We were able to study two additional specimens of this very primitive genus of stratiomyid, both in Canadian amber collected by Ted Pike from Grassy Lake, Alberta (Campanian) (Pike 1995), housed in the RTMP.

RTMP 96.9.1117: Amber is a typical clear, dark yellow with reddish flow lines; it also contains a small spider. The piece is a cylindrical runnel 12 × 4 × 2 mm, with the fly preserved near the middle, which was embedded in epoxy at the AMNH and trimmed to 9 × 13 × 4 mm (including epoxy) for better observation. The fly is laterally very flattened, especially the thorax, and is a male (though details of the genitalia are not observable). Unfortunately, the apex of the mid tibia cannot be observed in detail, so the apparent absence of tibial spurs is uncertain. Wing is slightly distended in length, but otherwise the venation is very similar to Cretaceogaster pygmaeus.

RTMP 96.9.1230: Fly is also preserved in a cylindrical runnel of amber, 7 × 3 (diam.) mm, and embedded in epoxy for careful trimming. The fly is lying at the rounded end of the runnel, with its dorsal surface against the surface of the flow. The thorax is partly decayed and wing venation is obscured. The antenna and mouthparts are visible in ventral view. Specimen is a male, but its genitalic details are also not observable. Mid tibia appears to have a small apical spur, contrary to the original description of the species but in agreement with Woodley (1986: 380).

Antennal flagellum submoniliform, with approximately 7 short flagellomeres tapered in width apicad; articulation between basal 3 flagellomeres faint. Protibia lacking spurs; mesotibia with two short apical spurs (c. 50 µm length). Metatibia probably with one pair of short apical spurs. Vein Rs branches from R₁ in the distal third of vein R. Stem of R₄₊₅ straight, R₄ curved basally, long and subparallel to R₅. Cell d long and narrow, length approximately 3.5x the width; cell m₃ absent.

Lysistrata emerita, sp. n., by present designation.

From the Greek, Λυσιστράτη, meaning “army disbander”, after the comedy by Aristophanes and in reference to the common name for Stratiomyidae, or “soldier flies”. Feminine.

Lysistrata is clearly within the Stratiomyomorpha, and appears closely allied with Stratiomyidae on the basis of the radial branching. The presence of two minute spurs on the mesotibia, and probably a short pair on the metatibia is indicative of either Stratiomyidae or Xylomyidae. A few Recent stratiomyids have a minute apical spur on the mesotibia, whereas xylomyids have either a 0–2–2 or 0–2–1 tibial spur formula. Pantophthalmids have one or two spurs on the mesotibia only, but are distinct from the other two families by the longer branches of R₁ and Rs.

The Recent and primitive genus Parhadrestia James (consisting of two species from Chile) shares some similarities with Lysistrata, both of them possessing a long R₄ vein curved only at the base and with the main branch only slightly divergent from R₅. The genus Montsecia Mostovski, 1999, preserved as a compression in Early Cretaceous (Barremian) limestone of Montsec, Lérida Province, Spain (originally and incorrectly placed in the subfamily Beridinae) also has the fork of R₄+R₅ quite long. This long fork may be a plesiomorphic feature, seen for example in Rhagionidae and Spaniidae.

Lysistrata differs plesiomorphically from Parhadrestia by the following: antenna multiarticulate; wing longer, narrower; R₂₊₃ slightly longer and gradually sloped to C; apex of R₂₊₃ not close to the apex of R₁; R₅ and M₁ slightly divergent instead of parallel; M₁, M₂, and CuA₁ not as divergent (a condition shared with Montsecia); cell d much longer, its length approximately 3× the width (vs. 2× the width in Montsecia and 1.5× the width in Parhadrestia; in most Recent stratiomyids cell d is quite small); CuA₂ more sloped toward CuP (e.g., apex of cell cup acute, instead of truncate [similar to Montsecia], although an acute cell cup is considered apomorphic by Woodley [2001]). In Montsecia the base of M is weak, whereas it is well developed in Lysistrata. Lysistrata has two apomorphic features: small female abdominal segments 6 and 7, which telescope within the proximal ones (in the basal Recent subfamilies Parhadrestiinae, Chiromyzinae and Beridinae segments 6 and 7 are large [Woodley 2001]); also, vein M₃ is lost. Loss of this vein occurs in all Parhadrestiinae and Pachygastrinae, and is frequently absent in Chiromyzinae and Beridinae (Woodley 2001). Absence of M₃ may actually be a ground-plan feature of Stratiomyidae.

The oldest fossil stratiomyiid is Montsecia martinezdelclosi Mostovski (1999), from the same outcrop that yielded several larvae believed to be stratiomyiids (Whalley and Jarzembowski 1985). According to Mostovski (1999), several undescribed stratiomyiids are known from Jurassic and Cretaceous outcrops of Kazakhstan and Russia, although none has as yet been described. Gigantoberis liaoningensis, described as a stratiomyiid by Huang and Lin (2007) from the Early Cretaceous of Lianoning, China, was shown by Zhang (2009) not to belong to this family, which Huang acknowledges (pers. comm. to AA, 2010). The only other Cretaceous stratiomyiids are Cretaceogaster pygmaeus (Teskey 1971; Grimaldi and Cumming 1999; herein vide supra), an incomplete and undescribed species in Turonian-aged amber from New Jersey USA (Grimaldi and Cumming 1999), and the very well-preserved Lysistrata emerita, described below and which is very basal in the family. Diverse stratiomyiids belonging to modern subfamilies and genera, including undescribed species, occur in shales and amber from the Tertiary and were summarized in Evenhuis (1994).

As for the genus.

Body length 5.75 mm. Head length 0.60 mm. Specimen well preserved, but only visible in lateral view. Head slight distorted, with right antenna slightly separated from base. Eyes bare, large, covering most of head; facets not differentiated. Ocellar triangle not visible. Antenna submoniliform, with approximately 7 short flagellomeres tapered in width distad (articulations between 3 basal flagellomeres faint, number of articles difficult to discern); length of antenna approximately equal to length of head; length of flagellum 3× that of scape + pedicel combined. Distal flagellomere distinctly longer and narrower than more basal ones. Palpi reduced, segmentation not discernable; labellum well developed. Thorax: Mesonotum short and compact, finely pilose dorsally, without macrosetae. Scutellum without spines. Surface of notum slightly metallic and foveolate. All legs preserved; protibia lacking spurs; mesotibia with two apical spurs (50 µm long); probably one short apical spur on metatibiae. Length of hind basitarsomere equal to that of tarsomeres 2–5. Wing length 3.05 mm, width 0.75 mm; hyaline, vein Sc straight, length approximately 0.45× wing length, complete. Lengths of costal section of wing between apices of R₂₊₃ and R₁ equal to that between R₁ and Sc. R₂₊₃ arising distant from r-m. R₄₊₅ straight, R₄ curved at base, long and subparallel to R₅. Veins M₁ and M₂ separated at discal cell. Cell m₃ absent, vein M₃ either absent or fused to CuA₁. Abdomen elongate; basal 4 or 5 segments large and wide; apical 5 segments narrow and telescoping. Cercus composed of 2 segments, basal segment longer than apical one.

Holotype, female, MCNA 12698, SPAIN: Alava, Peñacerrada I (Moraza), Escucha Formation, Lower Cretaceous (Albian). Deposited in MCNA. Specimen is well preserved in a clear piece of amber 10 × 7 × 1.5 mm, partially missing the left side of the thorax and the left wing; the amber is embedded in epoxy 15 × 13 × 2 mm. An empidoid fly (Microphorinae) is present as a syninclusion.

From the Latin noun, Emeritus, a name given to retired Roman soldiers, used here in reference to this long-retired (i.e., extinct) species.

Antenna thick, greatest width (in middle) 0.25x total length, with apparently 7 flagellomeres; protibia without apical spur; most distinctive features are in venation, which distinguishes this genus from other Mesozoic xylomyids by: vein M (separating cells br and bm) weak; cell m₃ very small, width and length approximately half that of cell d (these are of equivalent size in other xylomyids, or m₃ is slightly smaller), and, very distinctively, vein R₂₊₃ is uniquely lost.

Cretoxyla azari sp. n., by present designation.

From Cretaceous, and Xylomyiidae.

The closed wing cell m₃ is a feature also seen in some Xylophagidae. Cretoxyla, however, apomorphically has no protibial spur (as in Stratiomyomorpha) and plesiomorphically does not have a reduced alula (a greatly reduced alula occurs in the Xylophagidae). The extent of vein C, particularly whether it extends only to the apex of M₁ or M₂ (Woodley 1986: 1377), unfortunately cannot be checked since the apical quarter of the wing is lost. Vein C is definitely not circumambient. Other features that are important for xylomyid relationships that cannot be observed in the incomplete fossil are the number of palpal segments (1 vs. 2), presence of denticles on the ventral surface of the hind femur (e.g., Solva Walker), and various male and female genitalic structures.

The oldest fossil record of Xylomyiidae is ?Xylomyia [sic] shcherbakovi Mostovski from the Upper Jurassic (Karabastau Formation) of Kazakhastan (Mostovski 1999). Zhang and Zhang (1993) indicated that Mesosolva Hong and Prosolva Hong, also described as xylomyids from the Upper Jurassic of China, belong in another lower brachyceran family. Undescribed Cretaceous xylomyids are from the Upper Cretaceous amber of Siberia (Zherikhin and Sukacheva 1973), and an incomplete specimen of an undescribed species in Spanish amber (vide infra), so Cretoxyla is the oldest Cretaceous xylomyid (Early Cretaceous, Neocomian). Tertiary fossil xylomyids are Solva inornata Melander, 1949 and Xylomya moratula Cockerell, 1914 in late Eocene shale from Florissant, Colorado; and Solva nana Loew, 1850 in mid-Eocene Baltic amber.

As for genus.

Head: Largely preserved, visible in oblique dorsal and ventral views. Head slightly flattened dorsoventrally, wider than deep, but exact proportions unclear since head seems somewhat distorted. Eyes large, bare, facets not differentiated; dorsal margins of eyes widely separated, by distance approximately 3x width of ocellar triangle. Gena/postocciput with fine pilosity; frons bare. Antenna large and thick; length equal to length of head, thickest portion of antenna near middle (width 0.25 × length of antenna). Flagellomeres difficult to discern, apparently 7, all but distal 2 are wider than long; flagellomere “2” [which may be 2 flagellomeres – if sulcus is present it is very obscure] twice the length of other flagellomeres; apical flagellomere small and conical. Mouthparts slightly prognathous, elements separated but difficult to discern; pair of stiff, stylate maxillae apparent, other elements probably include a labrum or hypopharynx, the labium and/or palps (segmentation of possible palps cannot be discerned).

Thorax: Pronotum fairly large, collar-like; mesonotum large, relatively flat; mesonotum, apical 2/3 of mesoscutellum, and anepimeron with homogeneous vestiture of fine, stiff setulae, each setula having a slightly raised, papilla-like base; row of such setulae just above wing base. Only fore leg preserved sufficiently; without spines or spurs even at apex of tibia. Empodium pulvilliform. Halter slender. Wing: Distal quarter lost at surface of amber. Sc complete, meeting C slightly beyond level of crossvein r-m. Vein h in line with short m-cu. Vein R₁ straight. Vein R₂₊₃ lost. Cells br and bm virtually equal in size, bisected by weak vein M. Cell m₃ spindle-shaped, very small, approximately half the length and width of discal cell; vein M₃+CuA₁ incomplete (not reaching wing margin) and long, length only slightly less than length of cell m₃. Cell cup very large, considerably thicker than and extended well beyond apical levels of cells br and bm. Vein A₁ complete, A₂ not apparent; alula present, but not particularly large.

Abdomen: Poorly preserved, genitalia lost.

Holotype, sex unknown, Lebanon (Early Cretaceous, Neocomian): “Hammana/Mdeiru, Aptien inférieur, ” in Azar Collection no. 391, temporarily deposited in Musee National d’histoire Naturelle, Paris. The specimen is partially preserved, missing the right side of the body, most of the legs, and the right wing at the surface of the amber. It is mounted in a shallow glass well in Canada balsam on a glass slide.

Patronym, for Dany Azar, for his extensive contributions to the paleontology of Lebanese amber.

Head: Lost. Thorax: Partially preserved, relatively broad (width of mesonotum equal to length, 1.40 mm), mesoscutellum of moderate size. Notum foveolate and scutellum covered only with numerous fine setulae, no macrosetae. Left wing 3.57 mm long, it and halter entirely preserved; right wing partially preserved. Vein C ends either at apex of R₄ or R₅; Sc long, meets C beyond midpoint of wing length, approximately at same level as crossvein r-m. R₁ parallel and very close to Sc, with slightly sclerotized, pterostigmatic membrane where they diverge slightly at apex. Base of Rs (before fork of R₂₊₃ and R₄₊₅) short, Rs connected to R₁ quite distad, at 0.42 complete length of wing. Veins R₄ and R₅ forked, branches of fork relatively straight (not curved), with R₅ distinctively ending at apex of wing rather than below it. Cell d small, distinctively short (length 2.5x greatest width); closed cells m₃ and cup present, cell m₃ triangular, short branches of M₃+CuA₁ and A₁+CuA₂ present. Alula relatively small. Halter relatively short and stout. LEG: [Presumably] hind leg without macrosetae on it; presence of an empodium difficult to discern, but pulvilli well developed. Abdomen: Relatively broad, ending short of wing apex.

MCNA 8833, Spain: Álava: Peñacerrada I, Escucha Formation, Lower Cretaceous (Albian). Specimen lacks a head, and the thorax and abdomen are only partially preserved.

Because of the incomplete preservation, a precise diagnosis and family placement of the specimen is not possible, so we did not provide a name and formal description. There are genera of lower Brachycera in several families that have a venation similar to this fossil, including the closed cell m₃. A distinctive feature of the fossil is vein R₅ ending at the apex of the wing. This is rarely seen in the lower Brachycera, occuring, for example, in Xylomyiidae and Apsilocephala Kröber, 1914 (Apsilocephalidae). Unlike Apsilocephala, which has the branches of R₄ and R₅ curved, these branches in the fossil are straight. Also, Apsilocephala and most therevids usually have a longer, more slender abdomen (although see Kumaromyia, vide infra), and usually have bristle-like setae on the mesonotum. These features, plus the short branch of Rs and its distal connection to R₁ indicate that the fossil is in the Stratiomyomorpha, not the Asiloidea.

Cratotabanus isdistinguished from modern tabanids by veins M₁, M₂, and M₃ long, with lengths of M₁ approximately the same as that of cell d (vs. 0.5 – 0.7× length of cell d in Recent Tabanidae); R₅ only slightly deviated from the path of vein R₄₊₅ (in most Recent tabanids, excepting Chrysops Meigen 1803, R₅ curved strongly downward). Distinguished from some Cretaceous Tabanidae, as follows: Eotabanoid Mostovski et al. 2003 and Yixian Formation genera with longer R₁ (reaching well past level of apex of cell d); fork of R₄₊₅ in Eotabanoid, Palaepangonius Ren, 1998, and Eopangonius Ren 1998 much longer (about equal in length to vein M₁).

Venation differs from congener by Cratotabanus stenomyomorphus having vein R₄ not strongly upcurved (vs. strongly upcurved) and R₅ slightly downcurved (vs. nearly in line with R₄₊₅).

AMNH NJ-1862 (holotype): Body length 1.0 cm, wing length 8.0 mm. Most of left lateral view and some of dorsal, right lateral, and frontal view of face observable. Specimen apparently female. Head: Eyes bare, large, not dichoptic, no differentiation of facets nor apparent color patterns. Details of frons and face not entirely observable (e.g., presence of frontal callus and subcallus unlikely; development of ocelli not discernable). Antenna with scape and pedicel not observable but apparently short (not projected); flagellomere I apically narrowed to 0.5 × basal width, with 3 faint annuli; remaining 6 flagellomeres stylate, tapered apicad, articles of approximately equal lengths [best seen in frontal view]. Proboscis robust, palps barely discernable (but apparently short, length 0.4 × that of proboscis), labellum well developed; entire proboscis fairly long, length = 0.75 × depth of head. Thorax: Standard proportions for Tabanidae; legs without discernable spurs (although apices of hind tibiae not observable). Metathoracic spiracle also not observable [e.g., presence of postspiracular scale]. Wing: Completely hyaline, no patterning. Base of R_2–5 nearly perpendicular to R₁, not at a sharp, acute angle. Fork of R_4–5 widely divergent and encompassing entire wing tip, base of R₄ perpendicular to R₅, then strongly and concavely curved to meet C; base of R₄ without a small appendix. M₁, M₂, M₃ nearly parallel; M₃ and CuA₁ convergent (not parallel); CuA₁ and A₁ meeting just before wing margin. A₂ extended nearly to wing margin; alula very large. Abdomen: Details (e.g., segmentation of cerci) not observable.

Specimen. AMNH NJ-1081 (paratype): Thorax + abdomen length 8.2 mm, wing length 8.5 mm (from base of basicosta to wing tip). Wing: Basicosta present as a thick, scale-like lobe at base of vein C. C thickened proximally, circumambient. Short crossvein h present, where costal thickening is narrowed. Sc long, 0.6 × length of wing, straight and parallel to vein C. Veins R and base of R₁ also straight, parallel, and close to Sc; apices of Sc and R₁ diverging apically. Dark, heavily sclerotized pterostigma covers and surrounds R₁, vein C, and extends to tip of R₂₊₃. R₂₊₃ straight, turned slightly upward at apex. Stem of R₄ and R₅ straight, base of R₄ nearly perpendicular to this stem, then curved upward and meeting C anterior to tip of wing; R₅ nearly in line with stem of R₄+R₅. Cell d large, length ca. 2.7 × the width; with veins M₁, M₂ and M₃ each deriving directly from apical wall of cell. M veins slightly divergent, long; M₁ slightly longer than cell d, M₃ ca. 0.6 × length of cell d. Crossveins r-m and m-cu in line with each other. Veins CuA₂ and A₁ meet slightly before wing margin, forming long, complete cua cell with very short vein CuA₂+A₁. Vein A₂ well developed, concave to A₁, evanescent apically; anal lobe and anal cell well developed. Alula present but partially obscure. Abdomen: Short, broad, tergites short, typical of tabanids.

Holotype (sex unknown), AMNH NJ-1862, New Jersey (USA): Middlesex Co., Sayreville, White Oaks [Old Crossman’s] pits (Turonian), collected by Stephen Swolensky. Observation of the fly was optimized by embedding the amber in epoxy under vacuum and trimming very close to surfaces of the fly, but the specimen is not well preserved, being occluded with a reddish, crazed layer over most of the body and by similar internal fractures in the piece, as well as by a suspension of fine particles in the amber. Piece is irregular in shape, 10 × 13 mm in largest dimensions. Study of the specimen might benefit from microtomography.

Paratype (sex unknown), AMNH NJ-1081, in Late Cretaceous (Turonian) amber from Crossman’s Pits, Sayreville, New Jersey. Fly is partially preserved: besides the entire right wing and a very small portion of left wing, only the dorsal surfaces of the abdomen and thorax remain; the head and legs are entirely lost. The amber piece is triangular and approximately 19 × 8 × 5 mm, embedded in epoxy but trimmed and polished so as to expose a dorsal view of the fly. The amber itself is light yellow and turbid, with a thick suspension of organic particles that obscures much of the fly. AMNH NJ-1081 differs from NJ-1862 by the following minor venational details: R₁ slightly longer, Rs branches from R₁ at a more acute angle, proximal end of cell d slightly more shallow V-shaped; A₂ slightly shorter. Both specimens are also very similar in body shape and size.

“from New Jersey, ” in reference to provenance.

These are the only tabanids known to be preserved in Cretaceous amber. Other tabanids in amber are from the Miocene of the Dominican Republic and the Eocene Baltic amber (Evenhuis 1994).

Ren (1998) described three genera of putative, compression-fossilized tabanids with long proboscides from the Early Cretaceous Yixian Formation of China. Grimaldi (1999) discussed the characters on which his assignment was made, and concluded that these fossils may not be tabanids. For example, features of Palaepangonius eupterus Ren that are inconsistent with Tabanidae are the short, upturned R₂₊₃, very long veins R₄ and R₅ (half this length and much more divergent in true Tabanidae), and veins A₁ and CuA₂ that do not fuse but meet the wing margin independently (Fig. 4c). These do appear to be tabanomorphs, but may be stem-group taxa to Recent Tabanidae, Athericidae, Pelecorhynchidae, and possibly even Rhagionidae (some fossil rhagionids had long, piercing mouthparts). Another early compression fossil, Baissomyia redita, from the Early Cretaceous Zaza Formation of Russia, was attributed to the Tabanidae essentially on the basis of body shape and styletiform mouthparts (Mostovski et al. 2003), since the antennae and most of the wing (and, thus, most features defining the family) were not preserved. Eotabanoid lordi, from the Early Cretaceous of England, is probably a tabanid, but it too plesiomorphically has long R₄ and R₅ veins, which are nearly symmetrial (in true tabanids R₄ is typically much more curved) (Mostovski et al. 2003) (Fig. 4c). Besides the specimens in New Jersey amber described herein, the only other definitive Tabanidae from the Cretaceous is Cratotabanus stenomyomorphus from the Aptian-aged Crato limestone of Brazil (Martins-Neto and Kucera-Santos 1994). Venation of Cratotabanus stenomyomorphus and Cratotabanus newjerseyensis are extremely similar. Another species of the genus from the Crato Formation is as yet undescribed (Martins-Neto 2003). Diverse Tabanidae occur in Tertiary rocks and amber (summarized by Evenhuis, 1994), but generic assignments of those species described prior to 1950 need to be assessed. Cretaceous fossils assigned to the Tabanidae include the following:

Baissomyia redita Mostovski, Jarzembowski & Coram, 2003: Zaza Formation, Baissa, Transbaikalia, Russia.

Eotabanoid lordi Mostovski, Jarzembowski & Coram, 2003: Durlston Formation (Berriasian), Purbeck Group, Dorset UK.

“Allomyia” [sensu Ren] ruderalis Ren, 1998: Yixian Formation, China.

Eopangonius pletus Ren, 1998: Yixian Formation, China.

Palaepangonius eupterus Ren, 1998: Yixian Formation, China.

Cratotabanus stenomyomorphus Martins-Neto & Santos, 1994: Crato Formation (Aptian), Ceara, Brazil.

“Cratotabanus sp. n.”: Crato Formation (Aptian), Ceara, Brazil (in Martins-Neto 2003: pg. 31, ex: Grimaldi 1990).

Cratotabanus newjerseyensis sp.n.: Raritan Formation amber (Turonian), New Jersey, USA (herein).

A minute, distinctive acrocerid with medial margins of male eyes contiguous above and below antennae, hind and ventral margins of eye strongly emarginate; antennae minute, in middle of head; proboscis vestigial; eyes bare, thorax with very sparse, fine setulae; postpronotal lobes of moderate size, slightly protruding; abdomen devoid of microtrichia and glabrous (possibly reflective). Mediolobus (i.e., “pulvilliform empodium”) and pulvilli pad-like. Venation distinct: All veins sclerotized, none faint; C ends at apex of R₄₊₅; Sc short; R₁ and Rs fork at ca. 0.4× length of wing; cells br and bm continuous, not bissected (vein M extremely faint or lost from this area); two closed radial cells (r₄₊₅ and d), plus cell m₃ present; R₄₊₅ ends near apex of wing, without an apical fork of R₄-R₅ encompassing apex of wing.

Schlingeromyia minuta, sp. n., by present designation.

Patronym in honor of Evert Schlinger, Emeritus Professor of entomology at the University of California, Berkeley, who has devoted his career to the study of Acroceridae and who also has been a very generous patron of systematic entomology. Feminine, following the Greek myia, for fly.

This is a very distinctive, minute acrocerid – in body size quite the opposite of its generic namesake – which is unique for the venation, genitalia, and virtually bare body. Most acrocerids have long, fine pile on the thorax and abdomen, and many have it on the eyes and calypters. Vein Sc is very short in the fossil, and cells br and bm are contiguous. In addition, apparent retention of freely articulated gonostyli in the male genitalia appears to be a significant feature of the genus, since loss of articulated gonostyli through fusion with the gonocoxites is considered an apomorphy of the remainder of the family (Sinclair et al. 1994). The broad, pad-like structure between the pulvilli, called the empodium in homeodactylous flies, is actually a median outgrowth of the pulvilli as based on the detailed but overlooked work of Röder (1986). The true empodium is a bristle-like distal extension of the unguitractor plate. Thus, we are calling the pad-like empodium a mediolobus. Presence of a true (setiform) empodium is considered a synapomorphy of the Heterodactyla (Woodly 1989; Yeates 2002).

Winterton et al. (2007) recently analyzed acrocerid relationships based on sequences, and concluded that the subfamily Acrocerinae is diphyletic, and the subfamilies Panopinae and Philopotinae are monophyletic. Philopotines are particularly distinctive for the hump-backed notum and postpronotal lobes that are so enlarged as to form a collar dorsally over the cervical region. Although the Baltic amber Archaeterphis hennigi superficially resembles Schlingeromyia in small body size and eye shape (Hauser and Winterton 2007), the relatively complete venation of the latter, structure of male genitalia, and pretarsal structure indicate a much more basal position for the Burmese amber species. Relationships of Schlingeromyia to any Recent generic-group or subfamily is obscure and may reflect a stem-group position.

As for the genus.

Body length 3.0 mm, wing length 2.1 mm. Head: Large, spherical. Eyes very large, occupying most of head capsule. Eyes bare, without interfacetal setulae; no dorso-ventral or frontal differentiation of facets. Entire mesal margins of eyes above antennae are contiguous, portion of mesal eye margin below antenna also contiguous. Posterior margin of eye strongly emarginate; ventral margin of eye slightly less so. Antenna minute, length approximately equal to diameter of 2–3 eye facets; consists of small oval pedicel and minute apical style. Mouthparts vestigial. Postocciput with scattered, fine setulae. Thorax: Scutum strongly arched, very large, length of (meso)thorax 1.25 mm (nearly half the body length). Scutellum small. Position of cervical region near ventral surface of thorax. Pair of well-developed postpronotal lobes dorsal to cervical region, posterior surface of lobe slightly concave. Scutum with sparse, short setulae; scutellum with slightly thicker setulae. Legs slender, mesotibia with short pair of apical spurs; apices of tarsomeres with pair of short, thick setae. Length of basitarsomere approximately equal to that of remaining, distal tarsomeres; hind tibia expanded in width apically to approximately twice the proximal width. Pretarsus with claws large; mediolobus and pulvilli large, pad-like. Wing short and slender, length 2.10 mm, greatest width 0.75 mm; membrane with fine, faint pleating/wrinkling over apical and posterior regions, but not in closed cells [best seen in oblique views]. Calypter large, ovoid, greatest diameter 0.58 mm. All veins sclerotized, none faint. C ends at apex of R₄₊₅; Sc short, meets C slightly distal to level of where R₁ and Rs fork. R₁ and Rs fork at ca. 0.4× length of wing; stem of Rs short, approximately 0.2 × total length of Rs. Rs surrounds large r₄₊₅ cell, near middle of which R₂₊₃ branches off to meet C. Vein R₄₊₅ branches off of apex of cell r₄₊₅, apex meets C slightly posterior to wing apex; M₁ also short, branching subapically off of cell r₄₊₅. Tip of wing not encompassed by an apical fork of R₄-R₅. Cell d bounded by M₁ and M₂; slender (ca. 0.3 × thickness of cell r₄₊₅). Cell m₃ slender, trapezoidal, with proximal end slightly opened. Cells br and bm continuous, not bissected (vein M extremely faint or lost from this area). A₁ slender, meeting CuA shortly before wing margin. A₂ not apparent; anal lobe of wing well developed. Calypter large, hemispherical, greatest diameter 0.25 × length of wing. Abdomen: Smaller than thorax, with six tergites visible (tergite I small, tI and tII virtually obscured in dorsal view under postnotum). Tergites entirely bare of microtrichia and setulae; glabrous [probably reflective], with cuticular microsculpture of minute hexagonal cells present. Spiracles not visible near lateral margins of tergites [in pleural membrane?]. Tergites VII-VIII apparently small [not discernable]. Two pairs of male genitalic appendages present: slender dorsal pair (probably gonostyli), thicker ventral pair (gonocoxites), plus terminal, central, membranous appendage, the phallus.

Holotype, Male, AMNH Bu332a, in Burmese amber. Paratype, AMNH Bu332b, in same piece of amber. Both specimens are entirely preserved, though slightly obscured by debris and a few small fractures. The specimens occur in a runnel-shaped piece of dark but transparent amber, 16 × 7 mm, which has been embedded in epoxy. The piece also contains 1 Coleoptera, 1 Hymenoptera (Serpitidae), and 6 other Diptera (Cecidomyiidae, Empidoidea), as well as twisted strands of spider webs. Interestingly, acrocerids are parasitoids of spiders.

Latin, adjective, in reference to the very small size of the species.

A small, primitive acrocerid in Burmese amber easily separated from Schlingeromyia based on the well developed mouthparts; long, fine antennal stylus; dense, fine pilosity on thorax and abdominal tergites; absence of a mediolobus on the pretarsus; absence of tibial spurs; wing apex rounded; and by the venation: Vein C circumambient, cells br and bm completely separated, absence of cells r₄₊₅ and m₃, presence of a very large cell d, vein R₄ present but vestigial (not connected to R₅), veins CuA₁ and CuA₂ each present, vein A₁ vestigial (cell cup not present).

Burmacyrtus rusmithi sp. n., by present designation.

Combination derived from Burma (the pre-junta name for Myanmar) and Cyrtus, nominal genus of Cyrtidae, a formerly used name of Acroceridae.

Derived acrocerid features that Burmacyrtus shares with Schlingeromyia and Recent acrocerids are the following: spherical head with large, holoptic eyes in male; apex of antennal flagellum with simple stylus; presence of a distinct cervical region; wing membrane with fine wrinkling and devoid of microtrichia; and with a large calypter. Apomorphic features in Burmacyrtus that are lacking in Schlingeromyia are fine, dense pilosity; a broadly rounded wing apex; long, fine stylus; and lack (loss) of a mediolobus. The wing shape of Burmacyrtus is similar to that of some Recent acrocerine genera such as Turbopsebius Schlinger, 1972, but the latter genus has cell r₄₊₅ present, veins CuA₁+M₃ fused, and a complete vein A₁, among other features. Like Schlingeromyia, Burmacyrtus is also very basal in the Acroceridae. Some of the derived features in wing venation of the two species in Burmese amber may be due to the very small body size.

As for genus.

Wing length approximately 1.4 mm, body length approximately 2.0 mm. Head: Rounded, spherical. Male eyes bare of setulae, frontally holoptic [dorsum of head not visible], occupying most of head capsule, ventromesal margins of eyes diverging around clypeus; facets in ventral portion of eye not differentiated in size; posteroventral margin of eye with shallow emargination. Basal portion of flagellum small, ovoid; stylus long and very slender, length c. 2 × that of basal portion; apex of stylus with pair of minute setulae. Labellum well developed; palps not evident. Postocciput with dense, fine pilosity. Thorax: Cervical region elongate, but not comprised of elongate postpronotal lobe (which protrudes slightly from anterior surface of scutum); cervical region connected anteroventrally to thorax. Thorax deep. Dorsal surface of mesoscutum and scutellum with dense, fine pilosity. Legs slender, metafemur longest; without spines, bristle, or tibial spurs; tibial and tarsal setulae not in regular rows. Apical portions of tibiae not distinctly broadened. Pretarsal claws large; pulvilli large, mediolobus absent [if setiform empodium present, not visible]. Wing short, with broadly rounded apex and narrow base; surface devoid of microtrichia, with fine wrinkling throughout. Vein C circumambient, though thinner past apex of M₁; small hump in C midway along length of Sc. Sc complete, length ca. 0.4 × that of wing (a thin, faint, incomplete, and apparently spurious vein runs parallel and very close to Sc). Vein R₁ short, length approximately 0.5 × length of stem of R; R₁ and C thickened where they meet. Stem of Rs short, length approximately 0.5 × that of R₁; Rs and where it meets M thickened. R₄-R₅ apparently a vestigial fork (R₄ incomplete, not connected to R₅). Cells r₄₊₅ and m₃ absent; cell d present, large; length of cell d 0.3 × that of wing. Cells br and bm present, separated by well developed basal portion of M. Veins M₁, M₂, M₃ present, originating from apex of cell d. Veins CuA₁ and CuA₂ present, originating from apex of cell bm. Vein A present, but short and vestigial (cell cup absent). Alula and calypter well developed, each with fine wrinkling; calypter approximately 2 × diameter of alula. Halter apparently dark. Abdomen: larger than thorax; sternites well developed, glabrous, without setulae or punctures. Tergites large, with dense, file pilosity; each setula situated in minute puncture. Male genitalia: epandrium well developed, shallow; cerci slender and apically pointed; everted, distal portion of phallus bulbous; subapical portion flanked by pair of flat, setulose lobes. Spiracles not visible.

Holotype, Male, AMNH Bu-RS1, in Burmese amber. The holotype is in excellent condition, though only the ventral and lateral portions are visible (the dorsal surface is obscured by the depth and curvature of the amber). The amber is clear yellow and the fly lies on an internal surface plane that contains bubbles and stellate trichomes. The original piece was drop-shaped, 10 × 16 mm, and contained a small spider, cecidomyiid midge, and berothid lacewing. These inclusions were separated from the fly.

Patronym, for Dr. R.D.A. (Ru) Smith, who generously donated the specimen to the AMNH from his personal collection.

R₁ long, apex reaching to 2/3 length of wing; R₁ branching off of the stem of R quite distad, R₂₊₃ long, branching off of Rs in the distal half of the wing; cells br and bm large, length nearly half that of wing; M₁₊₂ forked; vein A₁ either incomplete or absent. Mesoscutum strongly arched; it and abdominal tergites devoid of bristle-like setae or long pilosity; apical tibial spurs lacking. Body size minute, ca. 1.0 mm in length.

Microburmyia analvena, sp. n. By present designation

Derived from micro- (L.), minute; -burm-, Burma; and –myia (Gr.), fly, in reference to the minute body size and provenance of this brachyceran. Feminine.

The family placement of the two new species in this genus is not entirely certain, particularly since in mythicomyiids vein R₂₊₃ is typically short and its apex fused with R₁. The genus is placed in the Mythicomyiidae since the venation bears a resemblance to the Baltic amber genus Carmenelectra Evenhuis (Evenhuis 2002), though differing from that Baltic amber genus by R₁ branching off of the stem of R quite distad (vs. near the base of the wing), R₂₊₃ branching off of Rs in the distal half of the wing (vs. in the basal half), and by crossveins r-m and cu-m being in line (vs. stepped). Other features of Microburmyia that are consistent with mythicomyiids are the strongly arched scutum, structure of apical antennal articles (with minute stylus in Microburmyia analvena, ovoid first flagellomere in Microburmyia veanalvena), incomplete Sc vein, palpi minute or absent, and the minute body size. Microburmyia is plesiomorphic with respect to all other known mythicomyiids (cf., Evenhuis 2002).

Mythicomyiidae are traditionally (e.g., Hall 1981) and phylogenetically (e.g., Yeates 1994; Woodley 1989; Woodley et al. 2009) placed as the sister group to the Bombyliidae s.s, often classified as a subfamily, but also as a separate family (e.g., Evenhuis 2002). There is strong morphological and molecular support for Bombyliidae + Mythicomyiidae being the sister group to the rest of Asiloidea (Woodley 1989; Yeates 2002; Wiegmann et al. 2011) or the sister group to the rest of Asiloidea and Eremoneura (Sinclair et al. 1994; Trautwein et al. 2010). With the exception of an unforked R₄₊₅ and short or vestigial anal vein in Microburmyia, it is very interesting that its venation is intermediate between that of the Hilarimorphidae and the more specialized venation of mythicomyiines. This would lend support to the hypothesis that Hilarimorphidae is the sister group to the Bombyliidae (Woodley 1989; Yeates 1994; Woodley et al. 2009). Another hypothesis places the Hilarimorphidae (sometimes including the enigmatic and monotypic genus Apystomyia Melander 1950) as the sister group to the Eremoneura (Yeates, 2002) (see also discussion under Apystomyidae, vide infra). Oddly, the recent total-evidence phylogeny of flies placed the Hilarimorphidae (excluding Apystomyia) as sister group to the Acroceridae (Wiegmann et al. 2011), for which there is very limited molecular and no morphological support, although this result does suggest a position of Hilarimorphidae distant from Eremoneura.

Lastly, it is interesting to note that the fossil record of Bombyliidae s.s., exclusive of mythicomyiines, is entirely Tertiary. Bombyliidae is a large, cosmopolitan family (ca. 4, 500 species) of flies that are most diverse in xeric ecosystems, where they are important pollinators of herbaceous plants. Their fossil record in sedimentary matrices and in amber (Baltic, Dominican) is quite diverse for North America and Europe (Evenhuis 1994), suggesting that the bombyliids s.s. radiated rapidly in the early Tertiary.

Distinguished from Microburmyia veanalvena sp. n. (below) by longer wing; presence of an anal vein; fringe of fine (vs. thick) setae on posterior wing margin; antennal style very fine, with very small article between it and basal flagellomere.

A minute fly, body length c. 1.1 mm, thorax length 0.5 mm, wing length 1.15 mm. Head: Short, somewhat flattened anteroposteriad. Cervical region long. Eyes bare, large, well separated; no dorsoventral differentiation of facets; with small, shallow emargination on posterior margin. Proboscis short [palps not visible]. Antenna with basal flagellomere drop-shaped, with sparse setulae; apical style 0.6 × length of basal flagellomere, very thin, with two articles. Three ocelli present. Postocciput expansive, concave. Thorax: Mesoscutum dorsally arched, devoid of setae or setulae; thorax deep in lateral view; mesoscutellum triangular in shape (nearly equilateral), posterior end tilted upward. Coxae of moderate size; legs slender; devoid of setae, tibiae without apical spurs. Pretarsus with large pulvilli; empodium probably setiform. Halter with slender stem, large knob. Wing long, length slightly greater than length of body, wing L/W = 2.72. Costa either without spinules or spinules minute; C reaching slightly beyond apex of R₄₊₅. Posterior margin of wing with fringe of short, fine setae, including alula (setae longer in this area). Vein Sc with apex apparently evanescent, not reaching C. R-R₁ nearly straight; R₂₊₃ 2.0 × length of R₁; R₄₊₅ straight, ends at apex of wing; proximal portion of R₄₊₅ joined to r-m to form distal margin of cell br. Cells br and bm large, br is 0.33x length of wing, W/L cell br = 0.3; cell bm narrower and shorter. Base of M straight, with short apical fork. Crossvein bm-cu slightly shorter than r-m, not in line with each other. CuA₁ and CuA₂ short, curved slightly toward each other. Vein A₁ present, incomplete (reaching to 0.6x distance between vein base and wing margin), apex of vein blunt, not evanescent. Anal lobe and alula small. Abdomen: Short, 1.3 × length of mesothorax, apparently devoid of setae and setulae. Tergites I – V with shallow, median keel; epandrium with pair of large ventral lobes.

Holotype, male: Myanmar: Kachin (northern Myanmar), in Burmese amber, KU Bu079 (Univ. Kansas, Division of Entomology, Natural History Museum). The amber piece containing the holotype is a very transparent, deep amber color, 14 × 7 × 5 mm, which also contains 2 scelionid wasps. The minute holotype is at the surface of a fractured corner.

in reference to the presence of an anal vein (i.e., the Latin noun vena), albeit incomplete.

cf. Microburmyia analvena (above), distinguished by the absence of an anal vein; posterior fringe of setae long, thick; basal flagellomere and style setulose, style with one article, oval.

A minute fly, wing length 0.85 mm. Head: Short, somewhat flattened anteroposteriad. Cervical region with connection anteroventrally on thorax; not visible dorsally. Eyes bare, large, well separated; no dorsoventral differentiation of facets [presence of emargination on posterior margin not visible]. Proboscis short [palps not visible]. Antenna with basal flagellomere ovoid, having dense setulae (longer apicad); apical style 0.6 × length of basal flagellomere, thick (nearly 0.5 × thickness of basal flagellomere), one articled, setulose. Three ocelli present. Postocciput expansive, concave. Thorax: Mesoscutum dorsally arched, devoid of setae or setulae; thorax deep in lateral view; mesoscutellum triangular in shape (nearly equilateral). Legs slender; devoid of setae, tibiae without apical spurs. Pretarsus with large pulvilli; empodium probably setiform. Halter with slender stem, large knob. Wing W/L = 0.43. Costa either without spinules or spinules minute; C reaching slightly beyond apex of R₄₊₅. Posterior margin of wing with fringe of long, thick setae (visible only on left wing), but margin of alula bare. Vein Sc extremely faint, evanescent. R-R₁ nearly straight; R₂₊₃ 2.0 × length of R₁; R₄₊₅ straight, ends at apex of wing; proximal portion of R₄₊₅ joined to r-m to form distal margin of cell br. Cells br and bm large, br is 0.42 × length of wing, W/L cell br = 0.27; cell bm slightly narrower and shorter. Base of M straight, with short apical fork. Length crossvein bm-cu approximately equal to that of r-m, in line with each other. CuA₁ and CuA₂ short, straight and diverging. Vein A₁ absent. Anal lobe differentiated, alula small. Abdomen: Very broad anteriorly, devoid of setae and setulae on tergites. Tergites I – V apparently without shallow, median keel [difficult to discern with preservation]; epandrium with 5–6 long, thick setae on posterior surface, length of setae approximately equal to length of epandrium.

Holotype, Male: Myanmar: Kachin (northern Myanmar), latest Albian to earliest Cenomanian. AMNH Bu1552. Specimen is displayed with wings and legs outspread, but body is only moderately well preserved, with some details obscured beneath layer of deep reddishness. Dorsal view is better than ventral view.

ve- (Latin prefix meaning without), anal vein (L., vena), in reference to this venational character.

It could be argued that these two species might warrant separate genera, based on the differences of antennae, wing fringe, epandrial setae, and proportions of the wing. However, other than the presence/absence of the anal vein, the wing venation is very similar between the two species.

Body stout, abdomen short (length about equal to that of thorax); eyes large, bare; antenna with 3 flagellomeres, second article and third (style) minute; palp one-segmented; legs and thorax with bristle-like setae, no pilosity except for postoccipital region; hind coxa with small knob on anterior surface; thickness of metatarsi equal that of metatibial base; wing with C ending between apices of R₅ and M₁, apex of R₅ ending slightly subapically; R₄ and R₅ divergent, not parallel for any part of their lengths, base of R₄ not perpendicular to stem of R₄₊₅ and R₅ .

Patronym in honor of a great colleague and friend to the senior author, Prof. Kumar Krishna. Appropriately, Kumaromyia (as presently known) is preserved in amber from Burma, a place of significance in Kumar’s early years.

Kumaromyia burmitica, sp. n., by present designation.

Psilocephala electrella Cockerell, 1920, is a similar species preserved in Burmese amber, but Kumaromyia burmitica has a smaller body size (wing width 0.75 mm, vs. 1.5 mm in holotype of electrella), and differs venationally, specifically with the apex of R₅ meeting C preapically (vs. slightly postapically in electrella), M₁ and M₂ nearly parallel (distinctly divergent in electrella), and apex of M₃ distinctly curved to meet apex of CuA₁ at the wing margin (vs. straight in electrella). The holotype and unique specimen of electrella (NHML In. 20148) is shown in an excellent photograph in Gaimari and Mostovski (2000: fig. 1), and it was examined by the senior author in 2004. It is very partial, with most of the specimen lost (just portions of the scutum and abdomen, two legs and most of both wings remain), so it is very difficult to determine if the two species may be congeneric.

As for the genus.

Small fly, total body length ca. 2.70 mm, thorax length 1.0 mm, wing length (estimated) 2.50 mm. Head: Large, with large eyes. Eyes bare, hemispherical in lateral view (posterior margin flat), no dorsoventral differentiation of facets; inner margins of eyes parallel, separated by distance approximately equal to width between antennal bases. Frons slightly convex, not protruding anteriad; with numerous fine setulae, without calli. Face (“subcranial cavity”) depressed, dark (sclerotized?), glabrous. Antennal scape and pedicel small, approximately equal in size, devoid of thick setae; basal flagellomere largest antennomere, drop-shaped, with dense setulae (no setae); apical two antennomeres (including apical style) small, fine, with style slightly longer than penultimate antennal article. Maxilla with bases (cardostipites) sclerotized and partially fused, palp1-segmented. Labellum slightly larger than palps. Postgena well developed, with numerous fine setae (pilosity). Thorax: Deep in lateral view, pleura apparently devoid of fine or bristle-like setae; scutum with at least 8 pairs of setae [dorsal view, including scutellum, obscured]. Scutum with 3 pairs of notopleurals and 5 pairs in supra-alar region and some setulae; no cervical/postcervical setae. Legs: With thick, stiff setae, primarily on tibiae; fore tibia slender, hind tibia thickest. Fore leg: femur with lateral row of ca. 10 fine setae, tibia with anterior row of 4–5 setae, 4 pre-apical setae. Mid leg: Femur apparently devoid of setae, tibia with 3 evenly-spaced setae on dorsal surface, 2 more ventrad, 4 apically. Hind leg: Coxa with small knob on ventral surface [best seen in left coxa]; femur devoid of setae, tibia with dorsal row of 3–4 setae, lateral row of 3 setae, ventral row of 3–4 setae. Basitarsomere on each leg equal in length to (or slightly longer than) combined length of distal tarsomeres. Each tarsomere with ca. 4 short, stiff setae on rim of distal end. Pretarsus with pair of large pulvilli, empodium setiform. Wing: Large, length nearly equal to that of body. Crossvein h long (space between Sc and C deep); Sc long, length approximately ½ that of wing and slightly shorter than length of R1; apex of Sc apparently incomplete (not meeting C). Apices of Sc and R₁ without pterostigma surrounding apices. Fork of R and Rs deep, proximal to level of vein h. R₂₊₃ straight, without apical curve. Fork of R₄₊₅ not widely divergent; R₅ in line with stem of R₄₊₅, apex of R₅ ending very near apex of wing (not posterior to it); R₄ slightly curved, distinctly shorter than R₅. Cell d slender, greatest width <0.25 × length. Veins M₁ and M₂ slightly divergent, M₂ and M₃ very divergent, all M veins attached to apex of cell d. Apex of M₃ meeting apex of CuA₁ at wing margin. ABDOMEN: Short, only slightly longer than thorax; details (e.g., sternites, genitalia) not observable.

Holotype, female, AMNH Bu131: Myanmar: Kachin State, near Mytikyina (mid-Cretaceous: Late Albian – Cenomanian). Specimen is complete, but the right wing (the only one observable) is folded, and most of the dorsal view is obscured, compromising a complete reconstruction of the venation (fig. 8). The fly is complete, though slightly compressed and with a slight coating of particulate matter over some areas. Its left side is lying on a rough surface of the amber, which obscures that view. The piece also contains some twisted strands of spider webbing.

In reference to the country of origin.

There is little question this fossil belongs to the therevid group, albeit unusually small (within the range in body size of some apsilocephalids and a few genera of Phycinae, such as Efflatouniella Kröber, 1927). Therevid-group features include the antennal structure, bristle-like setae on the scutum and on the legs, the small knob on the hind coxa, as well as the venation. Unlike most Therevidae, Kumaromyia lacks any pruinosity and pilosity (except for the postgena), although Xestomyzinae and Agaphotinae are also robust and have sparse pilosity. Kumaromyia lacks any thick setae that typically encircle the scape and/or pedicel subapically in Therevidae. Also, Kumaromyia has R₄ and R₅ above the wing tip, whereas in Therevidae these are above and below the wing tip, respectively. Unlike Apsilocephalidae, Kumaromyia has a one-segmented palp, vs. two-segmented in Apsilocephalidae, where the basal segment is distinctively thin and long (oddly, palp segmentation and structure was not described for Kaurimyia). The antennal stylus and stout body in Kumaromyia is much more similar to that of Clesthentia, as the stylus in Apsilocephala, Kaurimyia, and even Burmapsilocephala is long and thin. It is quite possible that Kumaromyia is a stem-group taxon for the therevid-family group, not necessarily belonging within Apsilocephalidae or Therevidae.

Fossil Therevidae are scarce, with only five definitive species known, all from the Tertiary. Hauser (2007) and Hauser and Irwin (2005) revised the fossil species:

Ambradolon grimaldii Metz and Irwin 2000: Early Miocene Dominican Republic amber

Arctogephyra agilis (Meunier 1908): mid-Eocene Baltic amber

Dasystethos hoffeinsi Hauser 2007: mid-Eocene Baltic amber

Kroeberiella pinguis (Loew 1850): mid-Eocene Baltic amber

Palaeopherocera scudderi (Cockerell 1909): uppermost Eocene, Florissant, Colorado, USA

Fossil Apsilocephalidae range from the Cretaceous to early Tertiary:

Apsilocephala pusilla (Hennig 1967): mid-Eocene Baltic amber

Apsilocephala vagabunda (Cockerell 1927): uppermost Eocene, Florissant, Colorado, USA

Burmapsilocephala cockerelli Gaimari and Mostovski 2000: mid-Cretaceous Burmese amber

Undescribed sp.: Early Cretaceous amber, Wealden, UK (Chandler 2010: plate 32, fig. 2).

The position of Psilocephala electrella Cockerell 1920 within the therevoid group is uncertain.

Distinguished from the 4 other species in the genus (known only in New Jersey amber) by venation: vein C ending just slightly beyond apex of R₄ (not at apex of R₅); Sc long, distally incomplete (more so than in Hilarimorphites superba Grimaldi and Cumming 1999, the only other species with this trait); veins CuA₂ and A₁ not joined before meeting wing margin (anal cell open distally). Distinguished from Apystomimus by the larger (normal-sized) wings, with an open cup (anal) cell. Also, basal flagellomere is more elongate and triangular in Hilarimorphites burmanica, and the antennal stylus longer than in the other species of Hilarimorphites.

Based on a virtually complete, well-preserved female. Body length (excluding antennae) 1.40 mm; thorax length 0.50 mm; wing length 0.95 mm. Head: Antenna with first flagellomere an elongate triangle in lateral view; apical antennal article(s) form a thin style, with possibly a minute apical article. Eyes large, glabrous. Frons with sparse, scattered setae. Proboscis with broad, flat labellum (palps not visible). Thorax: Notum dome-shaped, with sparse, fine, stiff setae; scutellum with 2 pairs of erect setae. Legs very slender, of moderate length, without distinctive spines or tibial spurs. Wing: typical of Hilarimorphites, except as given in diagnosis above [also, anal lobe may be less developed than in other species, but this area slightly folded under and obscured]. Halter of moderate length, knob slender. Abdomen: Slender, tergites unmodified, cerci and genitalia not fully visible.

Holotype female, AMNH Bu-098, in amber from Myanmar: Kachin, Tanai Village (on Ledo Rd. ca. 105 km Myitkyna). Amber is a deep, clear yellow, 15 × 10 × 5 mm, and was embedded in epoxy and trimmed to a wedge shape in order to maximize a full lateral view of the fly and its venation. The piece also contains a male chironomid and a thrips (Thysanoptera).

From Burma (Myanmar).

Hilarimorphites was known only from Turonian-aged amber of central New Jersey, USA, and besides the new species in Burmese amber a very similar taxon is also now known from the Upper Jurassic of Kazakhstan. Mostovski (1999) described Apystomimus zaitzevi, preserved as a compression from the Karabastau Formation (Upper Jurassic) of the famous Karatau-Mikhailova Lagerstätte. That well-preserved specimen has a venation indistinguishable from that of Hilarimorphites Grimaldi & Cumming, 1999. Apystomimus differs from that genus by having small, brachypterous wings (ca. 0.5× length of the body) and very long cerci (nearly 0.5x length of wing; Hilarimorphites has very small cerci typical of lower Brachycera). Since these are autapomorphic features of Apystomimus, it could be appropriate to synonymize one of the genera (although Apystomimus is more aptly named, Hilarimorphites has date precedence by two months). Hilarimorphites was originally placed in the Hilarimorphidae, and Mostovski placed Apystomimus in Asilomorpha family-incertae sedis (but near the extant genus Apystomyia). Recent Hilarimorpha lack the discal cell, they have the cup cell closed, and lack a well-developed anal lobe while retaining a vestige of the anal vein, so the venation of the fossils is far more easily derived from Apystomyia. Thus, we agree that Hilarimorphites and Apystomima should both be classified in Apystomyiidae. The wing of Hilarimorphites differs from that of Apystomyia by the following: slightly shorter R₁ and R₂₊₃ veins; fork of R₄+R₅ less divergent, the branches slightly longer; cells br and bm significantly larger; cell cup significantly larger, with veins CuA₂ and CuP meeting just before or at the wing margin, or not all (vs. CuA₂+CuP with a long stem in Apystomyia); anal lobe of wing not protruding; and cell d much shorter, its length ca. 3× the width in Hilarimorphites (vs. 5 × the width in Apystomyia).

Hilarimorphites burmanica is intermediate in age between the previously known fossils, and greatly extends the geographic range. An extinct clade or grade of Apystomyiidae occurred minimally throughout Laurasia from the Upper Jurassic to the Upper Cretaceous, which is an age that is consistent with its hypothesized sister-group relationship near Eremoneura (Grimaldi and Cumming, 1999; Grimaldi and Engel, 2005; Wiegmann et al., 2011). Oddly, there are no other fossils as yet known of the family, not even from prolific and diverse Tertiary deposits like Baltic amber.

(emended). Distinguished from Tethepomima by the following: Most or all of antennal flagellum lost; mesonotum bare, devoid of setae or setulae; apical tibial spurs absent; costal vein incomplete, not reaching to apex of Rs; costal spinules and fringe of fine setae on posterior margin of wing lost; alula and anal lobe lost; veins R₂₊₃ and R₄₊₅ lost (Rs simple, unbranched), crossvein r-m lost.

Tethepomyia thauma Grimaldi and Cumming 1999: 6. By original designation.

Distinguished from the other two species of the genus, which are known only from males (Tethepomyia thauma Grimaldi and Cumming: New Jersey amber; and Tethepomyia buruhandi Grimaldi and Arillo: Spanish amber), by the following: thickened costal and Rs veins, bases of M and Cu complete; dorsoventral differentiation of eye facets (in female, undoubtedly more differentiated in males); U-shaped basal flagellomere large, pedicel small, indistinct. Known only from female.

Body length (tip of basal flagellomere to posterior-most surface of tergite VIII) 2.15 mm. HEAD: Hemispherical in female; eyes very large, covering most of head, only small strip of gena exposed [view of face and frons not visible]. Dorsal eyes facets approximately 0.5× diameter of ventral facet; eye completely bare, no interfacetal setulae. No setae apparent on gena or frons. Ocelli possibly on small tubercles – small, digitate lobes in this area [but details obscure]. Antenna with large, crescent-shaped basal flagellomere; pedicel apparently small [indistinct]. Proboscis and palps not visible [ventral surface of head covered with bubble]. Posterior surface of head evenly and shallowly concave. Cervical region long; head not adpressed to pronotum.

Thorax: Small and short, L = 0.55 mm, with scutum arched, posterior half long and sloped; scutum and scutellum devoid of acrostichals or setae. Scutellum short, length ca. 0.20 × that of scutum; posterior margin flat and slightly concave, not acute. Legs bare, devoid of setae or setulae; with femora slightly swollen in middle. Fore and mid coxae adjacent, hind tibia with coxal-trochanteral articulation facing anteriad (hind legs apparently held forward). Tibiae long and slender (slightly shorter than respective femur). Metatibia slightly bowed, as if to fit tightly against ventral surface of femur. Tarsi short, with basitarsomere only slightly longer than tarsomere 2 [most tarsomeres obscured by layer of air). Halter long; knob large, length of stem approximately 2.2 × greatest diameter of knob; stem without setae. Forewing with reduced venation; veins extremely light (particularly M and Cu); microtrichia of forewing either absent or so microscopic as to not be visible; no costal spinules or fringe of fine setulae on posterior margin of wing. Vein C short, extended to only ca. 0.6 × length of wing, sclerotized, swollen towards apex; apex of R₁ fused with swollen portion of C. Rs thick, width slightly increased apicad; vein incomplete, not reaching wing margin/tip. Vein M faint, complete, tip evanescent and not reaching wing margin. Vein CuA faint, with short fork CuA₁–CuA₂ (length of fork 0.7 × length of stem); branches of fork curved towards anal region. What appears as deep fold (CuP?) parallel and posterior to stem of CuA. Faint, short vein A at base of posterior portion of wing; anal lobe and alula not present.

Abdomen: Tergites and sternites well developed, sclerotized; segments I – VI short (I longest), tergite VII long, sclerotized, length approximately equal to that of tII through tVI, with deeply incised membranous region basally, dorsal and lateral surfaces concave. Sternite VII very large, lobe-like, suspended beneath abdomen; apex pointed, bearing three short, sharp spines. Base of tVII apparently articulating with apex of tVI; tVII+VIII formed into a curved, sclerotized, sharp ovipositor-like structure, with a small, sharp, sclerotized spine at tip. Spine at tip of abdomen/oviscapt (sts IX) apparently interdigitating between three spines of sVII.

Holotype, Female: Myanmar, Kachin State, Early Cenomanian. Specimen is in excellent condition and is in the private collection of James Zigras.

Patronym for James Zigras, for allowing preparation and study of this remarkable specimen.

Tethepomyia zigrasi sp. n. appears to be a sister group to Tethepomyia buruhandi + thauma, from Spanish and New Jersey ambers, respectively. Tethepomyia zigrasi retains the bases of M, Rs, and Cu, which the other two species have lost. It shares with Tethepomyia buruhandi and Tethepomyia thauma many losses: of the antennal stylus, tibial spurs, crossvein r-m, veins R₂₊₃ and R₄₊₅, costal vestiture, fringe of marginal setulae on the wing, as well as the reduction of vein C.

With little question the oviscapt of Tethepomyia zigrasi is a hypodermic-like (“aculeus”) structure, probably used for injecting its eggs into hosts. It was probably a parasitoid. An oviscapt of similar specialization has sporadically evolved in Diptera. It occurs in a few Phoridae (e.g., Apocephalus), all Pipunculidae, and within the Schizophora in some Conopidae (e.g., Stylogaster), most Tephritoidea, all Cryptochaetidae, and probably other families. The trait appears to have evolved most often in parasitoid groups (all those listed above except tephritoids). Most tephritoids inject their eggs into fruits or stems, though a few (like Pyrgotidae) are parasitoids. Fine structure of the injecting oviscapt reveals its convergent development: what is labelled as the “ovipositor” in Pipunculidae (Hardy, 1989: 747) is probably a sclerotized, spine-like derivative of the cercus. In Cryptochaetidae the syringe-like oviscapt is sternite VIII; in Tephritoidea the oviscapt is a telescoping structure composed of segments 7–9. Interestingly, Tethepomyia has a suite of other convergent features similar to those of parasitoid families. Like Pipunculidae, Tethepomyiidae possesse large eyes; like Pipunculidae and Cryptochaetidae the family has large pulvilli; and like Cryptochaetidae the basal flagellomere is enlarged and the arista minute to lost. These are probably functionally correlated features.

Distinctive small flies (body length less than 1.5 mm) with antennal stylus arista-like and terminal, having a single article; face without ptilinal suture; median margins of eyes very close on frons; maxillary palpus two-segmented; mesonotum with dorsocentral and scutellar setae; wing venation highly reduced, with R₂₊₃ and R₄₊₅ each unbranched, M unbranched and evanescent at both ends, Cu simple; female with pair of long, digitate, unsegmented cerci.

From Myanmar, country of origin, and –myia, a common suffix referring to the feminine Greek word for fly.

Myanmyia asteiformia sp. n. By present designation.

This is a perplexing little fly. Chaetotaxy of the thorax, the wing venation, and even body shape are strikingly similar to acalyptrate flies in the Asteiidae. Convergent wing features of the two groups include short R₁ and R₂₊₃ veins; a straight R₄₊₅ that meets the tip of the wing, and even microtrichia that are arranged in rows. However, Myanmyia is not even a cyclorrhaphan, by virtue of the terminal (versus dorsal) arista-like stylus, lack of a ptilinum, and presence of two-segmented (vs. 1-segmented) palpi. With the exception of a few very basal Recent and extinct Platypezidae, almost all other Cyclorrhapha have a dorsal arista. Two-segmented palpi exclude Myanmyia from the Eremoneura (the apparent basal segment of the two segmented palpi seen in some Phoridae is probably a palpifer [Cumming and Wood 2009]). While some empidoids (e.g., Cretaceous Nemedina genus-group species [Grimaldi and Cumming 1999]) have short R veins and faint M and Cu veins, the branching pattern for these flies differs significantly at the base from that of Myanmyia.

As for genus.

Body size small, length 1.35 mm (excluding antennae and cerci), slender. Wing length 1.05 mm. Head: Slightly wider than thorax [possibly preservational, as head is slightly compressed]. Antenna with cup-like pedicel, distal edge rimmed with fine, stiff setae; basal flagellomere drop-shaped, width approximately equal to length; arista-like stylus terminal, setulose, 1-articled (no small basal articles), length approximately 3 × length of basal flagellomere. Eyes large (occupying virtually entire lateral surface of head), bare, with slight dorsoventral differentiation of facets (dorsal facets ca. 2 × diameter of ventral ones); inner margins of eyes (on frons) very close, width of separation equal to ca. 3 facet diameters. Ptilinal suture absent. Maxillary palp 2-segmented, with apical segment clavate and basal segment slender. Labrum long, very slender; hypopharynx (?) stylet-like; labellum small. Gena very shallow or barely developed (not apparent). Postocciput broad, concave. Thorax: Slender, with the following dorsal setae (per side): 1 postpronotal, 4 supra-alar/notopleurals, 3 postsutural dorsocentrals (posterior one largest), 2 pairs scutellars [pleura not visible]. Legs of moderate length, setulose, without distinctive spines/spurs. Pretarsus with claws well developed, but no pulvilli. Wing: Long, slender, W/L = 0.33; membrane microtrichia arranged in oblique rows (between R veins) and longitudinal rows (portions of space between R₄₊₅ and M). Vein C slightly beyond apex of R₄₊₅, no humeral or subcostal breaks; with long, sparse spinules. Sc short, very faint [best seen when tilting specimen]. Base of vein R thick, R₁ short (length 0.3 × length of wing); R₂₊₃ unbranched, meeting C at ⅔ the length of wing. R₄₊₅ straight, extended to tip of wing, unbranched. Vein M simple, unbranched, very lightly sclerotized; both ends evanescent. Sc. Vein A thick, heavily sclerotized strip along alular edge of wing. Anal lobe and alula not developed. Halter: with large, darkened knob, stem approximately same length as knob or slightly longer. Abdomen: Tergites I—VII well developed, with sparse setulae, without macrosetae; sternites II, III, IV large, bare; segment V is tubular; VI, VII ring-like; terminal segment bearing pair of long, finger-like, one-segmented cerci. Presence/absence of abdominal muscle plaques not visible.

Holotype, female, AMNH Bu1616, in amber from northern Myanmar: Kachin State, Tanai Village, 105 km NW Mytikyina. The holotype is the sole inclusion in a clear amber-colored piece 9 × 6 × 2 mm. Ventral surface of the thorax and the abdomen are compressed, and a crack through the thorax obscures some details. The left wing of the unique specimen is well preserved, but venation is optimally observed by tilting and observing the piece at various oblique angles. Right wing is twisted, but in oblique view additional details of venation are visible.

L., for like, and Asteia (type genus of the Asteiidae, a family of Schizophoran flies) and Latin –formia, meaning like, in reference to the similarity of the unrelated two taxa in body shape, size, and wing venation.