Two new fossil wasps (Insecta: Hymenoptera: Apocrita) from northeastern China

Praeaulacus obtutus sp. nov., assigned to the subfamily of Praeaulacinae Rasnitsyn, 1972 in the family Praeaulacidae, Rasnitsyn, 1972, and Proapocritus bialatus sp. nov., in the family Ephialtitidae, are described and illustrated. These specimens were collected from the Middle Jurassic of Jiulongshan Formation at Daohugou in Inner Mongolia, northeastern China. Praeaulacus obtutus sp. nov. was erected by a combination of differential characters: the short and stout mesosoma, pronotum comparatively long, mesonotum not very long, the combination of pronotum and mesonotum transversely ridged and nearly arched; long hind legs. Proapocritus bialatus sp. nov. is assigned to Proapocritus Rasnitsyn, 1975 due to the following characters: wings venation complete, forewing with 1-Rs directed slightly posterodistally; 1r-rs, 2r-m, 3r-m, 2m-cu, 2A and a1-a2 present; hind wing with enclosed cell; Rs originating not basad of M + Cu fork. These findings provide new characters of these two groups and broaden the diversity of Praeaulacus and Proapocritus. http://zoobank.org/urn:lsid:zoobank.org:pub:BBC9B0D6-7E07-4A26-A975-21FFAEADE8B6

Introduction was erected from a hymenopteran forewing from the Early or Middle Jurassic Kyrgyzstan. Until 2010, other characteristics of this genus were based on the new and complete specimens from Daohugou village, China (Rasnitsyn and Zhang 2010).
Herein, we describe two new fossil wasps, Praeaulacus obtutus sp. nov. of Praeaulacidae and Proapocritus bialatus sp. nov. of Ephialtitidae, both of which were collected from the Jiulongshan Formation at Daohugou village, Ningcheng County, Inner Mongolia, China.

Material and methods
All the specimens were collected from the Jiulongshan Formation at Daohugou, Ningcheng County, Inner Mongolia, China. The type specimens are deposited in the Key Laboratory of Insect Evolution & Environmental Changes, Capital Normal University, Beijing, China (CNU).
These specimens were examined under a Leica MZ 12.5 dissecting microscope and illustrated with the aid of a camera lucida attached to the microscope. The figures were drawn with Adobe Photoshop CS5 and CorelDraw 12.0. Wing venation terminology is adapted from Zhang and Rasnitsyn (2008) and Rasnitsyn and Zhang (2010).

Etymology
The specific epithet is derived from the Latin word obtutus (contemplation), indicating the posture of this wasp.

Diagnosis
Antenna longer than mesosoma. Mesosoma short and stout; pronotum comparatively long; mesonotum not very long, combination of pronotum and mesonotum transversely ridged and nearly arched. Forewing with first abscissa of Rs (1-Rs) shorter than its distance to pterostigma; 2r-rs meeting Rs basad of 2r-m and slightly shorter than the maximal width of 2rm; 3rm shorter than 2rm, with 3r-m bending; 2rm in contact with 1mcu by a short section of M; cu-a interstitial. Hind wing with M and Cu possessing free ends; cu-a strongly oblique, meeting Cu distad of M + Cu fork. Hind legs very long.

Description
A wasp in lateral view; body and wings well preserved; forewing, hind wing and metasoma partially overlapping, but the venation mostly discernible with alcohol ( Figure 1C). Body 6.2 mm long; head medium-sized, 0.9 mm long and 1.2 mm high, with large eyes and irregular oval-shape; antenna, longer than mesosoma, with 16 antennomeres, as preserved and 2.5 mm long ( Figure 1A, B); mesosoma stout, 1.9 mm long and 2.0 mm high (Figure 1 D, E); pronotum, mesonotum, mesoscutellum, metanotum, propodeum, mesopleuron and hind coxa are clearly discernible (Figure 1 D, E); the pronotum comparatively long; mesonotum not very long, the combine of pronotum and mesonotum transversely ridged and nearly arched; the mesoscutellum nearly as long and wide as metanotum; propodeum short, but broad in profile aspect; metasoma is 3.6 mm long with first segment petiole-like (0.8 mm long and 0.5 mm maximal width); propodeal foramen attached high on propodeum and much closer to metanotum than to hind coxa; hind legs very long, the lengths (in mm) of hind leg, coxa, trochanter, femur, tibia and the 1st to 5th tarsus: 0.7: 0.3: 1.4: 2.3: 0.4: 0.4: 0.2: 0.2 (Figure 1 A).
Forewing 3.8 mm long and 1.6 mm wide, with first abscissa of Rs (1-Rs) shorter than that of M (1-M), also shorter than its distance to pterostigma, measurements (in mm) of 1-Rs, 1-M, and the distance from 1-Rs to pterostigma about 0.2: 0.3: 0.5; vein 2r-rs arising from pterostigma about its basal one-half length, slightly shorter than the maximal width of cell 2rm and meeting Rs considerably basad of 2r-m; vein 2r-m nearly straight and 3r-m slightly bending; cell 2rm longer than 3rm, the latter wider than 2rm; cell 1mcu nearly parallelogrammic, about twice as long as wide; vein 2m-cu meeting 3rm at one-fifth of its posterior margin; cell 2mcu 1.5 times as broad as 1mcu and 1.4 times as long as 1mcu; vein cu-a interstitial and longer than 1-M, 2cu-a about half as long as cu-a.
Hind wing 1.3 mm long and 1.1 mm wide as preserved, with r-m straight and about 0.7 times as long as 1-Rs; the first section of M (1-M) nearly straight, 2.5 times as long as r-m; vein cu-a strongly oblique, meeting Cu beyond the forking of M + Cu into M and Cu; anal vein A present.

Remarks
Praeaulacus obtutus sp. nov. is assigned to Praeaulacidae based on a combination of forewing and body characters: medial mesonotal suture well developed, forewing venation with most of the main veins and metasoma attached high. It is attributed to Praeaulacinae based on several characters: antenna with more than 15 antennomeres, mesonotum transversely ridged, forewing with 2r-m, 3r-m and 2m-cu present, cu-a interstitial, and 1r-rs and 2A absent, hind wing with R strong and reaching apex of Rs. Praeaulacidae is a paraphyletic group in respect to the other Evanioidea. All the clade of Evanioidea is synapomorphic in having upper attachment of metasoma on the propodeum, which is closed below the attachment foramen. Praeaulacidae other than Nevaniinae are synapomorphic in lost 2A vein and a1-a2 crossvein, Nevaniinae is synapomorphic in having two-segmented petiole, but Praeaulacidae as a whole has no synapomorphies.
Praeaulacus obtutus sp. nov. differs from other species of Praeaulacus by the following characters: mesosoma short and stout, nearly as long as high; pronotum comparatively long; mesonotum slightly shorter than pronotum and legs very long; forewing with first abscissa of Rs (1-Rs) shorter than its distance to pterostigma, 2r-rs slightly shorter than the maximal width of 2rm.

Etymology
The specific epithet is derived from the Latin word bialatus (a pair of wings), indicating the well-preserved and out-stretched wings.

Diagnosis
Antenna slim, with more than 25 segments. Forewing with cu-a slightly postfurcal, 1r-rs vein reduced near R and pterostigma, 2r-m, 3r-m slightly bent (not vertical); 2mcu wavy curved; hind wing with 1-Rs originating not basad of M + Cu fork, 1-M and cu-a nearly parallel. First metasomal segment nearly trapezoid.

Description
Female wasp in dorsal view; left and right wings well preserved with main veins clearly discernible ( Figure 3A, B). Body 15.8 mm long including the antennae and ovipositor (body 9.6 mm long excluding the antennae and ovipositor); the head transversely broad, about 0.9 mm long and 1.8 mm wide; antenna thin and well preserved, with 25 antennomeres and about 5.4 mm long, pedicel short and slightly narrower than distal part of the scape, flagellomeres equal in length and width; mesosoma long and slender, about 3.1 mm long and 1.9 mm wide; pronotum, mesonotum, mesoscutellum, metanotum, metascutellum and propodeum discernible ( Figure 3A, B); the mesonotum with notauli nearly V-shaped and reaching transscutal suture; mesoscutellum slightly wider and longer than metanotum; propodeum longer than metanotum; metasoma 5.5 mm long excluding the ovipositor, with six segments visible, the first metasomal segment nearly trapezoid, apical part about 1.5 times as wide as basal part. Ovipositor 5.2 mm long with sheaths; legs partially preserved and the hind legs longer and wider than the forelegs and mid legs.
Forewing 6.7 mm long and 2.1 mm wide as preserved, with pterostigma long and acuminate, issuing 2r-rs at its mid-length ( Figure 3A, B); the first abscissa of Rs (1-Rs, 0.3 mm long) subvertical to R and slightly shorter than that of M (1-M, 0.4 mm long); vein 1r-rs present but reduced near R and pterostigma, and the distance of 1r-rs to Rs base longer than that to 2r-rs base; vein 2r-rs slightly longer than the width of pterostigma and nearly as long as the maximal width of cell 2rm, and about half the length of 2rm, and subparallel to 1r-rs and 1-Rs; cell 1mcu nearly parallelogrammic, about 2.5 times as long as wide; vein 1m-cu (0.4 mm long) meeting 2rm slightly beyond Rs + M forking and slightly shorter than cu-a (0.5 mm long); vein cu-a slightly postfurcal, parallel to a 1 -a 2 and 1.6 times as long as a 1 -a 2 ; vein 2m-cu bending and 1.5 times as long as 1m-cu; vein 2A completely preserved.
Hind wing 3.6 mm long and 1.5 mm wide as preserved, distinguishable with 1-Rs origin at the same level of M + Cu forking; cell r closed; vein r-m straight and 0.6 times as long as 1-Rs; the first abscissa of M (1-M) slightly arched and about three times as long as r-m; vein cu-a long and strongly oblique, meeting Cu beyond M + Cu forking; vein A present, free M and Cu long.

Remarks and comparison
The genus Proapocritus, 1975 was erected by a hymenopteran forewing from the Early or Middle Jurassic Kyrgyzstan, and tentatively placed in Karatavitidae (Karatavitidae was considered to be the most primitive apocritans). Proapocritus was considered to almost completely cover the hiatus between Karatavites of Symphyta and Ephialtitidae of Apocrita (Rasnitsyn 1975 Proapocritus bialatus sp. nov. is assigned to to Proapocritus Rasnitsyn, 1975 because of the following characters: wings with complete venation, forewing with 1-Rs directed slightly posterodistally; 1r-rs, 2r-m, 3r-m, 2m-cu, 2A and a 1 -a 2 present; hind wing with enclosed cell r; Rs originating not basad of M + Cu fork and so on. This new species differs from other species (except Proapocritus densipediculus) of the genus Proapocritus in the forewing with cu-a slightly postfurcal (versus other species of the genus with cu-a intersitial); differs from Proapocritus densipediculus in forewing with 2r-m, 3r-m slightly bend and 2m-cu wavy curved and the first metasomal segment nearly trapezoid (versus Proapocritus densipediculus with 2r-m, 3r-m vertical while 2m-cu not preserved, and the first metasomal segment as wide as propodeal foramen, subcylindrical).

Discussion
Praeaulacid wasps were widely distributed during the Mesozoic of Australia and Asia (e.g. Rasnitsyn 1972Rasnitsyn , 1990aRasnitsyn , 1990bJell and Duncan 1986). As aforementioned, Praeaulacus obtutus sp. nov. has interesting and special body characters, which can be distinguished from other known wasps in Praeaulacinae: short and stout mesosoma, the combination of pronotum and mesonotum transversely ridged and nearly arched, and long legs. However, Praeaulacus obtutus sp. nov. with the metasoma attaching high and much closer to metanotum than to hind coxa, is similar to those known in other subfamilies of Praeaulacidae. Grimaldi and Engel (2005) mentioned that evanioid wasps shared a distinctive trait that the the metasoma is connected with the propodeum, and the earliest evidence of evanioids was found in the extinct family Praeaulacidae. Praeaulacidae shares many characters with other evanioids, e.g. the dorsal propodeal articulation with the metasoma, but is otherwise primitive in other features (e.g. wing venation with moderately more main veins), perhaps representing a stem group to the remaining groups in the superfamily (Grimaldi and Engel 2005). This well-preserved new material from Daohugou not only shows the typical propodeal-metasomal articulation, but also broadens the diversity of Praeaulacinae.
To date, seven species, including this new species, have been reported within Proapocritus Rasnitsyn, 1975 in the literature. Except for the type species Proapocritus praecuesor Rasnitsyn, 1975 from the Early or Middle Jurassic Kyrgyzstan, other species are all from the Middle Jurassic Jiulongshan Formation at Daohugou Village of China. New and complete material from Daohugou shows that this genus is uniform in wing venation and propodeum but diverse in the form of the first metasomal segment. So, Proapocritus bialatus sp. nov. described in this paper can expand our knowledge of the ephialtitid propodeal-metasomal articulation after the highly diverse patterns of propodeal-metasomal articulation observed in Proapocritus (Rasnitsyn and Zhang 2010).
Journal of Natural History 837