New and revised maimetshid wasps from Cretaceous ambers (Hymenoptera, Maimetshidae)

Abstract New material of the wasp family Maimetshidae (Apocrita) is presented from four Cretaceous amber deposits – the Neocomian of Lebanon, the Early Albian of Spain, the latest Albian/earliest Cenomanian of France, and the Campanian of Canada. The new record from Canadian Cretaceous amber extends the temporal and paleogeographical range of the family. New material from France is assignable to Guyotemaimetsha enigmatica Perrichot et al. including the first females for the species, while a series of males and females from Spain are described and figured as Iberomaimetsha Ortega-Blanco, Perrichot & Engel, gen. n., with the two new species Iberomaimetsha rasnitsyni Ortega-Blanco, Perrichot & Engel, sp. n. and Iberomaimetsha nihtmara Ortega-Blanco, Delclòs & Engel, sp. n.; a single female from Lebanon is described and figured as Ahiromaimetsha najlae Perrichot, Azar, Nel & Engel, gen. et sp. n., and a single male from Canada is described and figured as Ahstemiam cellula McKellar & Engel, gen. et sp. n. The taxa are compared with other maimetshids, a key to genera and species is given, and brief comments made on the family.


Dedication
We lovingly dedicate this humble contribution to the discoverer of the Maimetshidae, our friend and colleague, Prof. Alexandr P. Rasnitsyn, on the occasion of his 75 th birthday. It is greatly hoped that Alex, as the great docent of hymenopterological paleontology, will look upon our work with favor and pride, knowing that his rich body of inquiry has inspired every aspect of our own probes into the history of this fascinating order.

introduction
The family Maimetshidae was established as an extinct lineage of apocritan wasps based on a single incomplete female and male preserved in Santonian Taimyr amber (Rasnitsyn 1975). A single genus and species, Maimetsha arctica Rasnitsyn, was recognized and considered to be intermediate between Megalyridae and Ceraphronoidea, linking these otherwise disparate groups (Rasnitsyn 1975(Rasnitsyn , 2002. More than a quarter century later, Perrichot et al. (2004a) described a second genus and species which shared considerable similarities with Maimetsha Rasnitsyn and Cretogonalys Rasnitsyn, a genus originally attributed to Trigonalyidae but subsequently recognized as a possible maimetshid (Rasnitsyn and Brothers 2009). Given the uncertainties of the time, Guyotemaimetsha Perrichot et al. was considered as family incertae sedis (Perrichot et al. 2004a). Later, Perrichot (2009) reported new specimens of Guyotemaimetsha as well as undescribed material from Spanish amber, all of which appeared to suggest closer affinities with Trigonalyidae [This name often appears as Trigonalidae, given that Cresson (1887) first used this spelling. However, ICZN (1999: Art. 29.3) dictates that the name is to be based on the correct stem by deleting the case ending of the genitive singular, in the present case giving "Trigonalyd-", thus the name would be automatically corrected to Trigonalydidae, with the same author and date, except that (Art. 29.3.1.1) notes that the unelided form, Trigonalyidae, is to be retained since the elided form (Trigonalydidae) is not in prevailing usage. Accordingly, Trigonalidae is a nomen imperfectum, which is recte Trigonalyidae Cresson, 1887].
The classification of Maimetshidae has been controversial, with various alternative interpretations of their putative relationships. For example, many authors have recognized them as an extinct, isolated family of Ceraphronoidea s.l. (Rasnitsyn 1975(Rasnitsyn , 1977(Rasnitsyn , 1988Ronquist et al. 1999;Rasnitsyn and Brothers 2009;Perrichot 2009;Ortega-Blanco et al. 2010), while Shaw (1988Shaw ( , 1990) considered them as a basal clade within the Megalyridae. Vilhelmsen et al. (2010a) provided the first critical phylogenetic evaluation for the group, recognizing Maimetshidae as sister to Trigonalyidae, uniting these two by at least asymmetrical mandibles (not observed in all maimetshids) and the tarsal plantulae in females. Maimetshidae differ from Trigonalyidae, however, at least by the ovipositor exserted (instead of concealed in Trigonalyidae: vide Oeser 1962) and the absence of antennal tyloids (these are present in all trigonalyids except the primitive genus Orthogonalys Schulz: vide Carmean and Kimsey 1998). While the relationship between Maimetshidae and Trigonalyidae now seems well corroborated, the classification of these within an expanded Ceraphronoidea (or Stephanoidea sensu Rasnitsyn and Brothers 2009 = Stephanidae, Megalyridae, Trigonalyidae, Maimetshidae, Ceraphronidae, Megaspilidae, Stigmaphronidae, and Radiophronidae) is not well supported, and the phylogenetic placement of Ceraphronoidea s.str. (= Ceraphronidae, Megaspilidae, Stigmaphronidae, and Radiophronidae) is debatable, although many higher-level analyses do recover them as part of the Evaniomorpha (Sharkey 2007;Davis et al. 2010;Vilhelmsen et al. 2010b;Rasnitsyn and Zhang 2010) rather than Proctotrupomorpha (Ronquist et al. 1999;Sharkey and Roy 2002). Most recently Heraty et al. (2011) failed to recover a monophyletic Evaniomorpha, although ceraphronoids did not group with Proctotrupomorpha, but their analysis also had Orussidae nested within a paraphyletic evaniomorph grade which is certainly controversial.
Herein we provide a systematic overview of new material of maimetshids in Cretaceous amber, including the descriptions of three new genera and four new species.

Material and methods
The species discussed herein were recovered from four different Cretaceous deposits, two in southwestern Europe (France and Spain), one in western Asia (Lebanon), and the last from northcentral North America (Canada). Details of each are briefly summarized below and more thorough discussions on their stratigraphy, paleoecology, and paleoenvironment can be found in Perrichot et al. (2010), Peñalver and Delclòs (2010), Azar et al. (2010), andWolfe (2010), respectively. Morphological terminology generally follows that used elsewhere in the Hymenoptera (e.g., Goulet and Huber 1993), and for consistency the wing terminology as applied in Perrichot et al. (2004a). Acronyms for the institutions with collections studied herein are as follows: MNHN, Muséum National d'Histoire Naturelle, Paris, France; IGR, Géosciences Rennes, Université Rennes 1, Rennes, France; MCNA, Museo de Ciencias Naturales de Álava, Vitoria-Gasteiz, Spain; and CNC-CAS, Canadian National Collection of Insects and Arthropods, Ottawa, Canada.
Photomicrographic images of specimens preserved in transparent amber were prepared using digital cameras attached to stereomicroscopes or to an Infinity K-2 long-distance microscopic lens. Fossils preserved in opaque amber were first detected using propagation phase contrast X-ray synchrotron microradiography, then three-dimensionally imaged using microtomography (PPC-SRµCT), a non-invasive method which allows incomparable possibilities for the visualization of both external and internal structures of amber fossils (Soriano et al. 2010;Perreau and Tafforeau 2011). Imaging was performed on beamline ID 19 of the European Synchrotron Radiation Facility (ESRF) in Grenoble using local tomography protocol (Tafforeau et al. 2006;Lak et al. 2008). The microtomographic scan of specimen IGR.ARC-370.7 was performed using a monochromatic beam at 30 keV with an isotropic voxel size of 5.06 µm and 990 mm of propagation distance. The tomography was obtained using a 180 degree continuous scan with 1500 projections and 0.5s of exposure time. The scan of specimen IGR.ARC-378.2 was performed at 25 keV with an isotropic voxel size of 1.67 µm, 50 mm of propagation distance, and 0.12s of exposure time. After the scan, data were reconstructed using a filtered back-projection algorithm adapted for local tomography applications (PyHST software, ESRF) and adapted ring artifacts correction protocols. Specimen IGR.ARC-370.7 was segmented in 3D using region growing techniques with VGStudioMax (Volume Graphics, Heidelberg, Germany). All of the synchrotron microtomographic data (original stacks of slices, segmentations, animations, pictures, and 3D-volume models) are available at the paleontological online database of the ESRF (http://paleo.esrf.eu), and 3D models in ABS plastic are deposited with the amber piece in Rennes University and at the ESRF.
French amber. Since the description of G. enigmatica by Perrichot et al. (2004a) based on two males, eight new conspecific specimens have been found, including two females previously unknown, five males, and one specimen of uncertain gender. Three further individuals assignable to Maimetshidae may also belong to this species but are too incompletely preserved for accurate attribution.
Six out of the eight new specimens were found in amber from the same outcrop as the type series, i.e., the Font-de-Benon Quarry near the village of Archingeay, in Charente-Maritime, southwestern France. The amber pieces were collected within the lowermost of two amber-bearing strata, e.g., the level A1sl-A sensu Batten et al. (2010) = A1sl1 sensu Néraudeau et al. (2002). The dating of this level remains problematic, it contains some palynomorphs (dinoflagellate cysts) suggesting a latest Albian age (Dejax and Masure 2005), while recently discovered megaspores are more indicative of the Early Cenomanian (Batten et al. 2010). Two other specimens were collected in a single piece of amber from the same stratigraphic level in the Cadeuil Quarry, about 30 km from Archingeay (see "Arc 1" and "Cdl 1" in Perrichot et al. 2010: figs 1-2).
Similar to the type series, four amber pieces were reworked using a scalpel as a microsaw and the five fossils, separated this way from their syninclusions, were embedded in Canada Balsam between cover slips following the method detailed in Perrichot et al. (2004b). The specimens were assigned collection numbers IGR.ARC-1, IGR.ARC-309.11, IGR.ARC-378.1, IGR.CDL-2.5, and IGR.CDL.2.33. The three other fossils (collection numbers IGR.ARC-370.7, IGR.ARC.378.2, and IGR.ARC-393.4) are preserved in pieces of fully opaque amber and were imaged using PPC-SRµCT as detailed above.
Spanish amber. The material originates from Peñacerrada I, in Moraza, Burgos Province, Basque-Cantabrian Basin, Spain (Peñalver and Delclòs 2010). Each fossil is preserved in a thin polished piece of amber, which has been embedded in a clear, synthetic block of epoxy resin according to the method of Corral et al. (1999) except for MCNA-9373, which is not embedded in epoxy. Specimen MCNA-9928, type specimen for one of the new species described herein, is well-preserved and almost complete. Specimen MCNA-13049, holotype for the second species from Spanish amber, is missing the apical parts of the metasoma, of the right antenna, and most legs. Other specimens are incomplete and fossilized in rather opaque amber, partly covered by small bubbles or foggy material, so that some parts are hidden or poorly visible.
Lebanese amber. The material originates from an outcrop near Maknouniyyeh Village, Caza (Department) of Jezzine, in southern Lebanon, which corresponds to an ancient field that was used for lignite mining during the French governance of Lebanon and World Wars I and II. The amber is found with lignite in grey lenses of clay corresponding to channels intercalated between fluvial sand deposition of Neocomian age. The precise dating of this sandstone remains problematic and could be anywhere between the Hauterivian and Early Aptian ). The amber is dark orange to red, brittle, with a lot of carbonized vegetal inclusions. This may indicate that the resin was produced in response to a forest fire. The specimen considered herein is exquisitely preserved, missing only the apical portions of the mid and hind legs. It was fossilized in a piece of amber together with a beetle, an evaniid wasp, a roach, and a rhagionid fly, but each inclusion was separated from the others and embedded in Canada balsam between glass coverslips. The specimen is provisionally deposited in the Department of Entomology of the MNHN.
Canadian amber. The material was collected from the Taber Coal Zone within the uppermost Foremost Formation, at the Grassy Lake locality in southern Alberta, Canada (McKellar and Wolfe 2010). The specimen was prepared in a similar fashion to the Spanish material described above. The male holotype is nearly complete but is surrounded by a relatively thick layer of dark orange amber with multiple internal fractures; this renders observation difficult. Photographs were taken using glycerin and a cover slip. The type specimen exhibits minor taphonomic distortion, and is missing both metatarsi and much of the forewing apices.
* Unfortunately, the holotype of M. arctica was destroyed. Should new material eventually be discovered a neotype will be necessary in order to stabilize the application of the name for the species, genus, and even family. ** Cretogonalys is the type genus of the family-group name Cretogonalinae Rasnitsyn, 1977 (nomen imperfectum;recte Cretogonalyinae Rasnitsyn, 1977), which, if the genus is definitively placed in Maimetshidae, would make the former family-group name a junior synonym of the latter family.

Comments.
Guyotemaimetsha is most similar to Maimetsha in the absence of cell [2Rs]. It differs in cell [1Rs] being anteriorly petiolate instead of sessile, the hind wing with a free apex of Cu, the absence of a medial line on the vertex, and the presence of tarsal plantulae in females. Indeterminate specimens. IGR.ARC-171 (♂, missing head, anterodorsal part of metasoma, and forelegs); IGR.ARC-191 (♂?, missing part of the head and mostly obscured, preserved in very dark amber); IGR.ARC-275 (♀, missing parts of mesosoma, left legs, and with metasoma mostly obscured by a bacterial film). These specimens agree in most respects with the definition of G. enigmatica but little is preserved and attribution to this species cannot be asserted. All specimens deposited in the amber collection of the Department of Geosciences of the University Rennes I, France.
Diagnosis. As for the genus (see above). Redescription. Male: Integument reddish-brown in color, with dense, minute punctures and fine, decumbent pubescence. Head transverse, with length approximately 0.8x width; ocelli separated from each other by one ocellar diameter; antennae inserted between compound eyes, closer to each other than to compound eye margin or posterior clypeal margin; scape globular in lateral view, laterally compressed in frontal view, with faintly concave apex; pedicel with sides convex; flagellum with dense coat of short, inclined setae, with first article longest, twice length of pedicel; penultimate article as broad as long; apical article with rounded apex; clypeus transverse, about twice as broad as long, with anterior margin rounded and posterior margin straight; mandibles large, with outer margin convex, overlapping apically when closed; right mandible with basal tooth large, second and third teeth equally smaller, apical tooth   largest; left mandible with basal tooth large, median tooth smallest, apical tooth largest. Mesosoma compact, 0.7x as high as long; pronotum in dorsal view reduced to a short neck; mesoscutum broader than long, about 0.4x mesosomal length, abruptely truncate anteriorly to form a flat vertical surface, bordered by a transverse carina at anterolateral corners, with low dorsal convexity; median mesoscutal sulcus crenulate, notauli deeply impressed, slightly diverging anteriorly; mesoscutellum with low dorsal convexity, small triangular axillae separated anteriorly by large foveate groove; propodeum areolate, gradually sloping to pronounced posterior lip; meso-and metapleuron with anterior margin foveolate. Forewing hyaline, with costal cell distinctly enlarged  trapezoidal, narrowed toward apex, with outer surface slightly convex, with short erect setae around apex; cerci small, spatulate, inserted just anterior to parameres.
Female: Very similar to male but with pedicel cylindrical and each leg with a small plantar lobe (or tarsal plantula) on ventral apex of tarsomeres I-IV; ovipositor approximately as long as metasomal length, apex acute. Integument sculpturing and pubescence not visible, altered on specimen IGR.ARC.1 and not reconstructed in microtomographic scan of specimen IGR.ARC-370.7. Diagnosis. Antennae with 16 articles; pedicel straight; notauli parallel; forewing costal cell thinner than pterostigma width; prestigma incrassate, wider than base of R, and about the length of 1Rs (distinctly separated from pterostigma); pterostigma longer than distance from base of Rs to base of 2r-rs; cell [2R 1 ] short, about 2.4x longer than wide; cells [1Rs] and [2Rs] present but with 2rs-m slightly sclerotized; extremely light nebulous 2m-cu (only visible playing with light incidence angle); protibial spur biseriate apically.

Iberomaimetsha
Etymology. The new genus-group name is a combination of Iberia, referring to the Iberian Peninsula, and Maimetsha, type genus of the family. The name is feminine.
Comments. Iberomaimetsha is well distinguished from Maimetsha and Guyotemaimetsha in the simultaneous presence of cells [1Rs] and [2Rs] (rm cells sensu Rasnitsyn and Brothers 2009); it differs from Afromaimetsha by its parallel notauli (instead of diverging anteriorly); the prestigma is incrassate, clearly wider than basalmost R, not as in Afrapia; the origin of Rs in Iberomaimetsha is well separated from pterostigma, not as close as in Maimetshorapia; the pedicel is straight and not "comma-shaped" as in Ahstemiam (see below); Andyrossia was described from just a forewing but Iberomaimetsha differs clearly in several details, such as the length of cell [2R 1 ] (around 2.4 times longer than wide versus 3.6 in Andyrossia), and the width of cell [C] (narrower than pterostigmal width in Iberomaimetsha versus wider in Andyrossia).  Description. Female (holotype): Body length 2.8 mm. Head rounded in anterior view, length 0.4 mm, width 0.85 mm; compound eyes not especially bulging, oval, large, well separated by 0.43 mm dorsally; basal part of palps not visible but maxillary palps with at least five palpomeres; labial palps with at least three palpomeres; slight, triangular, supra-antennal elevation above torulus, intertorular area flattened; toruli closer to each other than to inner margin of compound eyes; antennae 2.4 mm in length, inserted on frons below midpoint of compound eyes; scape and pedicel short and globular, flagellomeres cylindrical; lengths of antennomeres as follows (all in mm): scape 0.15, pedicel 0.10, flagellomeres 0.22, 0.20, 0.20, 0.20, 0.18, 0.15, 0.14, 0.14, 0.12, 0.12, 0.12, 0.12, 0.12, 0.15; malar space short, 0.15 mm in length. Mesosoma only laterally visible, 1.15 mm in length; pronotum 0.20 mm in length; mesoscutum 0.35 mm in length; mesoscutellum strongly convex, 0.30 mm in length; propodeum slightly rugose, 0.30 mm in length. Only left mid and hind legs are complete, but foreleg can be reconstructed by mixing right and left parts; no visible division of metatrochantellus; tarsi pentamerous, tarsomeres I-IV each with apicoventral plantar lobe (well visible on left metatarsus: Figs 5, 6D); pretarsal claws with small preapical tooth; leg measure-
Male: Very similar to female except in following minor differences: Body length 3.63 mm; tarsi without plantar lobes; metasoma slightly longer than mesosoma.
Etymology. The specific epithet is a patronym honoring Prof. Alexandr P. Rasnitsyn for his numerous important contributions to the study of Hymenoptera and his generous friendship with the authors. Description. Body length (from paratypes, as incomplete metasoma in holotype) around 2.55-2.61 mm. Head rounded in anterior view, length 0.41 mm, width 0.68 mm with a short occipital carina and apparently some polygonal dorsal sculpture; compound eyes not bulging, slightly oval, separated dorsally by 0.39 mm; toruli about at same distance to inner margin of compound eyes and each other; antennae 2.54 mm in length, inserted on frons below midpoint of compound eyes; scape and pedicel short and globular, flagellomeres cylindrical; lengths of antennomeres as follows (all in mm): scape 0.12, pedicel 0.09, flagellomeres 0. 29, 0.28, 0.27, 0.23, 0.20, 0.18, 0.15, 0.14, 0.12, 0.12, 0.11, 0.11, 0.10, 0.12; malar space short, length approximately 0.11 mm. Mesosoma (dorsal view) 0.95 mm in length; pronotum not distinct dorsally; mesoscutal length 0.27 mm, with parallel notauli and longitudinal medial line, all three present as linear series of grooves more than well-delimited lines (Fig. 9); axillae wide and long, well distinct, separating completely mesoscutellum and mesoscutum; mesoscutellum distinctly convex, length 0.22 mm; propodeum 0.29 mm in length, areolate (seen in paratype MCNA 8790). Legs distinctly elongate; division of trochantellus not  orly bent distad 2rs-m. Hind wing difficult to observe, hyaline and densely covered by microtrichia, length approximately 1.22 mm, maximum width approximately 0.41 mm; three strong hamuli present on costal vein in distal half of wing. Metasoma (checked on paratype MCNA 8790) pedunculate, short and slightly flattened, length 0.98 mm, greatest height 0.41 mm; sterna hard, convex; no apparent metasomal armature on sternum II or III.
Etymology. The new genus-group name is a combination of Ahirom, Phoenician king of Byblos (ca. 1000 BC) whose sarcophagus bears the oldest inscription in the Phoenician alphabet, and Maimetsha, type genus of the family. The name is considered to be feminine.
Etymology. The specific epithet is a matronym honoring Dr Najla Zeidane-Gèze, wife of the collector of the holotype. Diagnosis. Total body length near 1.2 mm; compound eyes globular and protuberant; fine occipital carina present; pedicel 'comma-shaped' in lateral view, 0.54x length of scape and inserted deeply into scape's apex; 14 flagellomeres, cylindrical in shape and progressively shortening; maxillary palpus with at least three palpomeres, Figure 12. a Habitus diagram of holotype female of Ahiromaimetsha najlae Perrichot,Azar,Nel,, with inset of B fore tibial spine C ovipositor D forewing and hind wing venation.
ultimate palpomere with three apical stiff setae, penultimate palpomere with one apical and two mid-body stiff setae; labial palpus apparently with three palpomeres, all short and bearing numerous stiff setae; junction between Sc+R and Rs very close to pterostigma, 2Sc+R shorter than Rs; pterostigma elongate, longer than [2R 1 ], with gradual apical taper; r-rs originating within apical one-third of pterostigmal length; 2R present as small stub; [1M] relatively small, apical corner (junction of Rs+M and 1mcu crossvein) positioned posterior to pterostigma; [1Rs] triangular, bounded by very thin M posteriorly, 2Rs and 1rs-m forming anterior and apical margins of cell, both fade to become nebulous throughout most of cell's length; first apparent metasomal segment much shorter than cell [2R 1 ].
Etymology. The new genus-group name is the inverse of the type genus, Maimetsha, and is considered a meaningless euphonious combination of letters. The name is designated to be feminine in gender.
Comments. Ahstemiam is most similar to Maimetshorapia. The new genus differs in the presence of a prestigma (abscissa of R between 1Rs and pterostigma) that is only slightly inflated (as opposed to distinctly incrassate) and faded apically, as well as a first apparent metasomal tergum that is much shorter than cell [ Type material. Holotype CNC-CAS 1038 (♂) (Fig 13). Deposited in Canadian National Collection of Insects and Arthropods, Ottawa, Ontario, Canada.
Diagnosis. As for the genus (see above). Description. Male (holotype): Body color apparently dark brown, with paler brown antennae and femora, and yellow legs distal to femora (Fig. 13). Head slightly distorted in type specimen, appearing broad (transverse) and foreshortened (exsagittal), with length 0.57× width; ventral margin of gena with prominent notches, more so adjacent to mandibles; frons deeply impressed, antennal bases inserted in shallow depression between compound eyes (Fig. 13); vertex with sparse, short, inclined setae; scape taphonomically distorted, in lateral view, elongate and narrow basally with pronounced apical flare, and concave apex (Fig. 14); pedicel with row of midlength stiff setae inclined upon ventral margin; apical flagellar article slightly wider than preceding articles, and tapering to bluntly-rounded apex; flagellum with dense coat of short, curled setae in various orientations. Mesoscutum with low dorsal convexity, appar- pterostigma pale brown, like tubular veins in wing; Sc+R slightly thicker than other veins, narrowing basally but expanding apical to junction with Rs; fusion of Rs and M angled, veins not parallel to each other; 2rs-m apparently nebulous throughout its course, but preserved in only one wing, which appears taphonomically affected in this region; apex of M not preserved in type specimen; 2Cu significantly longer than 1mcu; 3Cu appears relatively short, terminating posterior to 1rs-m; 2A fading to nebulous vein at midlength of cell [2Cu]. Hind wings poorly visible; apparent length near 0.64 mm; only anterior veins partly visible; broad, open costal cell apparent near apex of Sc+R; R appears to curve anteriorly and rapidly fade along anterior margin of wing; 2Rs and putative 1rs-m both fade distally, and are removed from 1R by relatively long 1Rs; faint curved vein within posterior portion of wing base assumed to represent A; marginal setae visible along posterior margin of wing are fine, elongate and relatively sparse, with greater density in apical positions. Legs with pervasive coat of short, stiff setae densely inclined upon most surfaces; pro-and mesocoxae with elongate setae inclined upon ventral surface; profemur with two rows of short, stiff setae suberect upon ventral surface, protibia bearing row of at least three stout spines approximately one-half of calcar's length on posterior surface; calcar gently curved and robust (as wide as probasitarsus), deeply inserted into protibial apex, extending only slightly beyond apex; fine setae inclined upon both sides of calcar, and matching longitudinal comb of erect spicules on basal half of probasitarsus; probasitarsus length slightly less than all subsequent tarsomeres combined, with approximately four irregularly distributed spines upon apical half of plantar surface; protarsomeres III and IV much shorter than others, one-half to two-thirds length of protarsomere V; all tarsi with serrate pretarsal claws and large arolium, with two apical spines on all tarsomeres (potentially absent on protarsomeres, but orientation obscures observation); meso-and metacoxae both approximately 1.5× length of procoxa, with broad bases and apical constriction; mesofemur with two rows of short, stiff setae inclined upon ventral surface; mesotibia with patch of fine, short spines along posterior surface near apex; two mesotibial spurs short and stout, slightly longer than apical width of mesotibia, and bearing minute setae along both margins; metafemur with significant midlength inflation, laterally compressed, with two rows of short, stiff setae suberect along ventral surface; metatibia with moderate apical expansion, bearing two apical spurs slightly longer than metatibial apical width, as well as comb-like row of six spicules each approximately twothirds of spurs' length; metatarsi not preserved. Metasoma with six apparent terga; terga appear to bear frills of elongate setae along posterior and lateral margins, terga more pilose within posterior of metasoma; parameres spatulate, each with four elongate setae erect on apex.
Female: Unknown. Etymology. The specific epithet is the Latin diminutive noun in apposition, cellula (meaning, "small room") and refers to the very small size of cell [1Rs].

Key to genera and species of Maimetshidae
The following key is modified from that of Rasnitsyn and Brothers (2009 Notauli more or less parallel (Fig. 9)

Discussion
The new specimen from Canadian amber extends the temporal range of the family into the Campanian (from the Barremian to the Campanian), as the previous youngest exemplar was Maimetsha, from the Santonian amber of Taimyr (Siberia). Our new record also extends the palaeobiogeographic distribution of the family to encompass North America (from south Gondwana to north Laurentia), suggesting an origin during the Early Mesozoic, perhaps sometime in the mid-Jurassic.
Certainly much remains to be undertaken on Maimetshidae, and research into the family is in its infancy. It will be exciting to develop eventually a broad data set meant to examine the interrelationships among the species (indeed, even addressing maimetshid monophyly!) as well along with their relatives among the Trigonalyidae and Megalyridae (along the lines of the study of Vilhelmsen et al. 2010a), and perhaps also among the Ceraphronoidea s.str. In addition, it is not entirely clear that those specimens known only from wing venation are definitively maimetshids, or alternatively, what other fragmentary taxa previously ascribed to Trigonalyidae or elsewhere might more accurately belong in or near Maimetshidae. Once a thorough cladistic analysis has been undertaken for maimetshids, preferably after a greater wealth of diversity and material is discovered and more species analyzed using modern tools such as synchrotron imaging, then the generic classification of the family should be re-evaluated as it presently appears somewhat finely divided.
For now, what started as a singular species discovered and presciently interpreted by Alex Rasnitsyn 36 years ago (Rasnitsyn 1975), has grown rapidly in diversity within the last six years. We can only hope that this trend will continue in the years to come.