines reddish-yellow.

Morphology. – Carapace weakly granular; anterior margin clearly straight. Carinae inconspicuous; furrows weak. Median ocular tubercle inconspicuous; median eyes small, anterior to the centre of the carapace and separated by one ocular diametre; three pairs of lateral eyes. Sternum pentagonal. Mesosomal tergites not granular to smooth, with one median carina; VII with five moderately marked carinae. Pectines large, with 14-14 teeth; fulcra absent. Sternites weakly granular to smooth, with slit-like spiracles. Metasomal segments I to IV with 10-10-8-8 moderately marked carinae; segment V with five carinae; dorsal and latero-dorsal carinae of segments I-IV without any spinoid granules; dorsal aspect of segments I to V moderately depressed; setation on all segments absent. Telson moderately long with a pear-like shape. Cheliceral dentition of the buthid type; basal teeth reduced on both fingers (Vachon, 1963). Pedipalp femur pentacarinate; patella with 5-7 carinae; internal face of femur and patella without any spinoid granule. Chela with weakly marked carinae; all faces smooth; internal face of chela without any spinoid granule. Fixed and movable fingers each with 9-9 series of rounded granules and conspicuous internal and external spinoid accessory granules; extremity of fingers with one stronger spinoid granule; setation of pedipalps almost absent. Trichobothrial pattern identical to the extant buthid type A (Vachon 1974); dorsal trichobothria of femur showing a β (beta) disposition ( Vachon, 1975). For details refer to the diagnosis. Legs tarsi with thin short setae forming a brush. Tibial spurs present on legs III and IV but weakly marked.

4. Metasomal segments IV-V and telson, lateral aspect. 5. Ventral aspect showing the sternum, genital operculum and pectines. 6. Right pedipalp, dorsal aspect, showing the trichobothrial pattern.

Morphometric values (mm) of the male holotype of Archaeoananteroides carusoi Lourenço sp. n.

– Total length (including telson) 11.32.

– Carapace

length 1.47,

anterior width 0.94,

posterior width 1.14.

– Mesosoma length 2.74.

– Metasomal segments

I: length 0.81, width 0.67;

II: length 0.87, depth 0.61;

III: length 1.07, depth 0.61;

IV: length 1.21, depth 0.54;

V: length 1.54, depth 0.54.

– Telson length 1.61.

– Vesicle depth 0.41.

– Pedipalp

femur length 1.41, width 0.47;

patella length 1.27, width 0.47;

chela length 2.21, width 0.41, depth 0.47;

movable finger length 1.54.

Relationships. – In summary, the new species can be separated from Archaeoananteroides maderai by a number of features:

(i) a smaller global with, 11.32 mm,

(ii) less bulk metasoma and pedipalps,

(iii) carapace with the anterior margin clearly straight,

(iv) metasomal segment III with only 8 carinae,

(v) setation on metasomal segments totally absent,

(vi) pectines with 14-14 teeth for a male while in A. maderai 16-16 teeth are observed for a female,

(vii) tibial spurs reduced.