Tanaoknemus Liu and Engel, 2007

LIU, ZHIWEI, ENGEL, MICHAEL S. & GRIMALDI, DAVID A., 2007, Phylogeny and Geological History of the Cynipoid Wasps (Hymenoptera: Cynipoidea), American Museum Novitates 3583, pp. 1-48 : 24-28

Tanaoknemus Liu and Engel , new genus

TYPE SPECIES: Tanaoknemus ecarinatus Liu and Engel , new species.

DIAGNOSIS: Male antenna 14-segmented, with F1 distinctly excavated laterally. Compound eye prominent; gena not expanded behind compound eye; vertex, gena, malar space, and face glabrous; lower face with a simple, more or less complete median carina. Pronotum dorsomedially strongly extended anteriorly; anterior pronotal flange short; lateral pronotal carina present; lateral pronotal surface transversely costate on upper half, and without foveate sculpture. Mesoscutum glabrous; lateral notauli distinct; mesoscutellum posteriorly truncate, without process; mesopleural impression anteriorly present, convergent to a longitudinal impression along ventral margin of lower mesopleuron toward posterior two-thirds and divided into several foveae by vertical carinae; lateroventral carina of mesopectus present and complete; lower mesopleuron ventrally not expanded. Forewing with bulla in Sc+R 1 present; Rs+M issuing from middle of the first free abscissa of M (5 basal vein). Mesocoxa inserted vertically and not obliquely at separate posterior area; metacoxa dorsally distinctly depressed and with a rounded, anterolateral triangular crest; metatibia longer than metafemur by one-third. Petiolar annulus low, postsubpleuron short; petiole slightly longer than wide and longitudinally carinate.

COMMENTS: The presence of a unique mesopleural impression and unusually long tibia separate the genus from all other cynipoids. The lack of the lateral pronotal carina, presence of a bulla in Sc+R 1, and Rs+M issuing from the middle of the first free abscissa of M (i.e., basal vein) suggest affinity with the family Cynipidae . Although the relatively long petiole is a feature often found in Figitidae and is not known in extant Cynipidae , the trait has evolved independently in many Hymenopteran lineages, including several times within Cynipoidea . We therefore interpret its presence in Tanaoknemus as an autapomorphy, and the genus is provisionally placed as a basal clade of Cynipidae .

ETYMOLOGY: The new genus-group name is a combination of the Greek words tanao - (meaning ‘‘long’’ or ‘‘outstretched’’) and knem - (meaning ‘‘the leg between the knee and ankle’’). The name is a reference to the unusually long tibia of the new genus relative to other cynipoids. The name is masculine.

Tanaoknemus ecarinatus Liu and Engel , new species figures 17 , 18

DIAGNOSIS: As for the genus (see above).

DESCRIPTION: Male. Body length 1.20 mm; length of forewing about 1.00 mm (tip of wing not well preserved). Body mostly black; wings hyaline, without any macula or band. Antenna cylindrical, 14-segmented (10-segmented on the other side, but that is apparently an abnormality); F1 laterally excavated; elongate placodeal sensilla present on all flagellomeres. Head compressed longitudinally, attached high to mesosoma; frons, vertex, gena, and malar space glabrous; compound eye prominent, vertically more than twice as high as malar space; gena not expanded behind compound eye. Lateral surface of pronotum transversely weakly costate in upper half; mesoscutum dorsally slightly curved in lateral view, glabrous with sparse pubescence, without transverse costa; median impression and lateral notauli percurrent; mesoscutellum dorsally flat and irregularly sculptured, without posterior processes; mesoscutellar sulcus medially divided into two large foveae by a longitudinal carina; mesopleuron glabrous. Mesocoxa inserted vertically beneath mesopleuron. Propodeum with no processes; nucha short; lateral propodeal carina percurrent and dorsally not curved in lateral view. Wings entirely hyaline and pubescent; wing margins ciliate. Forewing with marginal cell closed, about three times as long as wide; bulla in Sc+R 1 present; 2r-rs oblique, sloping outward posteriorly; areolet large; Rs+M nebulous, arising from the middle of the first free abscissa of M (5 basal vein). First metatarsomere slightly shorter than combined length of second through fifth metatarsomeres; metacoxa dorsally distinctly depressed, anterolaterally with a rounded triangular crest; metatibia dorsolaterally with a distinct longitudinal carina; all pretarsal claws simple, without basal lobe. Petiolar annulus slightly longer than wide and longitudinally carinate, attached low to propodeum; all metasomal terga subequal along middorsal line in lateral view, each with posterior margin oblique and almost straight. Female. Unknown.

HOLOTYPE: Male , CNC CAS-78, Late Cretaceous (Campanian), Medicine Hat, Alberta, Canada; deposited in CNC.

ETYMOLOGY: The specific epithet is derived from Latin and is a combination of e - (meaning ‘‘without’’) and carinatus (meaning ‘‘keeled’’). The name describes the lack of a lateral pronotal carina in the new species.

SUBFAMILY CYNIPINAE LATREILLE TRIBE AYALCINI ASHMEAD

Figures

Fig. 17. Photomicrograph of holotype male of Tanaoknemus ecarinatus Liu and Engel, new genus and species (CAS-78).

Fig. 18. Holotype male of Tanaoknemus ecarinatus Liu and Engel, new genus and species (CAS-78).