Cenotextricella simoni Penney

Penney, David, Dierick, Manuel, Cnudde, Veerle, Masschaele, Bert, Vlassenbroeck, Jelle, Hoorebeke, Luc Van & Jacobs, Patric, 2007, First fossil Micropholcommatidae (Araneae), imaged in Eocene Paris amber using X-Ray Computed Tomography, Zootaxa 1623, pp. 47-53 : 49

Cenotextricella simoni Penney sp. nov.

Figs 1–12

Type material. Holotype male: in lowermost Eocene amber from the Paris Basin ( MNHN PA 327).

Etymology. The specific epithet is a patronym in honour of the famous French arachnologist Eugene Simon.

Diagnosis. As for the genus.

Description. Male holotype. Body length 1.08 mm. Carapace elevated in the cephalic region, bearing eight eyes; anterior medians smallest and contiguous, remainder subequal; lateral eyes contiguous and not on a raised mound, posterior medians slightly separated ( Figs 1, 3, 6 ). Sternum as wide as long, evenly rounded posteriorly, coxae 4 clearly separated ( Fig. 2 ). Labium three times wider than long, unnotched; endites directed across labium but do not meet in the midline. Chelicerae vertical, not fused along their length and with promarginal dentition ( Figs 2, 3, 6 ). Abdomen ovoid, with a large dorsal scutum (with sparse but distinct setae, not detected by the VHR-CT) and a ventral scutum in the epigastric region surrounding the pedicel ( Figs 1, 2, 4–6 ). Relative order of leg length 1,2,4,3, with distinctly shortened metatarsi (0.5 × tarsi length) on all legs ( Figs 1–5 ). Legs with erect, bristle-like setae (not picked up by the VHR-CT) as follows: one distal on each patella, one proximal on each tibia, one distal on tibiae 1, 2 and 4 ( Figs 11, 12 ). Spinnerets situated posteriorly in a compact group, with a distinct colulus ( Figs 2, 4, 5 ). Pedipalp ( Figs 6–10 ) with embolus wrapped around a conductor ( Figs 6, 9 ); tibia complex, flattened and abutting on the cymbium, with broad prolateral extension ( Fig. 8 ) and a distinct tibial hook visible in retrolateral view ( Fig. 9 ); patella with a proximal, retrolateral knob-like projection ( Figs. 6, 9 ).

Distribution: Early Tertiary (lowermost Eocene) Paris Basin amber forest.

Figures

FIGURES 1 – 10. VHR-CT scans of Cenotextricella simoni sp. nov. (male holotype, MNHN PA 327). (1) dorsal view; (2) ventral view; (3) anterior view; (4) posterior view; (5) lateral view; (6) lateral sectioned view; (7) right pedipalp dorsal view; (8) right pedipalp posterior view; (9) left pedipalp retrolateral view; (10) right pedipalp prolateral view. Abbreviations: ALE, anterior lateral eye; AME, anterior median eye; c, conductor; cy, cymbium; ds, dorsal abdominal scutum; e, embolus; fe, femur; mt / t, metatarsus / tarsus joint; pa, patella; PLE, posterior lateral eye; PME, posterior median eye; st, sternum; th, tibial hook; ti, tibia; vs, ventral abdominal scutum.

FIGURES 11 – 12. Photographs of Cenotextricella simoni sp. nov. (male holotype, MNHN PA 327) using traditional light microscopy. (1) dorsal view; (2) ventral view. See Fig. 5 for scale.