Cretaceoushormiops petersi Lourenço, 2025

Cretaceoushormiops Lourenço, 2018

Cretaceoushormiops petersi Lourenço sp. n.

( Fig. 1-13)

ZooBank:https://zoobank.org/ 4FFAF15E-954D-4CB2-9A91-DD491C72645F

Holotype. – A possible juvenile or pre-adult. According to the morphology of pectines and genital operculum, with two oval plates, the specimen can be defined as a male.

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

Name. – Honors Mr Thorsten Peters (Gelsenkirchen, Germany) who arranged facilities for the study of the specimen.

Depository. – The type specimen is deposited in the Collection of Mr Thorsten Peters (Gelsenkirchen, Germany) .

Diagnosis for the new species. – Total length 13.18 mm (to notice that the body and mesosoma are strongly elongated). General coloration yellow to bright yellow. Carapace with a straight median concavity; median ocular tubercle markedly anterior to the centre of the carapace and with reduced median eyes; two lateral eyes can be observed. Sternum pentagonal in shape; slightly larger than long. Pectines moderate to large in size with 13-12 teeth; fulcra inconspicuous. Spiracles slightly oval. Metasomal segment I to V rounded and weakly flattened laterally with only dorsal and latero-dorsal carinae. Telson with

a long pear-shaped vesicle weakly flattened laterally; no annular ring on the telson is observed. Fixed and movable fingers with one row of small rounded granules, without clear accessory granules; presence of 3-4 spinoid granules on the distal third of fingers; each finger terminating by a moderately to weakly marked spinoid process. Chelicerae not clearly observed but probably showing a dentition similar to that defined for the Scorpionidae sensu Vachon (1963) . Tibial spurs absent; tarsi with two rows of thin spines. Trichobothrial pattern similar to type C defined by Vachon (1974) and also illustrated by Lourenço & Monod (1999) for the genus Hormiops . On the chela hand, trichobothria Db, Dt, Est, Et 1-5, Esb, Eb 1 to Eb 3 and four V can be observed. On the chela fixed finger, trichobothria eb, db, dsb, esb, dst, dt, est, et, ib and it can be observed. Patella shows d 1 and d 2 on dorsal face; i on internal face; on the ventral face 4 V trichobothria are clearly observed. Accessory ventral trichobothria have being previously observed for extant Hormuridae species; e. g. Liocheles penta Francke & Lourenço, 1991 ( Francke & Lourenço, 1991). 10-11 external trichobothria can be directly observed on the patella, but the presence of other transverse hairs suggests a higher number reaching a total of 12-13, which belong to territories et, est, esb, em, esb and eb. Femur shows one d, one i and one e.

Description

Coloration. – The scorpion is yellow to pale-yellow; carapace and tergites yellow; metasomal segments I to V yellow; telson yellow; pedipalps and legs yellow to slightly reddish-yellow. The ventral aspect of the specimen is yellow to pale yellow.

5-6. Chela dorso-external and ventral aspects. 7-8. Patella, dorsal and ventral aspects. 9. Femur, dorsal aspect.

Morphology. – Carapace without granulations, almost smooth; anterior margin straight. Carinae absent; furrows weakly marked to absent. Median ocular tubercle markedly anterior to the centre of carapace; median eyes strongly reduced in size and separated by about two ocular diameters. Two pairs of lateral eyes. Sternum pentagonal, slightly larger than long. Mesosomal tergites weakly observed but without granulations, smooth, with one median vestigial carina; VII with five inconspicuous carinae. Pectines moderate to large in size with 13-12 teeth; fulcra inconspicuous. Sternites smooth with small slightly oval spiracles. Metasomal segment I to V rounded and weakly flattened laterally with only dorsal and latero-dorsal carinae; dorsal carinae of segments I to IV without any spinoid granules; dorsal aspect of segments I to V weakly depressed; setation on all segments weakly marked. Telson with a long pear-shaped vesicle weakly flattened laterally; not granular, smooth; aculeus short and moderately curved; absence of any annular ring on the telson; setation conspicuous. Cheliceral dentition very weakly visible but probably similar to that defined for the Scorpionidaesensu Vachon (1963). Pedipalp femur pentacarinate with some internal spinoid granules; patella with dorso-internal, ventro-internal, and dorso-external carinae; internal face withouy spinoid granules and one weak apophysis. Chela with weakly marked carinae; all faces smooth. Fixed and movable fingers each with one row of small rounded granules; no accessory granules are observable but3-4 spinoid granules onthe distal third of fingers can be observed; each finger terminating by a weakly marked spinoid process; setation of pedipalps weak to moderate. Tibial spurs absent; tarsi with two rows of small thin spines. Trichobothriotaxy similar to type C ( Vachon, 1974) of extant Hormuridae scorpions ( Lourenço & Monod, 1999). For details refer to the diagnosis.

Relationships. – Most characters observed for this new species allow its inclusion in the genus Cretaceoushorpiops . Nevertheless, a few characters such as the presence of thin spines on the tarsi, instead of only setae and the confirmed presence of four ventral trichobothia in the patella, could suggest a generic difference. However, as already stated before ( Lourenço & Velten, 2022), the possible creation of a new genus is here rejected, particularly because these variations have already been observed in extant species of the Hormuridae family, but mostly because the number of studied specimens remains quite limited.

The new species of Cretaceoushormiops can however be distinguished from the three others previously described by a number of features:

(i) total length 13.18 with a body and mesosoma very elongated,

(ii) carapace with a straight median concavity,

(iii) median ocular tubercle markedly anterior to the centre of the

carapace with extremely reduced median eyes,

(iv) telson with a weakly elongated vesicle,

(v) patella with four ventral trichobothria.

Comparative morphometric values (mm) between the holotypes of Cretaceoushormiops knodeli Lourenço , Cretaceoushormiops staxi Lourenço and Cretaceoushormiops petersi Lourenço sp. n.

– Total length (including telson) 12.83/11.30/13.18.

– Carapace

length 1.80/1.87/1.88,

anterior width 0.94/1.20/0.94

posterior width 1.60/1.74/1.20.

– Mesosoma length 5.07/3.65/4.94.

– Metasomal segments

I: length 0.67/0.74/0.81, width 0.34/0.47/0.61;

II: length 0.74/0.74/0.81, width/depth 0.34/0.47/0.61; III: length 0.80/0.81/088, depth/width 0.34/0.47/0.54; IV: length 0.94/0.87/0.95, depth/width 0.34/0.47/0.47; V: length 1.27/1.14/1.29, depth/width 0.47/0.41/0.41.

– Telson length 1.54/1.48/1.62.

– Vesicle depth/width 0.44/0.41/0.34/0.47.

– Pedipalp

femur length 1.54/1.61/1.34, width 0.54/0.54/0.54;

patella length 1.60/1.68/1.74, width 0.60/0.68/0.55;

chela length 3.14/3.30/3.65, width 0.54/0.76/0.55.

movable finger length 1.87/1.78/2.15