Halitherses grimaldii, Giribet & Dunlop, 2005

BARTEL, CHRISTIAN & DUNLOP, JASON A., 2023, First eupnoid harvestmen (Arachnida: Opiliones: Eupnoi) from mid-Cretaceous Kachin amber, with notes on sexual dimorphism in Halitherses grimaldii (Arachnida: Opiliones: Dyspnoi), Palaeoentomology 6 (3), pp. 278-291 : 286-287

publication ID	https://doi.org/ 10.11646/palaeoentomology.6.3.11
publication LSID	lsid:zoobank.org:pub:339DF6C2-7D16-4BAC-9428-B741F557717C
DOI	https://doi.org/10.5281/zenodo.8209335
persistent identifier	https://treatment.plazi.org/id/E7240C06-FF8D-686C-FF72-9697FE576EA6
treatment provided by	Plazi
scientific name	Halitherses grimaldii
status

Treatment

Species Halitherses grimaldii View in CoL (?) Giribet & Dunlop, 2005

( Fig. 6 View FIGURE 6 )

Material. MB.A.4458 (ex coll. Jörg Wunderlich, F2723).

Locality and horizon. Burmese amber, Hukawng Valley, Kachin State, Myanmar; mid-Cretaceous.

Description. Body oval and dorsally completely ornamented, L 1.38. Prosoma dominated by an extremely large, strongly ornamented and bilobed ocularium, L 0.34, W 0.62 ( Fig. 6A View FIGURE 6 ). Eye lenses also very large (eye lens diameter 0.22). Dorsal segments fused into scutum parvum with free metapeltidium. Chelicerae moderately sized, distal segment with a dorsal, claw-like and curved apophysis proximally (apophysis L 0.09) ( Fig. 6B–D View FIGURE 6 ). Distal segment additionally covered with a few small setae. Cheliceral fingers bearing small spines or thicker setae distally. Cheliceral basal segment L?, distal segment L 0.23, finger L 0.19. Pedipalps long and slender. Pedipalp tarsus and tibia covered with numerous clavate glandular setae. Pedipalp tarsus lacks terminal claw ( Fig. 6B, D View FIGURE 6 ). Pedipalp length: tr 0.26, fe 1.16, pa 0.52, ti 0.50, ta 0.42, total (tr–ta) 2.86. Legs extremely long and slender. Leg femur sparsely covered with small spines ( Fig. 6A View FIGURE 6 ). Coxa strongly ornamented ( Fig. 6C View FIGURE 6 ). Tarsus I–IV subdivided, ending in a single claw. Leg length: Leg I cx 0.55, tr 0.18, fe?, pa?, ti?, mt?, ta?; Leg II cx 0.66, tr?, fe?, pa?, ti?, mt?, ta?; Leg III cx 0.74, tr 0.18, fe 6.33, pa 0.92, ti 4.83, mt?, ta?, total (cx–ti) 13; Leg IV cx 0.82, tr 0.23, fe 7.50, pa 0.83, ti?, mt?, ta?, total (cx–pa) 9.38.

Genital operculum subcircular and ornamented, L 0.24, W 0.21. Ventral area between leg coxae I highly setose.

Remarks. MB.A.4458 ( Fig. 6 View FIGURE 6 ) can easily be identified as a member of the extinct genus Halitherses Giribet & Dunlop, 2005 , due to the presence of extremely large eyes dominating the prosoma ( Fig. 6A View FIGURE 6 ), slender legs and pedipalps, an ornamented carapace, and the absence of a pedipalp claw ( Fig. 6B, D View FIGURE 6 ). The specimen described herein is the smallest representative of the genus discovered so far and could, therefore, represent a juvenile. Nevertheless, for the first time a claw-like and curved apophysis can be observed proximally on the second cheliceral segment ( Fig. 6B–D View FIGURE 6 ) and is a significant observation as potential evidence for secondary sexual dimorphism (see Discussion).