taxonID	type	description	language	source
2B8AFB005E5553E7B37A3633A025E34E.taxon	materials_examined	Material examined. Holotype. Female imago in Mid-Cretaceous Burmese amber, SMNS collection, inventory number: BU- 321. Well preserved specimen visible in dorsal / ventral aspect. Body and left forewings preserved except of lost distal part of C and Sc; left forewing twisted, covering dorsal side of abdomen; right forewings twisted, only partly preserved, distal part missing; foretibiae damaged; right antenna, foretarsi, right middle leg and left cercus missing (Figs 7, 8, 10). Left hind wing not visible. For measurements see Table 1.	en	Godunko, Roman J., Martynov, Alexander V., Staniczek, Arnold H. (2021): First fossil record of the mayfly family Vietnamellidae (Insecta, Ephemeroptera) from Burmese Amber confirms its Oriental origin and gives new insights into its evolution. ZooKeys 1036: 99-120, DOI: http://dx.doi.org/10.3897/zookeys.1036.66435, URL: http://dx.doi.org/10.3897/zookeys.1036.66435
2B8AFB005E5553E7B37A3633A025E34E.taxon	diagnosis	Diagnosis. Female imago: body length 7.00 mm; forewings with at least four short marginal intercalaries in MA-MP field basally attached to longitudinal veins, six free marginal intercalaries in RS field; hind wing strongly rounded, small, as long as 0.08 x of forewing length, two cross veins between C-Sc, two cross veins between Sc-RA; RS forked; subgenital plate more than 2.00 x as wide as long, convex and widely rounded apically; subanal plate triangular, elongated, rounded apically without cleft.	en	Godunko, Roman J., Martynov, Alexander V., Staniczek, Arnold H. (2021): First fossil record of the mayfly family Vietnamellidae (Insecta, Ephemeroptera) from Burmese Amber confirms its Oriental origin and gives new insights into its evolution. ZooKeys 1036: 99-120, DOI: http://dx.doi.org/10.3897/zookeys.1036.66435, URL: http://dx.doi.org/10.3897/zookeys.1036.66435
2B8AFB005E5553E7B37A3633A025E34E.taxon	description	Description. General colouration of body relatively pale, light brown to dark brown. Ventral side of body slightly darker than dorsal side. Body covered by blackish maculation (Figs 7 A, B, 10). Head. Clypeus expanded anterolaterally, partly covering anterior part of eyes. Eyes brown, elongated, relatively large, widely separated medially; facets of eyes hexagonal. Distance between eyes 0.73 x of head width. Ocelli well preserved, large, without conspicuous colouration. Facial keel small. Antenna brown, approximately as long as head; segmentation hardly distinguishable, therefore not depicted (see Fig. 7 C-D). Thorax. General colouration brown to dark brown. Lateral aspect of thorax not visible. Prothorax narrow, brown. Mesonotal suture transverse, expressed; medioparapsidal suture poorly visible, straight; lateroparapsidal suture distinctly curved laterally; no preserved natural colouration of pigmented area of mesonotum. Ventral side of mesothorax poorly visible; basisternum relatively short and wide distally, furcasternal protuberances distinctly separated. Metathorax brown to dark brown, blackish maculation dorsally (Fig. 7 E). Wings. Forewings hyaline, translucent, relatively narrow; venation poorly recognizable due to wing deformation, pollution on surface and resin influxes [left wing], and damage of distal part [right wing]; venation well visible from dorsal, and partly from lateral side. Veins light brown to brown; relatively small number of cross veins; no jagged edge along of ventral margin (Fig. 8 C-F). General pattern of forewing venation similar to those of male imago of Burmella paucivenosa sp. nov., except for the following features: six free intercalary veins at least in RS field and CuA-CuP; at least four intercalaries in MA-MP field basally attached to longitudinal veins (Fig. 8 C-F). Hind wings hyaline, translucent, small, as long as 0.08 of forewing length; preserved wing is deformed due to embedding, but most probable was naturally strongly rounded, with shallow costal process; venation brown, significantly simplifies; strong reduction of number of longitudinal and cross veins; no jagged edge along of ventral margin. General structure and pattern of hind wing venation similar to those in male imago of Burmella paucivenosa sp. nov., except for the following features: a few cross veins between C-Sc (2 veins), and Sc-RA (2 veins); fork RS present, iRS short, no cross veins in RS field; costal process not prominent (Fig. 9 A-C). Legs well preserved, except for both forelegs with partly missing tibiae and tarsi; no visible strong spines or setae on margins of leg segments. Preserved part of forelegs darker than middle and hind legs, brown to intensively brown (Fig. 8 A, B). For measurements of leg segments see Table 1. Forelegs partly preserved [due to damage of foretibiae the ratio of femur / tibia is not calculated]. Left middle leg completely preserved: length ratio of femur / tibia / tarsus = 1 / 2.23 / 0.70; length ratio of tarsomeres: 1 / 0.88 / 0.88 / 1.00 / 1.50 (5> 4> 3 = 2 <1). Right hind leg much shorter than left one, probably re-grown after previous injury, therefore with changed proportions of tarsomeres: length ratio of femur / tibia / tarsus = 1 / 0.79 / 0.62; length ratio of tarsomeres: 1 / 0.89 / 0.78 / 0.89 / 1.33 (5> 4> 3 <2 <1). Left hind leg: length ratio of femur / tibia / tarsus = 1 / 1.02 / 0.57; length ratio of tarsomeres: 1 / 1 / 0.91 / 0.91 / 1.27 (5> 4 = 3 <2 = 1) (Figs 8 A, B, 10 A). Other leg characters similar to those in male imago of Burmella paucivenosa sp. nov. Abdominal segments completely preserved, light brown to brown, with blackish maculation on terga and sterna; ventral side of abdomen paler than dorsal side. Vestigial gill sockets, not finger-like, well recognizable on segments II, V, and IV; on other segments gill sockets not distinguishable due to body position in amber. Abdominal segments without large and prominent posterolateral projections; no conspicuous elongation of distal segments compared to proximal ones. Subgenital plate relatively broad, more than 2.00 x as wide as long, convex and widely rounded apically. Subanal plate triangular, elongated, moderately narrow and rounded apically without apical cleft. Right cercus completely preserved, brown, darker proximally, approximately as long as body (Fig. 10 A-D).	en	Godunko, Roman J., Martynov, Alexander V., Staniczek, Arnold H. (2021): First fossil record of the mayfly family Vietnamellidae (Insecta, Ephemeroptera) from Burmese Amber confirms its Oriental origin and gives new insights into its evolution. ZooKeys 1036: 99-120, DOI: http://dx.doi.org/10.3897/zookeys.1036.66435, URL: http://dx.doi.org/10.3897/zookeys.1036.66435
3526B888D3275CC2B5D1DB7E34C24AB3.taxon	diagnosis	Diagnosis. Adults of Burmella gen. nov. differ from other mayfly genera by the following combination of features: forewings (a) with small number of cross veins; (b) pterostigma with simple veins, not anastomosed; (c) CuP smoothly curved towards wing base; (d) two secondary bifurcate veins in cubital field; (e) at least several free marginal intercalaries along ventral margin; hind wings (f) strongly rounded, small, as long as 0.08 - 0.14 of forewing length; (g) small number of cross veins; (h) triad RS present or absent; no MA and MP triads; (i) no secondary branches of cubital veins; (j) costal process developed, rounded apically, situated centrally; abdomen (k) with vestigial gill sockets recognizable at least on segments II-VI; genitalia (l) with large median projection of styliger plate, widely rounded apically; (m) three distal segments of forceps strongly elongated and slender; segment II longest, 5 x as long as segment III; segments III and IV approximately of equal length; segment IV expanding apically; (n) penis lobes widely separated by V-shaped cleft; (o) no trace of paracercus. Additionally, in female (p) anterior part of eyes covered by anterolaterally expanded clypeal shield. Subimago and larva unknown.	en	Godunko, Roman J., Martynov, Alexander V., Staniczek, Arnold H. (2021): First fossil record of the mayfly family Vietnamellidae (Insecta, Ephemeroptera) from Burmese Amber confirms its Oriental origin and gives new insights into its evolution. ZooKeys 1036: 99-120, DOI: http://dx.doi.org/10.3897/zookeys.1036.66435, URL: http://dx.doi.org/10.3897/zookeys.1036.66435
626451424D0B5BE0B0D947700EEC6F74.taxon	materials_examined	Material examined. Holotype. Male imago in Mid-Cretaceous Burmese amber, SMNS collection, inventory number BU- 179. Well preserved specimen visible in lateral aspect. Due to fragility, the piece of amber is additionally embedded in translucent resin to seal the specimen from oxygen and prevent mechanical damage. Body and both pairs of wings completely preserved (Figs 1, 4 - 5); most part of right and left foretibiae and both foretarsi missing; most part of caudal filaments missing. For measurements see Table 1.	en	Godunko, Roman J., Martynov, Alexander V., Staniczek, Arnold H. (2021): First fossil record of the mayfly family Vietnamellidae (Insecta, Ephemeroptera) from Burmese Amber confirms its Oriental origin and gives new insights into its evolution. ZooKeys 1036: 99-120, DOI: http://dx.doi.org/10.3897/zookeys.1036.66435, URL: http://dx.doi.org/10.3897/zookeys.1036.66435
626451424D0B5BE0B0D947700EEC6F74.taxon	diagnosis	Diagnosis. Male imago: body length 5.75 mm; forewings with 3 - 4 marginal intercalaries connected with longitudinal veins, two free marginal intercalaries, no cross veins in anal field; hind wings strongly rounded, small, as long as 0.14 x of forewing length, three cross veins between C-Sc, three cross veins between Sc-RA, one cross vein between RA-RSa, one cross vein between RA-RSp, RS not forked; penis lobes relatively simple, obliquely truncate apically, nearly tube-like; strong apical tooth on outer margin.	en	Godunko, Roman J., Martynov, Alexander V., Staniczek, Arnold H. (2021): First fossil record of the mayfly family Vietnamellidae (Insecta, Ephemeroptera) from Burmese Amber confirms its Oriental origin and gives new insights into its evolution. ZooKeys 1036: 99-120, DOI: http://dx.doi.org/10.3897/zookeys.1036.66435, URL: http://dx.doi.org/10.3897/zookeys.1036.66435
626451424D0B5BE0B0D947700EEC6F74.taxon	description	Description. Colouration relatively pale, yellowish-brown to dark brown; eyes and mesonotum darkest, dark brown to blackish; abdominal segments partly translucent; traces of dark brown maculation along of lateral margins of terga (Figs 1, 2, 4, 6). Head. Compound eyes well-developed, large, widely rounded, medially contiguous; upper portion of compound eyes translucent and slightly yellowish apically, brownish-black basally; border between dorsal and ventral portions of compound eyes well distinguishable; lower portion of compound eyes brownish-black (Figs 1, 2 A-C). Facets of compound eyes hexagonal. Ocelli poorly preserved, relatively small, without conspicuous colouration. Facial keel relatively small. Antennae slightly longer than head. Thorax. General colouration yellowish-brown to brownish-black. Prothorax narrow, light brown. Mesonotal suture transverse, distinctly expressed; medioparapsidal suture relatively straight; lateroparapsidal suture distinctly curved laterally; scutellum not modified; no preserved natural colouration of pigmented area of mesonotum. Mesosternum with brownish basisternum and slightly paler furcasternum; basisternum elongated; furcasternal protuberances distinctly separated. Lateral sides of mesothorax light brown to brown, with blackish maculation. Metathorax brown to dark brown, blackish maculation dorsally (Fig. 2 C, D). Wings. Forewings hyaline, translucent, relatively narrow; venation well recognizable, light brown to dark brown; veins darker proximally and slightly paler distally; relatively small number of cross veins, especially in medial, cubital, and anal fields; no jagged edge along of ventral margin of forewings. Pterostigma with 3 - 4 simple veins. Vein sections between C and RA slightly frosted-brown distally; veins C and Sc brown to dark brown, visible all over their length; RS forked near base, after 0.14 of its length; iRS well-developed, connected with RSp by 5 cross veins, not approximated to RSa 1; MA fork slightly asymmetrical, forked after 0.60 - 0.62 of its length; MA 1 and MA 2 connected with iMA by 2 - 3 cross veins; MP asymmetrical, forked after 0.25 of its length, MP 1 and MP 2 basally connected by a single cross vein; iMP relatively short, connected with MP 1 and MP 2 by single cross veins from each side; CuP smoothly curved toward wing base, basally connected with CuA by cross vein cua-cup, CuP connected with A 1 by cross vein cup-a 1, cua-cup located distally from cup-a 1; in cubital field two secondary bifurcate veins iCu 1 + 2 and iCu 3 + 4 arising from CuA (i. e. four veins iCu 1 - iCu 4 each reaching basitornal margin of forewing); basal end of CuP closely approximated to CuA base; A 1 closely approximated to A 2; no cross veins in anal field. Several intercalaries (iRSa, iRSa 2, iMA, iMP) connected to longitudinal veins by crossveins; two small, basally free marginal intercalaries in R and MP fields; no free intercalary veins in cubital and anal fields (Figs 1, 4). Hind wings hyaline, translucent, strongly rounded, small, as long as 0.14 of forewing length; venation light brown to brown; venation significantly simplified, with strong reduction of number of longitudinal and cross veins; ventral margin of hind wings without jagged edge. Few cross veins between C-Sc (3 veins), Sc-RA (3 veins), RA-RSa (one vein), and RA-RSp (one vein); no triads of RS, MA and MP; MA connected with R; MP approaching CuA; no secondary branches of cubital veins; no free marginal intercalaries; costal process rounded apically, markedly protruding above anterior wing margin, situated at nearly middle of hind wing length (Fig. 5 A, B). Legs well preserved, except of tarsi missing in both forelegs; margins of preserved leg segments without visible strong spines or setae. For measurements of leg segments see Table 1. Right foreleg: length ratio of femur / tibia = 1 / 2.02; left foreleg: length ratio of femur / tibia = 1 / 1.96. Right middle leg completely preserved: length ratio of femur / tibia / tarsus = 1 / 0.71 / 0.21; length ratio of tarsomeres: 1 / 1.25 / 1.25 / 1.38 / 1.75 (5> 4> 3 = 2> 1). Left middle leg much shorter than right one, probably re-grown after previous injury, therefore with changed proportions of tarsomeres. Right and left hind legs completely preserved; right hind leg: length ratio of femur / tibia / tarsus = 1 / 0.91 / 0.51; length ratio of tarsomeres: 1 / 1.29 / 1.43 / 1.71 / 2.00 (5> 4> 3> 2> 1). Left hind leg: length ratio of femur / tibia / tarsus = 1 / 0.66 / 0.41; length ratio of tarsomeres: 1 / 1.40 / 1.40 / 2.00 / 2.20 (5> 4> 3 = 2> 1). Patellotibial suture present on middle and hind legs, absent on forelegs. First tarsomere of middle and hind legs fused with tibia. Claws ephemeropteroid on preserved middle and hind legs, with outer claw hooked and inner claw blunt (Figs 1 A, B, 3 A-D). Abdominal segments completely preserved, partly translucent, relatively pale, yellow to brown, with intensively brown maculation on terga laterally and sterna posteriorly. Vestigial gill sockets, not finger-like, recognizable on segments II-VI, poorly visible on segment VII due to influx of resin and cracks. Abdominal segments without large and prominent posterolateral projections; abdominal segments VIII-IX not elongated compared to previous segments. Abdominal sterna slightly paler than terga. Cerci brown, partly preserved; no trace of paracercus (Figs 1, 4, 6 A, B). Genitalia well preserved, light brown to brown, darker maculation on forceps. Styliger plate angulate, mediocaudally deeply incised; median projection large, widely rounded apically, markedly protruding above anterior margin of styliger. Basal segment I of forceps short, with rounded inner margin, slightly wider than long; segment II of forceps strongly elongated, slender distal segments III and IV much shorter, approximately of equal length; segment IV expanding apically; length ratio of forceps segments II-IV: 1.00 / 0.20 / 0.18 (Fig. 6 C, D). Penis lobes widely separated by V-shaped cleft, relatively simple, obliquely truncate apically, nearly tube-like; structure of left penis lobe poorly visible; inner side of right penis lobe probably partly damaged or lost (i. e. looks semicircular from ventral side); strong apical tooth on outer margin; titillators not distinguishable (Fig. 6 C, D).	en	Godunko, Roman J., Martynov, Alexander V., Staniczek, Arnold H. (2021): First fossil record of the mayfly family Vietnamellidae (Insecta, Ephemeroptera) from Burmese Amber confirms its Oriental origin and gives new insights into its evolution. ZooKeys 1036: 99-120, DOI: http://dx.doi.org/10.3897/zookeys.1036.66435, URL: http://dx.doi.org/10.3897/zookeys.1036.66435
