Foveacorpus cretaceus, Bartel & Dunlop & Giribet, 2023

Bartel, Christian, Dunlop, Jason A. & Giribet, Gonzalo, 2023, An unexpected diversity of Cyphophthalmi (Arachnida: Opiliones) in Upper Cretaceous Burmese amber, Zootaxa 5296 (3), pp. 421-445 : 435

Species Foveacorpus cretaceus sp. nov.

Figs. 11–12

urn:lsid:zoobank.org:act:D76311F9-33F8-4734-8C4F-30F02D17D35D

Holotype. Specimen GPIH05129 , ex coll. Patrick Müller, BUB3645.

Type-locality. Myanmar, Hukawng Valley; Burmese amber, Upper Cretaceous (Lower Cenomanian).

Etymology. The specific epithet “cretaceus” (a Latin adjective) refers to the Cretaceous Period.

Diagnosis. Distinct from Foveacorpus parvus sp. nov. in more oval body, larger body size (more than 1 mm), larger pits in the tegument and less bulbous ozophores.

Description. Body oval, somewhat subtriangular in profile at anterior end and completely covered with small pits (their diameter 0.016*); total L 1.03, maximum prosomal W behind ozophores 0.39, maximum opisthosomal W 0.45. Dorsal tergites without visible sutures ( Fig. 11A, C ). Rounded ozophores covered with small pits and probably in type 1 position. L of ozophores 0.07, W at base 0.09, distance between bases of ozophores 0.24. Eyes equivocal. Chelicerae moderately long, protruding and finely granular; fingers thin and relatively long, somewhat overlapped by thicker setae originating from coxae I ( Fig. 12A ); dentition equivocal; basal segment L 0.19, median segment L 0.25, distal segment L 0.09. Pedipalps small and granular on femur; tarsus covered with sensory setae and bearing a small claw on its tip; pedipalp length: tr?, fe?, pa 0.07, ti 0.09, ta 0.08*. Legs relatively short, robust and granular; legs I and II are notably forward-directed and leg IV relatively far away from leg III; left leg III (in ventral view) appearing modified, more robust and with scopula on tarsus as compared to right leg III; leg tarsi not subdivided, each bearing a single smooth claw and numerous setae (sensory setae and thick setae); tarsus IV without adenostyle; leg lengths: I, tr 0.07, fe 0.18, pa 0.10, ti 0.15, mt 0.08, ta 0.08, total 0.66; II tr 0.07, fe 0.12, pa 0.09, ti 0.13, mt 0.13, ta 0.13, total 0.67; III tr 0.08, fe 0.12, pa 0.05, ti 0.09, mt 0.10, ta 0.08, total 0.52; IV tr 0.07, fe 0.13*, pa 0.09, ti 0.13, mt 0.07, ta 0.07, total 0.56. Ventral side of opisthosoma also covered with numerous small pits. Gonostome open and somewhat circular, surrounded with few thick setae, W 0.07, L 0.07. Possible spiracles indicated by a few circularly arranged denticles situated posterior to coxae IV. Anal plate rounded, with few small pits and surrounded by a corona analis, W 0.10, L 0.08 ( Fig. 12B ).

Figures

FIGURE 11. Foveacorpus cretaceus gen. et sp. nov., female holotype (GPIH05129). A. Whole body, dorsal view. B. Same, ventral view. C. Camera lucida drawing of A. D. Same of B. Abbreviations: ca, corona analis; ch, chelicerae; oz, ozophore; pp, pedipalp; legs numbered from I–IV. Scale bars equal 0.5 mm.

FIGURE 12. Details of Foveacorpus cretaceus gen. et sp. nov., female holotype (GPIH05129). A. Close-up of chelicerae, pedipalps and gonostome (indicated by arrows), ventral view. B. Close-up of opisthosoma, ventral view. Abbreviations: ca, corona analis; ch, chelicerae; go, gonostome; pp, pedipalp; oz, ozophore; legs II, III and IV numbered. Scale bars equal 0.2 mm.