Paleosisyra eocenica, Nel & Menier & Waller & Hodebert & Ploëg, 2003

Nel, André, Menier, Jean-Jacques, Waller, Alain, Hodebert, Gilbert & Ploëg, Gaël De, 2003, New fossil spongilla-flies from the lowermost Eocene amber of France (Insecta, Neuroptera, Sisyridae), Geodiversitas 25 (1), pp. 109-117 : 111-114

Paleosisyra eocenica n. sp. ( Figs 1-8 )

TYPE MATERIAL. — Holotype male specimen PA 2789 (1/8), with eight adult Diptera : Chironomidae and a Ephemeroptera in the same piece of amber. Female allotype specimen PA 156 (1/2), female paratype specimens PA 11, PA 52 (1/5), PA 157 (1/5), PA 2329, PA 2478 (1/2) and (2/2), PA 2493 (1/2), PA 2812, PA 3921, PA 4144, PA 4864, PA 5368, PA 5374, PA 5603. All specimens in collection De Ploëg and Indivision Langlois-Meurine, deposited in Muséum national d’Histoire naturelle, Paris. Specimens collect- ed in Le Quesnoy all bear the letter PA for Paris (meaning Paris basin); the following number is the ordinal number in the collection.

ETYMOLOGY. — After the age of the amber locality.

TYPE LOCALITY. — Le Quesnoy, Chevrière, region of Creil, Oise department, France.

GEOLOGICAL AGE. — Lowermost Eocene, Sparnacian, level MP 7 of the mammal fauna of Dormaal. We could demonstrate that the amber is autochthonous and very different from the Baltic amber in age, chemical composition and origin ( Nel et al. 1999).

STATE OF PRESERVATION OF THE MATERIAL. — Specimen PA 2789 (1/8): nearly complete in a very clear piece of amber. The upper surfaces of the thorax and abdomen are partly destroyed. Specimen PA 156 (1/2): complete in a very clear piece of amber, together with a small insect. Specimens PA 11, PA 2478 (1/2 and 2/2), PA 2493 (1/2), PA 2812, PA 5368, and PA 5603: complete in very clear pieces of amber. Specimen PA 2329: complete covered with pollen. Specimens PA 157 (1/5), PA 4144, PA 4864, and PA 5374: head and thorax partly destroyed. Specimen PA 3921: apical parts of four wings.

DESCRIPTION

It is based on all specimens. The characters only visible on one specimen are indicated.

Head

Antenna with 36 segments, two whorls of setae on all but the basal segment, on which the setae are irregularly arranged; basal antennal segment larger than the others; clypeus and labrum not clearly visible; maxillary palpi with first, second and fourth segments shorter than the third, which is about one time and a half as long, terminal segment triangular in dorsal view, twice as long as the third, broadest at base, narrowed and tapered to a point at apex ( Fig. 7 ); labium not visible, except for labial palpi, with third terminal segment greatly enlarged, flattened, triangle shaped and very wide at base, the second small and subcylindrical, the first one time and a half the length of the second, and narrowed proximally; clypeus and labrum with anterior margins almost straight; labrum about three times as broad as long (visible on specimen PA 156, 1/2).

Thorax

Pronotum with a strong median furrow, laterally extended but not overlapping the cervicales and dorsal portion of pleural sclerites; laterocervicales (sensu Parfin & Gurney 1956) large and prominent; prothoracic epimeron and episternum well defined and broad, with a furrow between them, unlike in extant Sisyra and Climacia , in which these sclerites are “reduced and united to almost form a single plate” ( Parfin & Gurney 1956); numerous long and strong setae on pronotum and pleural sclerites; caudal indentation of posterior margin of metepimeron weak, less pronounced than in Sisyra (visible on specimen PA 157, 1/5); mesonotum with scutellum having a broad apex, similar to that of Sisyra (visible on specimen PA 2493, 1/2); metanotum and metascutellum not visible, hidden under the hindwings.

Legs

Metathoracic pair longer than meso- and prothoracic pairs; coxae and trochanter similar to those of extant Sisyridae ( Parfin & Gurney 1956) ; two spurs on prothoracic leg, disposed one in front of the other; two spurs on mesothoracic and metathoracic legs, one beside the other; tarsi fivesegmented; the metatarsus the longest, the fourth the shortest; the fifth bearing a pair of curved, simple claws, with a broad ventral empodium between, as for extant Sisyridae .

Forewing ( Fig. 3 )

Length 5.2 mm; width 2.0 mm; membrane hyaline, with pterostigma slightly darker; costal area widened 1.4 mm distal of wing base, 0.4 mm wide at widest point and 0.2 mm wide at narrowest point; costal cross-veins all simple, numerous, about 26 before pterostigma and 14 in the pterostigma before the apical fusion between Sc and R; subcostal area between Sc and R, 0.2 mm wide; only one basal subcostal cross-vein, below the fourth costal cross-vein; Sc and R clearly coalescent at apex of wing below the pterostigma; RP + MA separating off from R 0.8 mm from base; RP separating from MA 0.2 mm distally; basal of the first cross-vein (1 st r sensu Parfin & Gurney 1956) between R and RP; three crossveins in the area between R and RP; the first basal fork of RP is just basal of 1 st r, only at the 27% of the wing length, instead of 40% in Sisyra vicaria (Walker, 1853) and 70% in Climacia areolaris (Hagen, 1861) ; a cross-vein aligned with the 1 st r between MA and first posterior branch of RP; distance between the first and the second fork of RP 1.2 mm, longer than in Sisyra ); the second fork of RP is at the 50% of the wing length and the third fork slightly distally, at the 60% of the wing length; MA divided into two branches 0.6 mm basal of level of junction between Sc and R; MP forking into two branches 0.5 mm distal of separation of RP and MA, below the first fork of RP; the two branches of MP with terminal forks basal of level of junction between Sc and R; CuA and CuP separated 0.7 mm from wing base; CuA with four main branches, organized in two groups, not parallel and of different length; CuP simple; A1 with one marginal forking; A2 simple; A3 distally fused with A2, not running to anal margin (specimen PA 156, 1/2); three radiomedial cross-veins between RP and MA; two medial cross-veins between MA and MP; two medio-cubital cross-veins between MP and CuA; one cubital cross-vein between CuA and CuP; one cubito-anal cross-vein between CuP and A1; one anal cross-vein between A1 and A2; one inner series of three gradate cross-veins, not exactly aligned with 2 nd r; one outer series of five gradate cross-veins, included the 3 rd r.

Hindwing ( Figs 4-6 )

Length 3.9 mm; width 1.9 mm; membrane hyaline, with pterostigma slightly darker; costal area not widened, 0.1 mm wide at widest point; costal cross-veins all simple, numerous, about 18 before pterostigma and eight in the pterostigma before the apical fusion of Sc and R; subcostal area between Sc and R, 0.6 mm wide; no basal subcostal cross-vein; Sc and R clearly coalescent at apex of wing below the pterostigma; RP separating off from R 0.7 mm from base; MA separating off from MP 0.2 mm from base of M and fused with RP 0.7 mm distally; MA and RP are fused for a very short distance, MA separating from RP again 0.03 mm distally, 0.4 mm basal of first cross-vein (1 st m sensu Parfin & Gurney 1956) between MA and MP; cross-vein 1 st r between R and RP well distal (0.4 mm) of first basal fork of RP, and about 0.2 mm distal of level of 1 st m; two cross-veins in the area between R and RP; cross-vein 2 nd r just distal of the point of coalescence of Sc and R; distance between the first and the second fork of RP, 0.3 mm; MP forking basal of point of separation of RP from MA; costal

R Sc

CuP CuA

RP MA MA

CuP

branch of MP with terminal fork basal of level of point of coalescence of Sc and R; CuA and CuP separating near base of wing; CuA long parallel to posterior wing margin, with seven or eight simple parallel posterior branches; CuP simple; A1 simple or with a short marginal fork; A2 simple; one series of seven outer scalariform cross-veins; two cross-veins between MA and MP; one crossvein between the two branches of MP, one between MP and CuA, one between CuA and CuP, one between CuP and A1, and one between A1 and A2.

Abdomen

Second and third tergites not sclerotized, appearing as rows of setae; fourth to seventh sclerotized, but small oval; second sternite large, with V-shaped streak; third sternite smaller, rectangular; sternites fourth to seventh also rectangular but smaller than third.

Male genital appendages (specimen PA 2789) ( Fig. 8 )

They are rather poorly preserved. Eighth and ninth tergites not well preserved; ectoprocte (epr sensu Aspöck et al. 1980) entire, broader than long; ninth sternite large and appearing terminal ventrally, but with no posterior processes; a pair of long movable heavily sclerotized coxopodites (cp sensu Aspöck et al. 1980), furnished with setae and denticles in their inner side; parameres very small compared to claspers, hidden under the ectoprocte.

Female genital appendages

Ninth tergite and ectoprocte (epr) as in Fig. 8 ; gl long and narrow, with the apex strongly curved.

Figures

FIG. 1. — Paleosisyra eocenica n. gen., n. sp., specimen PA 2478 (1/2). Scale bar: 1 mm.

FIG. 7. — Paleosisyra eocenica n. gen., n. sp., specimen PA 2478 (1/2), labial and maxillary palpi. Scale bar: 0.1 mm.

FIG. 3. — Paleosisyra eocenica n. gen., n. sp., specimen PA 2478 (1/2), forewing. Abbreviations: CuA, cubitus anterior; CuP, cubitus posterior; MA, media anterior; MP, media posterior; R, radial vein; RP, radius posterior; Sc, subcosta. Scale bar: 1 mm.

FIG. 4. — Paleosisyra eocenica n. gen., n. sp., specimen PA 2478 (1/2), left hindwing, area of the bases of M and RP. Abbreviations: MA, media anterior; RP, radius posterior. Scale bar: 0.5 mm.

FIG. 5. — Paleosisyra eocenica n. gen., n. sp., specimen PA 2478 (1/2), posterior part of right hindwing. Abbreviations: CuA, cubitus anterior; CuP, cubitus posterior; MA, media anterior. Scale bar: 0.5 mm.

FIG. 6. — Paleosisyra eocenica n. gen., n. sp., specimen PA 2478 (1/2), left hindwing in dorsal view. Abbreviation: RP, radius posterior. Scale bar: 0.5 mm.

FIG. 8. — Paleosisyra eocenica n. gen., n. sp., male genital appendages of specimen PA 2789 and female genital appendages of specimen PA 2478 (1/2). Abbreviations: cp, coxopodite; epr, ectoprocte (after Aspöck et al. 1980); gl, lateral gonapophyses; T9, 9th tergite. Scale bar: 0.5 mm.