Luberotenthredo cerestensis, Nel & Wei & Niu & Coster & Boderau & Josse & Kundura & Kundura & Brisac & Boudet & Jouault, 2024

Nel, André, Wei, Meicai, Niu, Gengyun, Coster, Pauline, Boderau, Mathieu, Josse, Hugo, Kundura, Jean-Paul, Kundura, Marie-Hélène, Brisac, Patrick, Boudet, Loup & Jouault, Corentin, 2024, The first sawfly from the Oligocene of Céreste (Southern France) (Hymenoptera: Tenthredinidae), European Journal of Taxonomy 917, pp. 1-18 : 4-8

Luberotenthredo cerestensis sp. nov.

urn:lsid:zoobank.org:act:C0B3232C-A6E4-4769-8830-1175B235

Figs 1–4

Diagnosis

As for the genus, by monotypy (vide supra).

Etymology

Named after the small village of Céreste (Luberon, Southern France).

Type material

Holotype

FRANCE • ♀ (imprint of a complete specimen fossilized in dorsal view); Alpes-de-Haute-Provence, South of the village of Céreste ; Early Oligocene, ‘ Calcaire de Campagne-Calavon’ Formation ; PNRL 2716 , stored in the Musée de Géologie, Réserve géologique du Luberon, Parc naturel régional du Luberon, Apt, France.

Type locality and horizon

France, Alpes-de-Haute-Provence, South of the village of Céreste, Early Oligocene, ‘Calcaire de Campagne-Calavon’ Formation.

Description

MEASUREMENTS. Body length 8.7 mm.

COLOR. Body brown with darker head; compound eyes dark brown; wings hyaline, pterostigma dark brown anteriorly and lighter posteriorly.

HEAD. Deformed and poorly preserved, 1.4 mm long, 2.0 mm wide; compound eyes large, occupying most of head lateral surface, deformed; mouthparts not preserved except left mandible with at least one apical and two preapical teeth; antennae very long, slightly longer than abdomen; scape and pedicel very short; seven flagellomeres; third antennomere as long as fourth; preapical flagellomeres cylindrical, elongate, slightly truncate obliquely.

THORAX. ca 3.0 mm long, 2.8 mm wide, apparently smooth (deformed by compression); pronotum markedly constricted medially; propleuron short and head close to thorax; legs not preserved.

FOREWING. Complete, 7.5 mm long, 2.9 mm wide; short anterior Sc branch located slightly anteriad Sc+R and 1-M meeting point; pterostigma 1.3 mm long, 0.5 mm wide, strongly arched along cell 2R1, slightly arched along anterior wing margin; M+Cu slightly curved; 1-M slightly longer than 1-Cu, nearly straight; vein R clearly deviated between junctions of 1-M and Sc; fusion of M with R very long, longer than half length of vein 1-M; vein 2-M meeting R more than halfway between short anterior Sc branch and pterostigma; vein 2-M slightly longer than 1rs-m; Rs emerging at pterostigmal base; 2-Rs nearly straight, longer than 3-Rs; r-rs crossvein located in pterostigma distalmost part, meeting Rs anteriad 3rsm, enclosing cell 2R1; 4-Rs and 5-Rs nearly aligned with 4-Rs extremely short (more than twice shorter than 3-Rs); cell 1R1 trapezoidal, 0.5 mm long; cell 1Rs 1.2 mm long, enclosed distally by subvertical 2rs-m (the latter lightly longer than 1rs-m); 3-M shorter than 4-M; cell 2Rs 0.9 mm long, distinctly wider along sinusoidal 3rs-m; 1-Cu and 2-Cu nearly straight, 1-Cu longer than 2-Cu; lm-cu meeting Cu at an angle of ca 110°, 1-M and 1m-cu subparallel and of similar lengths; cell 1Cu elongate, longer than cell R; 1cu-a (nervulus) located slightly distad middle of cell 1M; cell 2Cu short trapezoidal; cell 2M fully enclosed distally by long slightly sinusoidal crossvein 2m-cu; vein 1-A long, nearly straight; vein 2A+3-A complete, strongly sinuate in first half, fused with to 1-A on a short distance; cell 1A shorter than cell 2A, ca 0.8× length of cell 2A.

HIND WING. ca 6.3 mm long; thin costal cell present; thin space between C and R along anterior wing margin; M+Cu long, nearly straight, fork located anteriad Rs origin: 1M long, slightly arched, apparently meeting Rs (i.e., no rs-m crossvein present); abscissae of Rs distad meeting point with 1-M long and nearly straigth; cell R1 elongate and thin; cell Rs virtually fully enclosed (second abscissa of M difficult to interpret); crossvein 1rs-m located near middle of cell R1; cell 1M trapezoidal, rather broad, 1.4 times as long as wide; 1-Cu and 2-Cu of similar lengths, closed distally by 1m-cu; cell 1Cu elongate, rectangular, closed distally by cu-a; 1-A long slightly sinusoidal; crossvein a-a located at level of 1-M origin; 2-A long, slightly arched; cell 1A wider than 1Cu but shorter; vein 3-A present, short.

ABDOMEN (partly preserved). Without visible surface sculpture, virtually 4.5 mm long, 2.4 mm wide; ovipositor sheath short and broad, 0.8 mm long.

Remarks

The new fossil differs from the genus Sambia Vilhelmsen & Engel, 2012 (Eocene Baltic amber) in the forewing veins 2+3-A, which are fused with 1-A on a short distance (vs a long crossvein in-between) and its elongate flagellomeres ( Vilhelmsen & Engel 2012). With the lower Oligocene genus Nortonella Rohwer, 1908 it shares the vein 2+3-A shortly fused with 1-A ( Rohwer 1908: fig. 1). But Nortonella has the crossvein 1cu-a very close to the base of 1-M, versus about midway between the base of 1-M and 3-Cu in the new fossil and in several extant species of the genus Perineura Hartig, 1837 (see photographs of the holotype UCM 4517: https://invertpaleosearch.colorado.edu/). The new fossil can be separated from the lower Oligocene genus Taeniurites Cockerell, 1917 by the vein 2+3-A, which is shortly fused with 1-A (vs separated) and vein 1cu-a about midway between the base of 1-M and 3-Cu, vs very close to the base of 1-M ( Cockerell 1917). The Uppermost Oligocene genus Tenthredinites Meunier, 1915 is based on a poorly preserved specimen ( Meunier 1915), which is probably lost. Rodriguez et al. (2017) suggested it could be a Pompilidae Latreille, 1805 . The Miocene genus Tenthredoides Zhang, 1989 differs from the new fossil in the vein 1cu-a, which is very close to the base of 1-M ( Zhang 1989: textfig. 224).

Figures

Fig. 1. Luberotenthredo cerestensis gen. et sp. nov., holotype (PNRL 2716). Photograph of habitus. Scale bar = 2 mm.

Fig. 2. Luberotenthredo cerestensis gen. et sp. nov., holotype (PNRL 2716). Photographs. A. Right wings. B. Left wings. Scale bars = 2 mm.

Fig. 3. Luberotenthredo cerestensis gen. et sp. nov., holotype (PNRL 2716). Photographs. A. Head and thorax. B. Head and antenna. C. Reconstruction of antenna. D. Apex of abdomen. Scale bars = 1 mm.

Fig. 4. Luberotenthredo cerestensis gen. et sp. nov., holotype (PNRL 2716). Reconstructions of the wing venations with names of cells and veins labeled. Scale bar = 1 mm.