†Kelneria setosa Matile, 1979 by original designation.

Relatively small Macrocerinae with head bearing three closely grouped ocelli forming a triangle; antennae medium-sized, in males exceeding the length of the thorax but shorter than the wing; apical flagellomere ending in an apiculus; anepisternum bearing a few anterodorsal setae, rest of thoracic pleura bare; wings relatively short and broad; vein R1 short, not reaching the mid-length of the wing; basal cell small, not exceeding one-fourth of the wing length; radiomedial fusion and stem of the medial fork short; tibial spurs longer than the tibial diameter; pretarsus with well-developed empodium exceeding the claws; pulvilli small; male genitalia with strongly reduced gonostyli, appearing as small lobes at the outer angles of the gonocoxites; epandrium notched, bearing a pair of lateral processes.

†Kelneria abundare (Meunier, 1904); †Kelneria ciliata (Meunier, 1904); †Kelneria filiformis (Meunier, 1904); †Kelneria setosa Matile, 1979; †Kelneria rovnensissp. nov.; †Kelneria errorissp. nov.; †Kelneria szymonisp. nov.; Kelneria oisensis (Hebert, Ngô-Muller & Nel, 2025)

The two fossil genera, Kelneria and Eokelneria, both occurred in the Eocene of Europe and share numerous morphological similarities. The general habitus of Eokelneria closely resembles that of Kelneria. Both taxa are similar in antennae (length and presence of an apiculus on the apical flagellomere), length of tibial spurs (exceeding the width of the apical tip of the tibia), overall wing venation (Fig. 2).

The principal character used by Hebert et al. (2025) to distinguish Eokelneria from Kelneria is the presence of a row of tibial macrochaetae, described as “large setae inserted into very distinct sockets”, without specifying on which pair of legs these macrochaetae are present. However, Matile (1990) noted that in some specimens of Kelneria a row of dorsal setae, distinctly thicker and darker than the surrounding setation, extends over the apical half of the hind tibia. He further suggested that tibial macrochaetae in Macrocerinae may have evolved through a process of gradual straightening and elongation of microchaetae, as observed in some species of Kelneria from Baltic amber. A thicker and more prominent row of setae is also present on the hind tibiae of K. rovnensissp. nov. In our interpretation, enlarged tibial setae and macrochaetae represent different degrees along a continuous spectrum of morphological variation rather than distinct character states. Consequently, we consider the distinction between them to be largely terminological. In our view, the proposed separation of Eokelneria does not reflect clear generic-level morphological differences, but rather differences in the interpretation of tibial chaetotaxy and in the distinction between macrochaetae and microchaetae. The observed variation in tibial setation is therefore considered to fall within the range of intrageneric variation in Kelneria. It should further be noted that E. oisensis, the only known representative of the genus, was described from a single specimen interpreted as a female. The generic diagnosis of Kelneria relies primarily on characters of the male terminalia. The absence of male genital characters supporting generic separation, together with the overall morphological congruence with Kelneria, does not justify the recognition of a separate genus. Consequently, Eokelneria Hebert, Ngô-Muller & Nel, 2025 is here proposed as a new junior synonym (syn. nov.) of Kelneria Matile, 1979.

Holotype: MALE, preserved in an 11 × 10 × 4 mm piece of Rovno amber (SIZK K-32069) housed in the Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, Kyiv, Ukraine (SIZK); (Figs 3A, 3B, 19[IR spectrum]). Syninclusions: SIZK K-32066–K-32068 (Chelonariidae, Formicidae, Nematocera, stellate hairs).

Late Eocene (Priabonian, c. 36–35 Ma), Rovno amber (Volhynian Uplift), Pugach quarry, Klesov, Rovno Oblast, Ukraine.

Antennae approx. 0.8× wing length, with distinctly separated flagellomeres densely covered with relatively long microtrichia; pedicel subequal in length to scape; palpus very large, with apical palpomere distinctly elongated, longer than subsequent one and longer than first flagellomere; Sc ending in C approx. at level of rb cell tip; m–cu joining cubital vein before level of Rs base; R₂₊₃ approx. 0.4 length of R_2+3+4+5 fork stem; epandrium deeply and broadly notched, bearing long, slender, spinulose lateral processes extending slightly beyond apices of gonopods. Female unknown.

Body (Fig. 3A): approx. 2.5 mm long; wing 1.9 mm long; antennae 1.5 mm long. — Head (Fig. 4A): wider than long; eyes large, well separated, occupying most of lateral surface of head capsule; distinct cerebral sclerite present, posteriorly rounded, with dorsal surface bearing dense, thick setae; ocelli present, lateral ocelli situated on dorsal surface of cerebral sclerite rather than at its margin; position of median ocellus obscured by antennae. — Antennae (Figs 3A, 4A): with 2+14 segments; 0.8× wing length in male, scapus annular in shape, approx. as wide as long; pedicel slightly broader but approx. equal in length to scape, globular in shape, about 1.8× wider than first flagellomere; flagellum with 12 distinctly separated segments, covered densely with relatively long microtrichia; first flagellomere approximately 3.2× as long as broad; subsequent flagellomeres progressively decreasing in length, except the terminal one, which is longer than preceding segment, terminating in a thin apiculus. — Mouthparts (Fig. 4A): palpus large, 1+4 segmented; small palpiger visible; all four maxillary palpomeres longer than broad; second and third palpomeres subequal in length; apical palpomere distinctly elongated, 2.6× longer than the preceding one and 1.5× longer than the first flagellomere; labella very large, well developed, approx. as long as the apical palpomere. — Wing (Fig. 4B, C): broad, 2.2× longer than wide, membrane hyaline without microtrichia and any visible markings; C with microtrichia throughout length; microtrichia visible on dorsal surface of radial and medial veins; C terminates at tip of wing, after end of R₄₊₅, on approx. two third of distance between end of R₄₊₅ and M₁; Sc ending in C approx. at the level of tip of rb cell; sc-r present on approx. half of the Rb length; R₁ ending in C approx. half-length of wing, just after level where M₁₊₂ forks, approx. at the level of Cu termination; R₂₊₃ approx. 0.4 the length of R_2+3+4+5 fork stem; frm ending just after level at which A₁ reaches wing margin; a faint trace of Mb is present, dividing the basal cell into two; M₁₊₂ fork stem approx. 4.8× longer than frm, ending just before level of Cu termination; M₁ approx. 3.2× longer than M₁₊₂ fork stem; m₂ cell opening 1.3× wider than opening of cell M₁; M₃₊₄ base weakened; m₃₊₄ cell opening 1.3× wider than opening of m₂ cell; basal part of M₁₊₂ distinct; m–cu distinct, joining cubital vein before level of Rs base; Cu reaching wing margin; A₁ ending on wing margin; A₂ absent. — Thorax (Fig. 4A): higher than long; scutum weakly convex, densely covered with long, thick setae; scutellum with a row of very long trichia along its margin; anepisternum narrowed dorsally, higher than long, with few setae in the dorsoanterior part; katepisternum higher than long, bare; anepimeron reaching the ventral margin of the pleura, bare; laterotergite and mediotergite bare. — Legs (Fig. 5B, C): fore coxa the longest, with long setae covering entire anterior surface; mid coxa with a several setae anteroapically and with at least two setae anteroexternally; hind coxa the shortest, with a several setae posteroexternally; femora densely and irregularly covered with thin setae; tibiae covered with short, thin, irregularly arranged setae on whole surface, additionally on posterior surface of hind tibia visible row of thicker and more robust setae; fore tibiae with a sensory pit and a single spur, more than 1.5× longer than the apical width of the tibia; mid and hind tibiae without sensory pits, bearing two long spurs, subequal in length, (spurs 1.8 and 2.9× longer apical width of tibia, respectively); claws short; empodium big, longer than claws. — Abdomen (Fig. 3A): densely covered with long setae, all eight segments visible; segment I short, segment II the longest, segment III and IV subequal in length; subsequent segments progressively decreasing in length. — Male genitalia (Figs 5A, 5D–G, 6, 7): epandrium deeply and broadly notched, bearing slender, spinulose lateral processes terminating just before apices of gonopods, several apical setae present; gonocoxites short, broad, fused, oriented parallel to each other; gonostyli strongly reduced, appearing as two small lobes at outer angles of gonocoxites; cerci small; not exceeding length of epandrial processes, with visible marginal setation; anal cone prominent; paired lateral parameres present on either side of aedeagus; phallosome broadened; dorsoventrally flattened, strongly sclerotized.

The species epithet rovnensis refers to Rovno region of Ukraine, from which the holotype originates.

The specimen was found in the clear piece of amber with weight 4 g and size 38 × 10 × 25mm; distinction between gonostyli and gonocoxites is unclear; shape of the anal angle of the wing is hypothesized and indicated by a dashed line, as the anal field of the wing of the holotype is folded.

Holotype: MALE, preserved in a 15 × 10 × 3 mm piece of Baltic amber (GZG.BST.03049) housed in the Geowissenschaftliches Zentrum, Universität Göttingen, Göttingen, Germany (GMUG) (Figs 8A, 8B, 19[IR spectrum]).

Antennae approx. 0.7× wing length, with distinctly separated flagellomeres densely covered with very short microtrichia; palpus small, with apical palpomere subequal in length to the preceding one and shorter than first flagellomere; Sc ending in C distinctly before level rb cell tip; m–cu joining cubital after level of Rs base; R₂₊₃ short, approx. 0.2 length of R_2+3+4+5 fork stem; epandrium with deep, triangular notch, bearing large, triangular lateral processes with very short, dense apical setation, terminating approx. at the level of gonopods apices. Female unknown.

Late Eocene (Priabonian, c. 36–35 Ma), Baltic amber (Sambian Peninsula), Kaliningrad Oblast, Russia.

Body (Fig. 8A): approx. 2.2 mm long; wing 1.9 mm long; antennae 1.3 mm long. — Head (Fig. 9A): wider than long; eyes large, well separated, occupying most of the lateral part of head capsule, distinct cerebral sclerite present, rounded posteriorly, projected posteriorly, dorsal surface bearing several setae approximately half the length of the setae on the scutum; three ocelli present, forming triangle, median ocellus not reduced, lateral ocelli situated on the dorsal surface of the cerebral sclerite, not on its margin. — Antennae (Fig. 9A): with 2+14 segments; 0.7× wing length in male, scapus annular in shape, wider than long; pedicel bigger than scape, as long as broad, globular in shape, about 1.7× wider than first flagellomere; flagellum with 12 distinctly separated segments, densely covered with long microtrichia; first flagellomere approximately 2.7× as long as broad; subsequent flagellomeres progressively decreasing in length, except for the terminal one, which is longer than the preceding one, terminating in a small apiculus. — Mouthparts (Fig. 9A): palpi small; three apical palpomeres visible; all longer than broad; apical and subapical palpomeres subequal in length; approx. 0.7× length of first flagellomere. — Wing (Fig. 9B, C): broad, 2.3× longer than wide, membrane hyaline without microtrichia and any visible markings; C with microtrichia throughout length; microtrichia visible on dorsal surface of all veins except transverse ones; C terminates at tip of wing, after end of R₄₊₅, on approx. two third of distance between end of R₄₊₅ and M1; Sc very short, ending in C distinctly before the level of tip of rb cell; R₁ ending in C before half-length of wing, approx. at level of M₁₊₂ fork, just before the level of Cu termination; R₂₊₃ approx. 0.2 the length of R_2+3+4+5 fork stem; frm ending before level at which A₁ reaches wing margin; a faint trace of Mb is present, dividing the basal cell into two; M₁₊₂ fork stem approx. 4.5× longer than frm, ending just before level of Cu termination; M₁ approx. 3.1× longer than M₁₊₂ fork stem; m₂ cell opening 1.3× wider than opening of m₁ cell; M₃₊₄ base weakened and widely interrupted; m₃₊₄ cell opening 0.9× opening of m₂ cell; basal part of M₁₊₂ distinct; m–cu distinct, joining cubital vein after level of Rs base; Cu reaching wing margin; A₁ termination not visible, as wing is folded; A₂ absent. — Thorax (Fig. 9A): higher than long; scutum weakly convex, densely covered with long setae arranged in two dorsocentral and two acrostichal rows; scutellum with a row of very long trichia along its margin; anepisternum narrowed dorsally, higher than long, with at least three setae on the dorsoanterior part; katepisternum higher than long, bare; anepimeron reaching the ventral margin of the pleura, bare; laterotergite and mediotergite bare. — Legs (Figs 8A, 10B–D): fore coxa the longest, sparsely setulose on anterior surface; hind coxa the shortest, with a several setae posteroexternally; femora irregularly covered with thin setae; tibiae covered with short, thin, irregularly arranged setae on whole surface; fore tibiae with a sensory pit and a single spur, 1.6× longer than the apical width of the tibia; mid and hind tibiae without sensory pits, bearing two long spurs, subequal in length, (approx. 2.4× longer apical width of tibia); claws short; empodium big, longer than claws. — Abdomen (Fig. 8A): covered with long, thin setae, all eight segments visible; segment I short, segment II the longest, subsequent segments progressively decreasing in length. — Male genitalia (Figs 10A–D): epandrium with deep, triangular notch; bearing large, triangular lateral processes with very short, dense apical setation, terminating approx. at level of gonopods apices; gonocoxites short, broad, triangular, partially fused, oriented parallel to each other; gonostyli strongly reduced, appearing as two small lobes at outer angles of gonocoxites; cerci not visible; phallosome bilobed, strongly sclerotized.

The species epithet erroris refers to a taxonomic error whereby the holotype of this species was previously included in the type series of K. abundare.

Crossvein sc–r is not illustrated in the wing drawing, as its likely positioned close to the wing base and cannot be discerned in the holotype; shape of the anal angle of the wing and apical tip of vein A₁ is hypothesized and indicated by a dashed line, as anal field of the wing of the holotype is folded; specimen designated herein as the holotype originates from the type series of K. abundare as defined by Meunier (1904); this misinterpretation was subsequently retained in the generic revision by Matile (1979) and is corrected in the present study.

Holotype: MALE, preserved in a 29 × 19 × 5 mm piece of Baltic amber (specimen MP/5375a). Paratype: FEMALE, preserved in the same piece of amber (specimen MP/5375b) deposited in the Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Kraków, Poland (ISEA PAS) (Figs 19A, 19C, 19[IR spectrum]).

Antennae approx. 0.7× wing length in male, 0.5× wing length in male, with distinctly separated flagellomeres densely covered with very short microtrichia; palpus small, with apical palpomere longer than the preceding one and shorter than first flagellomere; Sc ending in C distinctly before level rb cell tip; m–cu joining cubital before level of Rs base; R₂₊₃, approx. 0.4 length of R_2+3+4+5 fork stem; epandrium with deep, triangular notch, bearing long and narrow triangular processes, terminating approx. at the level of gonopods apices.

Late Eocene (Priabonian, c. 36–35 Ma), Baltic amber, exact locality unknown.

Body (Fig. 11A): male approx. 2.6 mm long; wing 2.2 mm long; antennae approx. 1.6 mm long; female approx. 3.3 mm long; wing 2.6 mm long; antennae approx. 1.4 mm long. — Head (Fig. 13A): wider than long; eyes large, well separated, occupying most of lateral part of head capsule; distinct cerebral sclerite present, rounded posteriorly, projected posteriorly, dorsal surface bearing several setae approximately half length of setae on scutum; three ocelli present, closely grouped, forming triangle, median ocellus not reduced. — Antennae (Figs 11A, 13A): robust, with 2+14 segments; 0.7× wing length in male, 0.5× wing length in female; scapus short, annular in shape, wider than long; pedicel bigger than scape, as long as broad, globular in shape, approx. 2.1× wider than first flagellomere; flagellum with 12 distinctly separated segments, covered densely with very short microtrichia; first flagellomere approx. 3.4× long as broad, subsequent flagellomeres progressively decreasing in length, except terminal one, which is longer than subsequent one, ending with small, weakly developed apiculus. — Mouthparts (Fig. 13A): palpi small; two apical palpomeres visible; longer than broad; apical palpomere distinctly longer than subapical one; approx. 0.6× length of first flagellomere. — Wing of male holotype (Fig. 12A, C): broad, 2.1× longer than wide; membrane hyaline without microtrichia and any visible markings; C with microtrichia throughout its length; microtrichia visible on dorsal surface of all veins, except for transverse veins and Rs; C terminates at the tip of the wing, beyond the end of R₄₊₅, at approximately three quarters of the distance between the end of R₄₊₅ and M₁; h close to the wing base; Sc short, ending in C distinctly before the level of the tip of the rᵦ cell; sc–r present, shortly after the level of h; R₁ ending in C shortly before half-length of the wing, distinctly before the level at which R_2+3+4+5 forks, approximately at the level of Cu termination; R_2+3+4+5 forks distal to the level at which M₁₊₂ forks, beyond half the width of the m₃₊₄ cell; R₂₊₃ approximately 0.4× the length of the R_2+3+4+5 fork stem; frm ending slightly distal to the level at which A₁ is expected to reach the wing margin; a faint trace of Mᵦ present, dividing the basal cell into two; M₁₊₂ fork stem approximately 4.4× longer than frm, ending shortly after the level of Cu termination; M₁ approximately 2.9× longer than the M₁₊₂ fork stem; m₂ cell 1.3× wider than m₁ cell; M₃₊₄ base weakened and partially atrophied; m₃₊₄ cell 1.1× wider than m₂ cell; basal part of M₁₊₂ and m–cu distinct; Cu reaching the wing margin; A₁ ending on the wing margin; A₂ absent; anal angle folded, therefore its shape not discernible. — Wing of female paratype (Fig. 12B, D): broad, 2× longer than wide; membrane hyaline, without microtrichia or visible markings; C with microtrichia throughout its length; microtrichia present on the dorsal surface of all veins except the transverse veins and Rs; C terminates at the wing tip, beyond the end of R₄₊₅, at approximately three quarters of the distance between the end of R₄₊₅ and M₁; h close to the wing base; Sc short, ending in C distinctly before the level of the tip of the rᵦ cell; sc–r present, shortly after the level of h; R₁ ending in C at approximately half the wing length, distinctly before the level at which R_2+3+4+5 forks, shortly after the level of Cu termination; R_2+3+4+5 forks distal to the level at which M₁₊₂ forks, at approximately half the width of the m₃₊₄ cell; R₂₊₃ approximately 0.4× the length of the R_2+3+4+5 fork stem; frm ending distal to the level at which A₁ reaches the wing margin; a faint trace of Mᵦ present, dividing the basal cell into two; M₁₊₂ fork stem approximately 3.9× longer than frm, ending at approximately the level of Cu termination; M₁ approximately 2.8× longer than the M₁₊₂ fork stem; m₂ cell 1.3× wider than m₁ cell; base of M₃₊₄ weakened and partially atrophied; m₃₊₄ cell 1.1× wider than m₁ cell; basal part of M₁₊₂ and m–cu distinct; Cu reaching the wing margin; A₁ ending on the wing margin; A₂ absent; anal angle rounded. — Thorax (Fig. 13A): higher than long; scutum weakly convex, covered with dense, long setation arranged in two dorsocentral and two acrostichal rows; scutellum ovoid in lateral view, with a row of very long trichia along its margin; anepisternum triangular in shape, approximately as long as high, bare; katepisternum rectangular, higher than long, bare; anepimeron small, not reaching ventral margin of pleura, bare; laterotergite and mediotergite bare. — Legs (Figs 11A, 13B–D): fore coxa the longest, covered densely with long setae on entire anterior surface; mid coxa with a few setae anteroapically; hind coxa the shortest, with a row of setae anteroexternally; femora irregularly covered with long, thin setae; tibiae covered with long, irregularly arranged setae; fore tibiae with a sensory pit and a single spur, longer than apical width of tibia (approx. 1.1× longer apical width of tibia); mid and hind tibiae without sensory pits, bearing two long spurs, subequal in length (spurs 2.1 and 2.2× longer apical width of tibia, respectively); claws short; empodium large, longer than claws. — Abdomen (Fig. 11A): covered with long, thin setae, all eight segments visible; segment I short, segment II the longest, subsequent segments progressively decreasing in length. — Male genitalia (Fig. 14A–C, E, F, H, I): epandrium deeply notched, bearing long, narrow, triangular processes reaching apical tips of gonocoxopodites; gonocoxites large, triangular, partially fused, positioned parallel to each other; gonostyles very small, reduced to two lobes at external angle of gonocoxites; cerci ending approx. at the level of epandrial processes tips, densely covered with setae; phallosome strongly sclerotized. — Female genitalia (Fig. 14D, G): tergite X well developed; cerci biarticulate, first segment short, second elongate (nearly 3× longer than subsequent one); sternite VIII divided into two.

The species epithet szymoni is derived from the name Szymon and is honoring Szymon Kaczmarek (University of Lodz, Poland), who provided the holotype specimen.

The two specimens are interpreted as conspecific because the position of the male relative to the female strongly suggests that they were caught in resin either while in copula (and subsequently separated by a flow of resin), during the initiation of copulation, or immediately after copulation. Sexual dimorphism is evident in overall body proportions, with the female being larger and more robust, the antennae of the female are markedly shorter (approx. 0.5× wing length), than those of the male (approx. 0.7× wing length), slight differences are also observable in wing venation R1 terminates slightly before the mid-length of the wing in the male (ending approximately at the level of Cu termination), whereas in the female it reaches approximately the mid-length of the wing (ending distinctly distal to the level of Cu termination), as shown in Fig. 12C, D.