Material

Specimens used in our study were obtained from the following collections (including acronyms used in the text):

Properly verifying the monophyly of the Leiinae requires a wide sampling of genera that at any time have been assumed to be connected with the subfamily. Particularly, Tetragoneura and allied genera (as Novakia, Ectrepesthoneura, and Docosia) have been accepted either as leiines, gnoristines or as an independent group. The initial delimitation of an ingroup for the analysis here included 95 species of all 37 “Leiinae s.l.” genera (including Tetragoneura, Ectrepesthoneura, Novakia, and Docosia). Whenever possible, we tried to use the type species of each leiine genus in the analysis. The genera Allactoneura and Sticholeia have often been placed in a subfamily of their own, but their relationship to the leiines (see discussion below) has been stressed by different authors. The fact that the manotines have often been associated with the Allactoneurinae also makes it indispensable that all of its genera should be integrated into the analysis.

Outgroup sampling is a key issue, since there is no consensus in the literature about the position of the Leiinae in the phylogeny of the Mycetophilidae. Our outgroup list includes nine species of five genera of Sciophilinae, six species of six genera of Gnoristinae, two species of two genera of Mycomyiinae, and four species of four genera of Mycetophilinae (two Exechiini and two Mycetophilini). One species of Keroplatidae was used to root the entire tree. The full matrix includes 117 terminal taxa. Complete information of the specimens used in this study is included in the appendix 3. The list of characters is in appendix 1 and the data matrix is in the appendix 2. A complete list of known Mycetophilidae fossils (appendix 4) and their fossil deposits (appendix 5) were used to infer the age of the main nodes of the backbone of the Leiinae phylogeny. Over a hundred additional species of mycetophilids were slide-mounted and studied, although not formally included in the matrix.

Preparation of Specimens, Morphology Documentation, and Abbreviations

When available, both males and females of each species were studied. Most specimens were dissected and mounted on permanent slides. Specimens were cleared with KOH, dehydrated in ethanol, and mounted in Canada balsam (modified from Walker and Crosby, 1988; Huber and Reis, 2011). In some cases, after clearing, the terminalia were studied in temporary slide mounting with glycerine or gelatin with phenol (modified from Zandler, 2003).

The habitus of the specimens and morphological details of the structures were studied using light microscopy and were photographed with a Leica DC500 camera attached to a Leica stereomicroscope model MZ-16 or a compound microscope model Leica DM2500. Photos were stacked with Helicon Focus 6. The morphological structures were drawn using a camera lucida attached to the compound microscope. Images were edited with Adobe Photoshop CC. All terminal taxa had specimens studied except of the fossils species and the genus Paramanota. Data for Paramanota in the matrix were taken from the literature except for the wing, obtained from a photograph kindly made available by Jan Ševčík.

Along the discussion of male terminalia patterns in the Leiinae, we refer to published illustrations for most genera. Some leiine genera do not have any published illustrations of male terminalia. We include here stacking photographs of 27 species of 20 genera in the subfamily. Slide mounts show relatively transparent structures at different focus levels and stacking does not work as with pinned specimens: structures at different levels often blur together. Our photographs provide illustrations of the general pattern of the male terminalia of part of the leiine genera and we refer to illustrations as they appear published on paper. A full study of the details of the male terminalia morphology in each genus or species, however, is beyond the scope of this paper. Abbreviations for male terminalia plates as follows: adlgc, apico-dorsal lobe of gonocoxite; allgc, apico-lateral lobe of gonocoxite; avlgc, apico-ventral lobe of gonocoxite; aed, aedeagus; allgc, apico-lateral lobe of gonocoxite; avlgc, apico-ventral lobe of gonocoxite; cerc, cercus; ej ap, ejaculatory apodeme; epand, epandrium; gonocx, gonocoxite; gonocx apod, gonocoxite apodeme; gonst, gonostylus; gsdl, gonostylus dorsal lobe; gsl, gonostylus main lobe; gsml, gonostylus medial lobe; gsvl, gonostylus ventral lobe; hypd, hypandrium; ldlep, laterodistal lobe of epandrium; pm, paramare; pm apod, parameral apodeme; st9, sternite 9; syngcxm, syngonocoxite medial sclerite; teg, tegmen.

Phylogeny Reconstruction

The character matrix was constructed using WinClada (version 1.89). Characters were treated as unordered; unobserved states and inapplicable data were coded respectively as “?” and “–.” Some characters were coded as absent or present, in some cases causing interdependence. We retain these characters as separate in order to extract pertinent phylogenetic data from the morphological differences we observed (Lee and Bryant, 1999; Strong and Lipscomb, 1999).

The phylogenetic analyses of the matrix were made under Fitch parsimony (1971), implemented using TNT (Tree Analysis Using New Technologies–Willi Hennig Society Edition; Goloboff et al., 2008). Topologies in TNT were obtained using New Search Technology (Goloboff, 1999; Nixon, 1999; Goloboff et al., 2008), recommended for matrices with more than 100 terminals. According to Goloboff (1999) and Nixon (personal commun.), the new technologies should be used together; Drifting and Ratchet are very similar and the best method for complex data sets is Ratchet (Nixon, 1999). The following parameters were used for the analyses: Max. trees 10,000; Random seed 0; Random addition sequences 200, Sectorial search (sect: slack7); Ratchet 200 interactions; Tree fusing 5 cycles.

The rooting procedure followed Nixon and Carpenter (1993) using an unequivocal outgroup, in this case a species of Keroplatidae. Final trees files were obtained using WinClada software, edited in Adobe Illustrator CC. Bremer support (Bremer, 1994) was calculated for the strict consensus tree using TNT to indicate the extra steps required to collapse a branch. Suboptimal trees with 1–20 extra steps with TBR (Tree Bissection Reconnection) were used to calculate Bremer support values.

We used implied weighting schemes to reduce the potential influence of incongruent characters over nested characters (Goloboff, 1993). In other words, properties of the data were used to reduce the chances that random association between incongruent characters outperform nested characters under equal weight. Initial analyses of the data matrix were made in TNT under different k values—between 1 and 10, 15, 20, and 25—as well as an analysis with equal weight to assess its effect on the final topology. A tree was also obtained using the script “setk.run” (available from Salvador Arias, unpublished data, to choose the best k value) with TNT based on our dataset, which resulted in k = 24.22175. The tree used to discuss character evolution was the majority consensus of the equal weight analysis.

Character Sampling and Morphological Terminology

The matrix (appendix 2) has morphological characters of male and female adults. Some of the characters used here were proposed in the phylogenetic analyses of the Mycetophilidae by Søli (1997), Tozoni (1998), Rindal and Søli (2006), Amorim and Rindal (2007), and Borkent and Wheeler (2013). Several characters are proposed here for the first time. The morphological terminology follows Cumming and Wood (2017), while structures particularly of the thorax and male terminalia features follow Søli (1997), Amorim and Rindal (2007), and Matile (1990). We use here the term “spines,” in accordance with Cumming and Wood (2017), for hardly sclerotized bristles. Unnamed clades on the phylogeny are referred to using the group+ artifact (Amorim, 1982), in which, e.g., the group (A + (B + (C + (D +E)))) is shortened to “group-A⁺,” i.e., the clade including A plus its sister group.

Relationships among Subfamilies of Mycetophilidae

In the majority consensus (but not in the strict consensus) tree (fig. 96), the group of sciophiline genera sampled here forms a single clade. A monophyletic sciophiline was obtained by Borkent and Wheeler (2013), but Søli (1997: 49) found that Paratinia Mik and Drepanocercus Vockeroth do not comprise a monophyletic group with the remaining sciophilines. We do not have Paratinia and Drepanocercus in our taxon sampling and, hence, our analysis does not conflict with or confirm Søli's (1997) or Borkent and Wheeler's (2013) conclusions about the monophyly of the Sciophilinae. There is, however, a large core group of sciophiline genera that comprise a well-defined clade, as stated by Søli (1997) and Borkent and Wheeler (2013).

Plesiomorphies have been often used as diagnostic features of some of the mycetophilid subfamilies, resulting in confusion over the position of some genera in the system. Doubts have been repeatedly raised particularly about the monophyly of the Gnoristinae and about its position in the phylogeny of the mycetophilids (e.g., Väisänen, 1986; Søli, 1997; Søli et al., 2000; Rindal and Søli, 2006; Jaschhof and Kallweit, 2009). It should be no surprise, then, that, even with our limited sampling of gnoristines, the genera of the subfamily fit into two separate clades in our tree, one of them closer to the clade (Mycomyinae + Mycetophilinae) than the other. Borkent and Wheeler's (2013) phylogeny of the Sciophilinae is rooted in Mycomya Rondani, so their result cannot be used for the relationships among mycetophilid subfamilies. All trees in Søli's (1997) study also show the gnoristines as paraphyletic. Kaspřák et al. (2019) have the gnoristines as a grade (i.e., a paraphyletic group) within which the mycetophilines are nested.

The position of the Mycomyinae as sister to the Mycetophilinae (fig. 101) was also recovered by Rindal and Søli (2006) based both on morphological and molecular data. In their study, Manota Williston and Tetragoneura behave as rogue taxa, either close to the base of the family or nested within the sciophilines. The possible paraphyly of the Gnoristinae and the monophyly of a clade (Mycomyinae + Mycetophilinae) are beyond the scope of this study, but it is interesting that the results here are consistent with Rindal and Søli's (2006) study based on very different matrices. The monophyly of a clade including Mycomyinae, Mycetophilinae, and a paraphyletic Gnoristinae was also found by Kaspřák et al. (2019) using molecular data, although their tree has the Mycomyinae as sister of the “Gnoristinae” plus Mycetophilinae. In their study, they sampled two species of manotines that compose a grade at the base of the Mycetophilidae phylogeny.

FIGS. 52–63.

Wings of Leiinae species of Leiini s.s. 52. Caledonileia pusilla Matile. 53. Leia ventralis Say, with a teratology, M4 missing. 54. Neoclastobasis kamijoi (Sasakawa). 55. Greenomyia stackelbergi Zaitzev. 56. Leia fascipennis Meigen. 57. Clastobasis alternans (Winnertz). 58. Leia arsona Hutson. 59. Leia winthemi Lehmann. 60. Clastobasis vicina Matile. 61. Leia spinifera Edwards. 62. Clastobasis sp. 63. Leia amapaensis Lane.

Kaspřák et al. (2019) obtained Allactoneura as the sister of Leia Meigen, both comprising together the sister clade of Garretella—these are the only leiines sampled in their study. The position of both manotine species in their tree greatly differs from what was found here with a wider sampling of manotine and nonmanotine leiine genera and of mycetophilids of other subfamilies. Their results also disagree with the phylogeny of the Exechiini (Burdíková et al., 2019) obtained with molecular data, in which, among the outgroups, the sciophilines compose a grade at the base of the mycetophilids, with one species of Manota coming out as sister of a clade including (Rondaniella + Leia) and (Mycomyiinae + Gnoristinae + Mycetophilinae). Finally, the results from Kaspřák et al. (2019) also disagrees from the reconstruction from Ševčík et al. (2013), in which all four manotine genera group in a clade with the remaining sampled leiine genera (1.00 posterior probability). The node with the sciophilines joining gnoristines +mycomyiines in Ševčík et al.'s (2013) paper has low support (0.68 posterior probability). In that study, as was found here, Ectrepesthoneura, Docosia, and Novakia do not group with the leiines, but with the gnoristine and mycomyiines (no mycetophilines were included in their analysis).

The question of the monophyly of the Leiinae and its position in the system is the core of this paper. Edwards (1925) commented on the similarities between Tetragoneura and Ectrepesthoneura, keeping both genera in the Leiinae. This position was later followed by Hackman et al. (1988), Søli (1997), and Kurina (2004). Tuomikoski (1966) mentioned that both these genera should be excluded from the Leiinae, placing them with Synapha Meigen in the Gnoristinae. Väisänen (1986) placed Tetragoneura and Ectrepesthoneura in the Gnoristinae, but retained Docosia within the Leiinae, a position also held by Bechev (2000). Chandler (1994), Chandler and Blasco-Zumeta (2001), Chandler (2004), and Chandler et al. (2006) kept Novakia and Docosia in the Leiinae, while Chandler (2004) and Chandler et al. (2006) have Tetragoneura and Ectrepesthoneura in the Gnoristinae. In Tozoni's (1998) phylogenetic study of the family, Ectrepesthoneura is the sister group of Novakia, inside a clade also including Tetragoneura, Trichoterga Tonnoir and Edwards, Aphrastomyia Coher and Lane, Thoracotropis Freeman, Impleta Plasmann, and Docosia. Jaschhof and Kallweit (2009) also proposed that Tetragoneura and Novakia (with some other genera) would have gnoristine affinities. The sampling of Gnoristinae genera in this study is relatively small (6 of 29 genera) and the question of the monophyly of the Gnoristinae still needs proper scrutiny.

The position of the Tetragoneura group of genera in the phylogeny of the Mycetophilidae is pending, but not the monophyly of this group nor its position outside the Leiinae. There are several apomorphic features—characters 29:1, 35:1, 63:2, 74:1, 87:1, 93:1—supporting the clade (Docosia + (Novakia + (Ectrepesthoneura + Tetragoneura))), with a Bremer support of 2. The position of Novakia nested within the group has a Bremer support of 4 and corroborates many views in the literature about its relationships with other genera—in fact, the wing venation of these genera is considerably similar (figs. 18–21). Moreover, several features support that Ectrepesthoneura and Tetragoneura are sister genera.

Regarding the position of this clade in the evolution of mycetophilids, we could not find definite evidence that (Docosia + (Novakia + (Ectrepesthoneura + Tetragoneura))) would be sister to the core leiines—although this position cannot be entirely excluded. In none of our trees, however, does this clade nest within the Leiinae. Both the majority consensus (fig. 96) and the strict consensus trees (fig. 97) show these four genera composing a clade in a polytomy with the Leiinae and the clade (Gnoristinae + Mycomyinae + Mycetophilidae). Indeed, one of the possible solutions for this trichotomy is with the clade with Tetragoneura as sister of the remaining leiines, but this is not our conclusion with the currently available data.

This position of the Tetragoneura group raises the problem of its status within the Mycetophilidae. Meunier (1900) proposed a taxon of subfamily rank—Tetragoneurinae—that applies to this clade (see Sabrosky, 1999). On the one hand, if Tetragoneura and related genera collectively correspond to a leiine subclade, we would have to follow Vockeroth (1981), who showed that the name Tetragoneurinae has priority over Leiinae—proposed by Edwards (1925). On the other hand, if this small clade is sister to the Leiinae or sister to a larger clade that includes two or more subfamilies, as appears in our results, it can have subfamily status, separate from the remaining mycetophilid subfamilies, which is the position taken here.

In dealing with the Cycloneura group, Jaschhof and Kallweit (2009) advocated that the problem of the Leiinae is broader and that a proper analysis should encompass additional genera. They stated that the two characters described by Edwards (1925) to delimit the leiines—short R₁, usually shorter than the length of r-m and a longitudinal r-m, aligned with the second sector of Rs—were solid enough to delimit the group for the genera known at Edwards's time, but we now know genera that do not properly fit into this definition. However, Sigmoleia Tonnoir and Edwards (fig. 35), in one hand, has R₁ longer than r-m and r-m is not aligned to R₅. On the other hand, an elongate r-m aligned with the second sector of Rs is present in tetragoneurine genera (and in some degree also seen in the Exechiini mycetophilines).

In Jaschhof and Kallweit's (2009) opinion, genera such as Aphrastomyia (fig. 29), Gracilileia Matile (fig. 25), Mohelia Matile (fig. 28), Novakia (fig. 19), and Tetragoneura (fig. 21) should be excluded from the “Leiini.” In most of these genera, Sc generally “ends in R” (not in C)—actually, the tip of Sc beyond sc-r is lost, so Sc continues through sc-r to reach bR. This feature is typically seen in Gnoristinae (although present elsewhere). Our analysis supports their view on Novakia and Tetragoneura.

The position of Allactoneura (fig. 44) and Sticholeia (fig. 43) deeply nested within the Leiinae (together with the Manotinae) should not at all be a surprise. Edwards's (1925) original placement for Allactoneura was actually as a manotine. Shaw and Shaw (1951) understood that Allactoneura shares similarities with Procycloneura Edwards, especially in the thoracic pleura, assuming leiine affinities for the genus. This position was clearly defended later by Tuomikoski (1966), who considered the genus a member of the Leiinae. Zaitzev's (1982a: 912) revision of Allactoneura indicated that the genus is “sufficiently isolated from representatives of the tribe Leiini both by a whole complex of characters of the imago and of the larva,” but concludes that “judging by the figure of the wing venation (Johannsen, 1909) and the structure of the thoracic sclerites (Shaw and Shaw, 1951), the genus Allactoneura is apparently close to the New Zealand genus Cycloneura Marshall.” This shows that Zaitzev (1982a) probably had a slightly more restrictive concept of the Leiinae (possibly with Leia and more close allies), but he understood that Allactoneura belongs to a wider leiine arrangement. Matile (1993) accepted Allactoneura as part of the “Leiini s.l.”

In Søli's (1997: fig. 45) phylogeny of the Mycetophilidae, obtained with majority consensus, Leia and Rondaniella come out together sister to Allactoneura, the clade with these three genera sister to Eumanota Edwards. This leeine clade is sister to the genera of Mycetophilinae. This led Søli (1997) to reject the “Allactoneurini” as proposed by Väisänen (1986). When Søli (1996: 4) described Sticholeia, he specifically assigned the genus to the Leiinae, mentioning that “the combination of strong, recurved bristles behind the eyes and a regular arrangement of the tibial trichia makes Sticholeia key out as Eumanota (subfamily Manotinae) in most available keys.” He also stated that Sticholeia has “a combination of characters found in members of the subfamily Manotinae and in Allactoneura de Meijere, 1907, and some other genera in the tribe Leiini [s.l.].” Søli (1996: 10) added further ahead, “like Allactoneura and Leiella, Sticholeia has a very short stem of the median fork and a costa not produced beyond the tip of R₄₊₅. In Allactoneura and Leiella, the abdomen is densely clothed by scale-like setae, a character not present in other groups of mycetophilids. Available evidence thus suggests that Sticholeia is the sister group of Allactoneura and Leiella Enderlein combined.”

Jaschhof and Kallweit (2009) extensively discussed features shared by Allactoneura and Sticholeia with other leiines (especially Leiella and Procycloneura), and considered Allactoneura “properly placed” within the leiines. Finally, in Ševčík et al.'s (2013) molecular phylogeny of mycetophilids, dealing with a limited taxon sampling, the Manotinae are sister to a clade with species of Leiinae (including only Leia and Clastobasis Skuse) mixed with Allactoneura and Sticholeia—mycomyines and mycetophilines were not part of the analysis.

We consistently found a clade in which Sticholeia is sister to (Allactoneura + (Manotinae)) deeply nested within the Leiinae. A similar conclusion emerges from Hippa et al.'s (2005) study, as considered below. Apparently, the distinctiveness of Manota and Allactoneura is the main reason for these two genera to have been placed in a separate subfamily. The consequence, however, was that, accepting Manotinae and Allactoneurinae as separate subfamilies, plesiomorphies had inevitably to be used as diagnostic features for the Leiinae, corresponding to a paraphyletic leiine.

Manota is at the core of this discussion. The wing venation of the genus is rather highly modified compared to other mycetophilids (fig. 45), while the other three manotine genera—Eumanota, Promanota Tuomikoski, and Paramanota Tuomikoski (respectively figs. 47, 46, and 48)—are much less derived. Edwards (1933) and later Ševčík et al. (2013) clearly stressed that Eumanota forms “a transition between Manotinae and Leiinae” (Ševčík et al., 2013: 4). Hippa et al.'s (2005) analysis established the relationships among the genera of Manotinae. Their sampling of nonleiine genera was intended to root their analysis of the phylogeny of the Manotinae, not to recover the position of the manotines within the mycetophilids. Our analysis recovers exactly the same results for the relationships among the manotine genera obtained by Hippa et al. (2005), but it is conceivable that Promanota could be sister to Manota. In their analysis, Procycloneura is sister to the “Manotinae,” while the other sampled leiine genera fit in two other clades. One of these clades has Ectrepesthoneura, Aphrastomyia, and Mohelia in a clade sister to (Procycloneura + Manotinae). The other clade has Mycetophila as sister to a clade with leiines including Leiella and Rondaniella together sister of (Leia + Greenomyia Brunetti) and (Allactoneura + Sticholeia).

In our results, the clade including allactoneurines and manotines, as mentioned above, is deeply nested within the Leiinae. This appears consistently in trees obtained with all weighting schemes. The lack in the literature of a formal phylogenetic analysis of the Leiinae with wide taxon sampling and a proper selection of outgroups is probably behind the decision of many authors to keep the Allactoneurinae and the Manotinae separate from the Leiinae, despite evidence of the leiine-manotine-allactoneurine connection. We here ranked the clade of allactoneurines and manotines as a tribe within Leiinae.

Matile (1978) referred to groups of genera that could be excluded from the Leiini s.l., mentioning Allactoneura, the Cycloneura group, and the Tetragoneura group. These are indeed some of the groups that appear as major clades in our tree. Matile (1978) recognized different monophyletic groups of genera visualizing “leiines” as a much smaller, core clade—Leia, Clastobasis, Greenomyia, and Neoclastobasis Ostroverchova—separate from the remaining groups.

Monophyly of the Leiinae

The monophyly of a Leiinae clade—including the genera of the allactoneurines and manotines, and excluding genera of tetragoneurines—is undisputed in our analysis. The monophyly of this group is recovered under all weighting schemes (figs. 96–99, 101). A feature traditionally used to define the Leiinae—the displacement of the base of the radial sector (Rs) distally in the wing, shortening R₁ (char. 88:2 or 3)—is present in most but not all genera of Leiinae. The obvious plesiomorphic condition in mycetophilids for this character, consistently seen in all other subfamilies, is a long R₁, more than three times longer than r-m. This condition is present within the Leiinae only in Sigmoleia. This condition in Sigmoleia seems more a result of a secondary reduction in the length of r-m than to the presence of a “long R₁.” States 1, 2, or 3 of character 88 are also present in the genera of Tetragoneurinae. This is probably one of the reasons for these genera to have been seen in part of the literature as leiines—together with r-m aligned to the second sector of Rs. Within the Leiinae, the condition 1 of character 88 is known in Thoracothropis (fig. 24), Megophthalmidia Dziedzicki (fig. 27), Paracycloneura Tonnoir and Edwards (fig. 30), Indoleia Edwards (fig. 31), Rondaniella (fig. 32), Cawthronia Tonnoir and Edwards (fig. 34), Allactoneura (fig. 44), and Caledonileia Matile (fig. 52). This means that the conditions 2 and 3 originated more than once even within the evolution of the Leiinae.

As was discussed above, on one hand, Thoracotropis, Trichoterga, and Paracycloneura behave as rogue genera in our analysis—their present position in the tree is still not fully reliable—and their relatively long R₁ could be truly plesiomorphic. A relatively long R₁ in Megophthalmidia, Indoleia, Rondaniella, Cawthronia, Allactoneura, and Caledonileia, on the other hand, may be either the consequence of a secondary extension of R₁ or a secondary reduction of the length of r-m. These are, as suggested by Jaschhof and Kallweit (2009), cases of secondary changes in the wing venation in the Leiinae.

There are five synapomorphies for the Leiinae in our tree (14:0, 50:2, 55:1, 62:1, and 101:2), two of which are uniquely derived for the subfamily—the ventral region of the mesepimeron ending at level of the mesopleurotrochantin (50:2) and the mesopleurotrochantin visible laterally (55:1) (fig. 102). The mesopleurotrochantin is a feature seen in some nematocerous families, but they are often much smaller than the condition in the Leiinae. A bauplan of the Diptera thorax is presented by Matile (1990: 40, fig. 18) and the Leiinae thorax pattern is in Oliveira and Amorim (2012: 6, fig. 2). The condition of the pleurotrochantin in the leiines is certainly secondary, i.e., apomorphic. It is worth noting that some apomorphic features present in some leiine genera and in other mycetophilids may have brought confusion. This includes, for example, the long bristle at the apical posterior margin of the antenna pedicel (17:1), the katepisternum with a posterior angle that fits into the mesepimeron (62:1), C ending at level of tip of R₅ (82:1), a long r-m (96:2), and an elongated M₁₊₂ (101:2).

Our analysis also shows that most decisions made in the literature concerning generic status given to leiines were well founded. With only two clear exceptions, leiine genera proposed in the literature correspond to clades, not to specialized subclades (that received generic rank) inside other taxa also of generic rank, rendering the latter paraphyletic. There are plenty of examples. Garretella Vockeroth is a Nearctic representative that shows up sister to Paraleia Tonnoir, known from Australia and South America. Mohelia is an Afrotropical genus sister to the Neotropical Aphrastomyia. Waipapamyia Jaschhof and Kallweit, from New Zealand, proposed as a separate genus by Jaschhof and Kallweit (2009), is sister to the set of the remainder genera of the Cycloneura Marshall group from the Australasian and Neotropical regions. Hence, in terms of the monophyly of genera, most leiines are very well delimited and were shown to be monophyletic. The only two problems, discussed in more detail ahead, concern Leia and Clastobasis. Leia, as delimited today, is paraphyletic in relation to Neoclastobasis, Greenomyia, and Clastobasis, while Clastobasis is itself polyphyletic, intertwined among the species of Leia.

Rogue Genera

Larger clades within the Leiinae in our analysis have good support, and their position and composition are stable under different weighting schemes. There are still four genera (figs. 102–103), however, which position in the tree changes depending on the weighting scheme—Thoracothropis (fig. 24), Gracilileia (fig. 25), Trichoterga (fig. 26), and Paracycloneura (fig. 30). We want to make this particularly clear, keeping these genera unplaced in the tribal system proposed for the subfamily. The problem of the position of these genera in our analysis is not due to missing data in the matrix. More probably there is an issue of a limited character sampling at these particular levels of the tree.

Thoracothropis is a monotypic genus known only from Chile (Freeman, 1951), more recently redescribed in detail (Oliveira et al., 2012) (fig. 24). The genus is indeed plesiomorphic for many features that characterize higher leiine clades. As mentioned above, Tozoni (1998) found Thoracotropis in the Gnoristinae. It could be the case that a wider sampling of gnoristine genera could move Thoracotropis out of the leiines. Gracileia is a genus endemic to New Caledonia, presently known from five species (Matile, 1993) (fig. 25). In our phylogeny this genus is sister to the clade Trichoterga⁺. Matile (1993) considered the similarities of Gracilileia with Tetragoneura (although the short, incomplete Sc directed toward bR in Gracilileia is similar to what is seen in some Manotini, see ahead). It is possible that Gracilileia indeed belongs in the Tetragoneurinae. Trichoterga is known only from New Zealand (Tonnoir and Edwards, 1927) and has a single species described (and some additional known undescribed species in collections). The genus is definitely not a typical higher leiine and its position more or less close to the base of the Leiinae should not be surprising. Jaschhof and Kallweit (2009) assumed that the genus very probably belong in the Leiinae. Finally, Paracycloneura has two described species from New Zealand—one described by Tonnoir and Edwards (1927) and one described more recently by Jaschhof and Kallweit (2009). The genus is actually quite apomorphic for some features and in our tree Paracycloneura is sister to the Rondaniellini⁺. Many of the features mentioned by Jaschhof and Kallweit (2009) shared among the genera of their Cycloneura group are absent in Paracycloneura. It could be the case that the genus is a Cycloneurini, but it would probably be necessary to have some more characters in the analysis to solve the question.

The Backbone of the Leiinae Phylogeny

If we remove the rogue taxa—Thoracotropis, Gracilileia, Trichoterga, and Paracycloneura—from the majority consensus tree, the main nodes of the backbone of the Leiinae phylogeny are the clades Megophthalmidiini⁺, Rondaniellini⁺, Cycloneurini⁺, Manotini⁺, and Anomalomyiini⁺, with the Selkirkiini sister of the remainder of the subfamily (figs. 99, 101–105). When these genera are removed from the tree, characters of the nodes below and above each genus are brought together as synapomorphies of the same node. This increases the number of characters, e.g., for the Megophthalmidiini⁺ and for the Rondaneillini+—but does not change the picture for the Cycloneurini⁺, the Manotini⁺, or the Anomalomyiini⁺.

The sequence of clades diverging along the backbone of the Leiinae does not particularly contradict the informal knowledge (i.e., not derived from a formal numerical analysis) about the group in the literature. The Selkirkiini is one of the least understood and least known groups of leiines. Restricted to a single Nearctic species and a clade with one species in Australia and a speciose clade in temperate South America, the Selkirkiini is sister to the clade with the set of other Leiinae groups in all trees recovered. The next clade is Megophthalmidiini (fig. 103). They are definitely not “core leiines” in their appearance, which may have been the reason for them to be moved in and out of the Leiinae by different authors. The following clade is Rondaniellini, which looks slightly more typical of higher leiines (fig. 103). The strict consensus has Rondaniellini, Cycloneurini, and (Manotini + Anomalomyiini + Leiini s.s.) in a polytomy. The Cycloneurini appears next (fig. 104), as sister of (Manotini + Anomalomyiini + Leiini s.s.). Finally, there is good support for the Manotini (fig. 105) to be sister to a clade including Anomalomyiini and Leiini (fig. 106).

Unique to the Megophthalmidiini⁺ is the displacement of the foramen magnum (char. 2:1), a feature with a single origin in Leiinae evolution, and a secondary loss in the group Sticholeia⁺ (= Manotini except Leiella) and in the clade (Neoclastobasis + Greenomyia). Another interesting feature is the flattened hind femur (char. 71). This feature is part of what may be referred to as the “leiine look.” The first apomorphic condition of this character is shared by all members of the group Megophthalmidiini⁺ and Gracilileia (with some secondary losses), with a further change to “strongly flattened” in some subgroups.

A Tribal Rank System for the Leiinae

We present below the clades in our tree to which we attribute tribal rank. Diagnoses are provided for each group, as well as their generic composition, geographical distribution, and a discussion of the relationships among their genera. Four of the seven clades accepted here as tribes already had tribal status given before in the literature.

FIGS. 64–65.

Male terminalia of Leiinae Selkirkiini genera. 64. Garretella shermani (Garret), dorsal view. 65. Paraleia nubilipennis (Walker), ventral view.

FIGS. 66–69.

Male terminalia of Trichoterga and of Megophthalmidiini genera. 66. Trichoterga monticola Tonnoir, dorsal view. 67. Megophthalmidia divergens Edwards, dorsal view. 68. Mohelia matilei Oliveira, dorsal view. 69. Aphrastomyia cramptoni Coher and Lane, ventral view.

FIGS. 70–71.

Male terminalia of Rondaniellini genera. 70. Indoleia bisetosa Edwards, ventral view. 71. Rondaniella dimidiata (Meigen), ventral view.

FIGS. 72–75.

Male terminalia of Cycloneurini genera. 72. Tonnwardsia aberrans (Tonnoir), lateral view. 73. Procycloneura paranensis Edwards, lateral view. 74. Procycloneura similis Freeman, ventral view. 75. Procycloneura similis Freeman, dorsal view.

FIGS. 76–79.

Male terminalia of Manotini genera. 76. Leiella unicincta Edwards, ventral view. 77. Leiella unicincta Edwards, dorsal view. 78. Allactoneura argentosquamosa (Enderlein), dorsal view. 79. Allactoneura argentosquamosa (Enderlein), ventral view.

FIGS. 80–81.

Male terminalia of Manotini, Eumanota wolffae Amorim, Oliveira, and Henao-Sepúlveda. 80. Ventral view. 81. Dorsal view.

FIGS. 82–83.

Male terminalia of Anomalomyiini genera. 82. Ateleia spadicithorax Skuse, dorsal view. 83. Acrodicrania fasciata Skuse, ventral view.

FIGS. 84–87.

Male terminalia of Leiini genera. 84. Leia ventralis Say, ventral view. 85. Leia ventralis Say, dorsal view. 86. Neoclastobasis draskovitsae Matile, ventral view. 87. Greenomyia stackelbergi Zaitzev, ventral view.

FIGS. 88–91.

Male terminalia of Leiini genera. 88. Clastobasis alternans (Winnertz), ventral view. 89. Clastobasis tryoni Skuse, ventral view. 90. Clastobasis stylata Matile, ventral view. 91. Clastobasis stylata Matile, lateral view.

FIGS. 92–95.

Male terminalia of Leiini genera. 92. Leia bivittata Say, dorsal view. 93. Leia andirai Lane, ventral view. 94. Leia fascipennis Meigen, dorsal view. 95. Leia winthemi Lehmann, ventral view.

Male Terminalia Patterns in the Leiinae

We address in this section male terminalia patterns that can be recognized in the Leiinae genera or groups of genera. Characters 121–128 in our list (appendix 1) refer to male terminalia features. Features of the terminalia most often referred to in published papers are: the size and shape of the gonocoxites, fusion of the gonocoxites medially at the ventral face of the terminalia, presence of gonocoxite lobes and projections and presence of modified setae and spines on the gonocoxite; place of insertion of the gonostylus on the gonocoxite and size, shape, and presence of setae and spines on the gonostylus; size, shape, and position of tergite 9 and, in some particular cases, presence of tergite 9 lobes and setation; and size, placement, shape, and position of the cerci. There is large variation of the size, shape, and degree of sclerotization of the parameres and the aedeagus, the size and placement of their apodemes and of the gonocoxal apodemes, as well as the size and degree of sclerotization of the sternite 10. These features are not known well enough across the subfamily and less emphasis is given to these structures along the discussion below. This section is supposed to be particularly useful while dealing with fossils.

We tried to be consistent here with the morphological nomenclature for lobes and branches of the gonocoxites and gonostyli found in the literature. They should not, however, be taken as strictly correspondent to homology between different genera or tribes in the leiines. That will be correct in some some cases (e.g., the bladelike ventral branch of the gonostylus in Anomalomyiini and the Leiini), but not in others (e.g., the ventral-distal lobes of the gonocoxites in genera in different tribes). These lobes should be seen basically as topological descriptions.

In the Selkirkiini, the male terminalia of Garretella differs considerably from that of species of Paraleia. Vockeroth's (1980) original description of the genus has an illustration of the wing and a detailed general description of the species, but there are no illustrations of the male terminalia. In Garretella shermanni (Garrett), the gonocoxites have distally at the ventral face a lobe extending to the level of the tip of the gonostylus. The gonostylus is relatively small, with some elongate setae at a short basal expansion dorsally. The tergite 9 is indistinguishably fused laterally to the gonocoxites and the cerci are slightly elongate (fig. 64). In Paraleia, including the Australian species, P. fulvescens Tonnoir (Tonnoir, 1929: text-fig. 7), the gonocoxites have a long distal expansion dorsally beyond the base of the gonostylus, and the gonostylus is typically elongate, often falciform (Freeman, 1951: figs. 146–150; Oliveira and Amorim, 2012). Many species have a large number of spines scattered at the inner face of the dorsal expansion of the gonocoxites and there is a long spine distally at the inner face of the gonostylus. The gonocoxites are separate from each other at the ventral face of the terminalia. Details of the shape of the gonostylus vary considerably between species, as well as the shape of the aedeagus, the parameres, and the cerci (fig. 65).

The four rogue genera in our tree have quite divergent male terminalia patterns, as expected. As far as we are aware, there are only two known specimens of Thoracothropis cypriformis Freeman, the only known species in the genus, in entomological collections—the holotype and a specimen of the José Pedro Duret collection at the MNHN. The male terminalia is illustrated in Freeman (1951: fig. 156) and in Oliveira et al. (2012: figs. 7–10). The gonocoxites are relatively short, with a medial deep separation between them ventrally. The gonostylus is digitiform, with an elongate, pointed distal dorsal projection and a ventral distal projection with a tooth. The parameres have a long, thin extension twice as long as the terminalia itself, a unique feature in mycetophilids.

The male terminalia of all four known species of Gracilileia Matile were illustrated by Matile (1993: figs. 25–26, 28–32). The gonocoxites are fused to each other medially at the ventral face along the anterior two thirds of the terminalia. The medial area extends internally toward the aedeagal-parameral complex. The aedeagal-parameral complex is short except in G. tillierorum Matile, where its distal end projects between the gonostyles. In some species, the gonostylus is almost twice as long as the gonocoxite, with a complex, strongly sclerified, sometimes trifid basal lobes. In two species, the gonostylus is short but also bears a basal projection. Tergite 9 is well developed laterally and has a deep posterior medial incision, with short and wide cerci. As mentioned above, it may be the case that Gracilileia belongs in the Tetragoneurinae.

The male terminalia of Trichoterga monticola Tonnoir differ from that of other rogue genera and as well does not properly fit in the pattern of any of the tribes of Leiinae. Tonnoir and Edwards (1927: fig. 244) illustrated the terminalia in ventral view. We illustrate here (fig. 66) the terminalia in dorsal view. The gonocoxite is longer than wide and the terminalia has an overall elongate shape. The gonostylus has a pretty large basal branch ventrally and there is a row of short spines distally on the gonostylus. Tergite 9 is very short, with a pair of digitiform cerci touching together medially. The aedeagus is elongate, extending slightly beyond the midpoint of the gonocoxites (fig. 66).

The male terminalia of Paracycloneura apicalis Tonnoir was illustrated by Tonnoir and Edwards (1927: fig. 213) and in much more detail by Jaschhof and Kallweit (2009: figs. 71–79). The gonocoxites are complex, with spines and well-developed setae. The gonocoxites have three posterior lobes, of which the dorsal lobe has at its inner face a row of pointed macrosetae and scattered spinules. The gonostylus is simple, digitiform, not hardly sclerotized, with only fine setae. The tegmen of the aedeagal-parameral complex is subtriangular distally and the gonocoxal apodemes are typically short. Tergite 9 has a pair of developed lateral arms at the posterior margin projected beyond the tip of the gonostylus, with a deep incision between them. The cerci are placed at the distal margin of a membrane connecting the gonocoxal dorsoposterior lobes.

FIG. 96.

Majority consensus of the 119 most parsimonious trees obtained with equal weight, the taxa accepted as subfamilies in most classifications highlighted, as well as the Tetragoneura group ranked as a subfamily. The Gnoristinae generic sample in the analysis groups in two separate clades that do not conform a monophyletic group.

In the Megophthalmidiini, Megophthalmidia has a complex male terminalia, studied in detail by Kerr (2014) for Nearctic species. In most Nearctic and Palearctic species, the gonocoxite is elongate, with a dorsolateral distal expansion into which the proportionally small gonostylus fits. The gonocoxites may have a deep, slender gap between them medially or may entirely close the ventral face of the terminalia (as in Megophthalmidia divergens; fig. 67). Even though the gonostylus is relatively small, it can be quite complex, with branches, a strong sclerotized distal part and some additional ornamentation (also see Chandler et al., 2006). The internal parts of the terminalia are also complex, particularly the aedeagus (see Kerr, 2014). Tergite 9 may either be complex, the posterior margin having a pair of arms projected ventrally, or it may be short and slender. The cerci are not particularly modified. The elongate shape of the terminalia in most Holarctic species is not seen in some of the southern South America species (Lane, 1962: fig. 2), although the gonostylus is almost always considerably complex (see, e.g., Lane, 1954a: figs. 1–2)—our figure 67.

The male terminalia of Mohelia nigricauda Matile was illustrated by Matile (1978: figs. 35–36). In that species, the gonocoxites are large, projected laterodistally much beyond the tip of the aedeagus, with an elongate gonostylus that fits into the distal end of the gonocoxite, apparently bifid basally. The ventral face of the terminalia has the inner border of the gonocoxites close together, also seen in Megophthalmidia. Tergite 9 in M. nigricauda is short laterally and has a pair of projections more medially at the posterior margin. The aedeagus is subtriangular, tapering to the distal end, and the gonocoxal apodemes are well developed. In Mohelia matilei Oliveira (Oliveira, 2015: fig. 11A–D), the distal projection of the gonocoxite is much shorter (fig. 68), but in M. amorimi Oliveira and M. chandleri Oliveira the gonocoxite is large, with a laterodistal projection, as in M. nigricauda. Most species of the genus have a pair of conspicuous groups of setae on tergite 9. The bifid, usually complex gonostylus, is a feature shared by all species of the genus.

The male terminalia of Aphrastomyia have been carefully described and illustrated by Jaschhof and Kallweit (2004: figs. 7–17). The gonocoxites are fused medially at the anterior margin and the terminalia is wider than the gonocoxite length. The gonocoxite do is not project much beyond the base of the gonostylus and there are short ventral and dorsal distal lobes. The gonostylus is not particularly complex, but has a basodorsal lobe that gives, as in the remaining Megalophthalmiini, a general bifid shape to the gonostylus (fig. 69). In some species, the tergite 9 has a short projection on the posterior margin that may be slightly more sclerotized than the remainder of the sclerite and with a concentration of setulae. The cerci are typically small, rounded, and separate from each other.

Both genera of Rondaniellini have a similar, very complex male terminalia. This shared pattern supports the hypothesis of a clade connecting these two genera in a tribe Rondaniellini. There are no published illustrations of male terminalia of most species of Rondaniella and there is no published illustration of the terminalia of Indoleia. The terminalia of the Chinese species of Rondaniella were illustrated by Yu et al. (2004, 2008) and Yu and Wu (2009). Indoleia bisetosa (fig. 70) shares with Rondaniella dimidiata (Meigen), the type species of the genus (fig. 71), the slightly longer than wide gonocoxites, with a considerably wide sclerite medially between them at the ventral face of the terminalia. The posterior margin of the syngonocoxite ventrally at each side is slightly more sclerotized than the rest of the gonocoxite and bears a row of distinctive, longer setae. The gonocoxite does not project beyond the base of the gonostylus. The gonostylus is fairly complex, at least in some species with a dorsal lobe and a medial lobe in additional to the main gonostylar lobe. Some of the lobes of the gonostylus have only regular fine setae and some have combs of spines and groups of sclerotized, strong setae. The parameres are also strongly modified, with a distal comb of spines. The tergite 9 and the cerci have pretty standard shape and size.

FIG. 97.

Strict consensus of the 119 most parsimonious trees obtained with equal weight, the Leiinae highlighted. Bremer support indicated for nodes within the Mycetophilidae (the monophyly of the Mycetophilidae is the result of the a priori election of the keroplatid to root the tree).

Most genera of Cycloneurini have the male terminalia only slightly elongate, encapsulate, i.e., without appendages or parts projecting outside the terminalia. Jaschhof and Kallweit (2009) carefully illustrated the terminalia of Waipapamyia, Cawthronia, Sigmoleia, and Paradoxa. Tonnoir and Edwards (1927: figs. 236 –237) illustrated the terminalia of two species of Cycloneura. The male terminalia of Tonnwardsia has not been illustrated so far.

The male terminalia of Waipapamyia is fairly simple. The gonocoxites are relatively longer than wide, with a deep V-shaped medial incision between the gonocoxites that reaches the anterior margin of the terminalia ventrally. The gonostylus is more or less palmate in lateral view, with a hardly sclerotized distal tooth or spine and with some strong setae, with details varying among species of the genus. Tergite 9 has a pair of extensions at the posterior margin, each projection having a pair of long setae apically (Jaschhof and Kallweit, 2009: figs. 90–93, 97–103). The aedeagus is standard, with a tegmen distally, sided by a pair of elongated parameres that connect to each other, extending anteriorly into the parameral apodemes.

The male terminalia of Cawthronia (Jaschhof and Kallweit, 2009: figs. 80–85, 88) is also simple, in a certain extant similar to that of Waipapamyia. The incision between the gonocoxites ventrally is not as deep, while the gonostylus is also slightly palmate, but without any ornamentation other than the distal tooth. Tergite 9 is subtriangular, almost trapezoid, while the parameres are reduced to a pair of apodemes connected medially. As in Waipapamyia, the gonostylus has a distal position on the gonocoxite.

In Sigmoleia (Jaschhof and Kallweit, 2009: figs. 55–58, 63–64, 65–67, 69–70), the general shape of the terminalia is also slightly elongate, but the gonocoxite has a long, digitiform extension lateroventrally ending beyond the tip of the gonostylus, with a distinctive distal short seta. The distal lobe of the gonocoxite partially covers the gonostylus. The gonostylus has a short basal stalk, with a large body arising from it; the enlarged distal part of the gonostylus is ornamented with a number of spines at its inner face. The gonocoxal apodemes are fairly elongate. The aedeagus is subtriagular or subquadrate distally, with a pair of apodemes extending laterally at the anterior end. Tergite 9 is more or less rectangular, with a pair of short lobes on the posterior margin or entirely divided into a pair of lobes.

The male terminalia of Paradoxa is about as long as wide. The gonocoxite has a dorsolateral extension beyond the base of the gonostylus, the tip of the gonocoxite and of the gonostylus ending at about the same level. There is a deep incision between the gonocoxites, almost reaching the anterior end of the terminalia ventrally, quite wide at the distal margin. The gonocoxite in P. fusca, the type species of the genus, from New Zealand, has an additional short lobe at the inner face, dorsally to the base of the gonostylus, bearing scattered short spines (Jaschhof and Kallweit, 2009: figs. 45, 47, 50–51). In P. paradoxa, from southern Africa, the gonocoxite also has short spines along the inner face of the distal projection dorsally to the gonostylus (Jaschhof, 2006: figs. 5, 7–9). The gonostylus can be seen in ventral view in both species. In P. fusca, it is elongate, more or less flattened, without distal lobes; in P. paradoxa, the gonostylus is digitiform, with three short distal lobes and one elongate distal spine on one of the lobes. The parameres have the typical H-shape, with a pair of slender blades projecting distally and a pair of parameral apodemes projecting anteriorly, with a medial connection between them. The aedeagus is cylindrical, elongated distally. Tergite 9 is rectangular, much longer than wide, the distal margin reaching the level of the tip of the gonocoxites.

FIG. 98.

Resulting tree of the analysis with implicit weight with k = 3, the Leiinae highlighted. The Tetragoneurinae appears as sister of the Leiinae plus the clade (“Gnoristinae” + Mycomyinae + Mycetophilinae).

The male terminalia of Cycloneura has more or less elongate gonocoxites. In C. flava, the gonocoxites are connected at the ventral face of the terminalia along the anterior half, diverging distally; in C. triangulata, gonocoxites are more or less parallel and connected along the anterior three fourths of the terminalia (Tonnoir and Edwards, 1927: figs. 236–237). There is a short projection of the posterior border of the gonocoxite ventrally in C. triangulata, extending slightly beyond the base of the gonostylus. The gonostylus is quite short in both species, distally much wider than at the base, especially in C. flava, and there are scattered short spines at the inner face of the gonostylus.

In Tonnwardsia, the terminalia is rather compact and also has the gonostylus inserted at the distal end of the gonocoxite. There is a pair of elongate, bifid processes emerging quite anteriorly at the inner margin of each gonocoxite. The gonocoxites apparently are indistinguishably fused laterodorsally to the tergite 9. The gonostylus is simple, elongate, bent at the basal third, without spines, but with a basal, bladelike ventral lobe. The aedeagal-parameral complex is elongate and sclerotized. The cerci are largely in contact medially (fig. 72).

Edwards (1932, 1933) did not illustrate the male terminalia of both Procycloneura species he described, but there are good illustrations of the Chilean species in Freeman (1951: figs. 154–155). In this genus, the male terminalia is rather compact. The gonocoxites are separated by a deep V-shaped incision that reaches the anterior end of the terminalia. In some species, there is a pair of short, digitiform projections emerging medially at the inner border of the gonocoxites. There is also a short projection of the gonocoxite dorsally extending beyond the base of the gonostylus. The gonocoxites have at the inner face of the distal border dorsally modified short spines. The gonostylus is typically falciform, but details of the shape and size of the gonostylus vary considerably between species. In some species, the basal part and the distal part of the gonostylus have similar length, while in others the basal section is much longer than the curved distal section. The gonostylus distally may have long setae and a comb of spines. The tegmen is slender distally. Tergite 9 is as long as the gonocoxites dorsally, with some stronger setae at the distal margin (figs. 73–75).

The Manotini have a wide array of male terminalia patterns, much more diversified than seen in the Cycloneurini. Leiella is quite conservative, with more or less encapsulated terminalia. In several papers Lane provided illustrations of L. unicincta (1952: fig. 5; 1954b: fig. 1), of L. catharensis, L. fulva, and L. shannoni (1954b: figs. 2–4), and of L. arnaudi (1962: fig. 4). The gonocoxite is slightly longer than wide and extends laterally only slightly beyond the base of the gonostylus. The gonocoxites are fused to each other along the entire medial line ventrally. The distal end of the gonocoxites laterally may have a row of strong setae or spines. The gonostylus is small, slightly elongate, with combs of small spines, in some species also with a strong distal spine. The aedeagal-parameral complex is modified, with a wide tegmen and wide parameral blades. The gonocoxite dorsal margin is well developed and tergite 9 is slender, elongate, with some few strong setae at the posterior margin. The cerci are hardly visible (figs. 76–77).

Both known species of Sticholeia have a unique male terminalia pattern, which were carefully described and illustrated by Søli (1996, 2002a). They have extremely elongate cerci and lateral extensions of the gonocoxites that are equally long (interpreted as extensions of tergite 9 by Søli, 1996, 2002a). The gonocoxites are fused medially to each other along the entire ventral face. The gonocoxite extensions are from nearly three to five times the length of the body of the terminalia itself. The gonocoxites have a long row of slender spines placed along the inner face of the distal half of the gonocoxite extension. The syngonocoxite ventrally has a pair of projections with a long seta at the apex and two additional digitiform lobes of the gonocoxite at each side, close to the base of the gonostylus. The gonostylus is small, elongate, slightly bent midway to apex, slightly widened distally, with only a few fine setae. The aedeagus is subtriangular, quite slender distally. The parameres are not easy to recognize, but they seem to be wide and laminar. Tergite 9 is reduced to a small sclerite between the dorsal borders of the gonocoxites dorsally, at the base of the cerci. The cercus is thin and elongate, with long, curved setae on its internal face along its entire length. This pattern is unique among the leiines.

FIG. 99.

Resulting tree of the analysis with implicit weight with the setk script value of k = 24.22175, the Leiinae highlighted. The Tetragoneurinae appears as sister of the Leiinae and (“Gnoristinae” + Mycomyinae + Mycetophilinae) appears as sister of (Tetragoneurinae + Leiinae).

FIG. 100.

Phylogenetic classification of the Leiinae, with indication of clades to which tribal rank was given (majority consensus of the 119 most parsimonious trees obtained with equal weight analysis).

FIG. 101.

Character distribution in the tree with the relationships among Mycetophilidae subfamilies in the majority consensus of the 119 most parsimonious trees obtained equal weight analysis.

FIG. 102.

Character distribution in the tree of the relationships in the majority consensus of the 119 most parsimonious trees obtained with equal weight analysis, the Megophthalmidiini⁺ as a terminal.

FIG. 103.

Character distribution in the tree of the Megophthalmidiini⁺ in the majority consensus of the 119 most parsimonious trees obtained with equal weight analysis, the Cycloneurini⁺ as a terminal.

FIG. 104.

Character distribution in the tree of the Cycloneurini⁺ in the majority consensus of the 119 most parsimonious trees obtained with equal weight analysis, the Manotini⁺ as a terminal.

FIG. 105.

Character distribution in the tree of the Manotini⁺ in the majority consensus of the 119 most parsimonious trees obtained with equal weight analysis, the Anomalomyini⁺ as a terminal (habitus of Eumanota wolffae, photo Andrea Carolina Henao-Sepúlveda).

FIG. 106.

Character distribution in the tree of the Anomalomyini⁺ in the majority consensus of the 119 most parsimonious trees obtained with equal weight analysis.

There are good illustrations of the male terminalia of Allactoneura in the original descriptions of species, but without much discussion on homology of the sclerites of its complex male terminalia. Bechev (1995: figs. 1–2) included illustrations of the terminalia in lateral view and of the tip of the gonostylus of A. papuensis. Zaitzev (1982a) has illustrations of the male terminalia of A. ussuriensis Zaitzev, A. formosa (Enderlein), and A. cincta de Meijere in lateral view (respectively figs. 1.1, 2.2, 3.1) and of the tip of the gonostyle in lateral view (figs. 1.6, 2.3, 3.2) and the of the terminalia of A. cincta in ventral view (fig. 2.1). Sasakawa (2005: figs. 6–7) illustrated the male terminalia of A. akasakana Sasakawa in lateral view and in ventral view, respectively. The most important discussion on the homology of the male terminalia was made by Søli (1997, fig. 33B). The male terminalia in Allactoneura is rotated, meaning that the gonocoxites are largely developed, occupying the entire original ventral face of the terminalia, extending far beyond the level of the tip of the cerci. The gonostyli are displaced dorsad and partially articulating directly to tergite 9. The gonostylus is about as long as the gonocoxites or longer. The aedeagal-parameral complex is rectangular, well sclerotized, and also elongated, about half the length of the gonocoxites. Tergite 9 is always relatively small at the original dorsal face of the terminalia, placed anteriorly to the base of the gonostylus. The cerci are small, slightly elongate, placed medially at the posterior margin of tergite 9 (figs. 78–79). There is an Oligocene fossil of this genus known from France (Théobald, 1937). A fossil specimen of a male belonging to a species of the crown group of the genus is not difficult to recognize.

The male terminalia of four species of Eumanota were carefully described and illustrated by Søli (2002b: figs. 5–19), while Papp (2004: figs. 1–8) described and illustrated the terminalia of two species of the genus. Hippa et al. (2005) redescribed the terminalia of E. leucura (fig. 5C, D) and of two additional species (figs. 4B, 5A, B). More recently, Amorim et al. (2018) included detailed illustrations of the terminalia of the Neotropical species of the genus, E. wolffae Amorim, Oliveira, and Henao-Sepúlveda, from Colombia. The gonocoxites of Eumanota species are fused medially along at least part of the ventral face of the terminalia. There are some projections at the posterior margin of the gonocoxites ventrally and laterally. The tip of the gonocoxite in some species extends beyond the base of the gonostyle laterally. The gonostylus may be digitiform, club shaped or with ornamentation, only with fine setae or with some few additional stronger setae. The aedeagus may be tubular distally and the parameres may be ornamented. Tergite 9 is trapezoid, elongate, with well-developed cerci placed distally (figs. 80–81).

In a good extension, the general pattern of the male terminalia of Eumanota applies to Promanota. In Promanota, the terminalia is more or less elongate, encapsulate, the trapezoid tergite 9 with well-developed cerci placed at its posterior margin. In both known species of Promanota, the gonocoxite extends laterodistally to the level of the tip of the gonostylus (Tuomikoski, 1966: figs. 1–2; Hippa et al., 2005: figs. 6a–c; Papp, 2004: figs. 9–12).

FIG. 107.

Majority consensus equal-weight tree overlapped to present distribution of leiines (top) and phylogenetic placement of mycetophilid fossils (open circles), with nonleiine terminal species collapsed into subfamilies and leiine species into genera. Temperate Gondwanan terranes (blue) make clear seven clades (numbered arrows) of secondary biotic expansions to more northern distributions. NZ = clades with exclusive New Zealand distribution, placed on a time line corresponding to its separation from remaining Gondwanan terranes, ∼80 Ma. Circled numbers at left correspond to fossil deposits (appendices 4, 5).

This pattern of the male terminalia of Paramanota is quite divergent from these other two Manotini genera. In Paramanota, the gonocoxites are well-developed laterally but are separated medially by a wide membranous area, in some species covering almost entirely the ventral face of the terminalia. Hippa (2010: 48) mentioned that the ventral lobe in Paramanota is similar to “sternite 9” in Manota (e.g., Hippa, 2009: fig. 2 d)—except for the fact that the gonocoxites in Paramanota are divided ventrally into these two separate halves. It is interesting to note that, as happens with in the wing venation, there are some derived similarities in male terminalia features shared between Paramanota and Manota. Paramanota orientalis Tuomikoski, the type species of the genus, shows the gonocoxites largely developed ventrally (Tuomikoski, 1966: figs. 3–4; Hippa, 2010: figs. 5C–E). From a dorsal view, it is possible to see spines at the inner face of the gonocoxites. The gonocoxites may have a digitiform projection of the posterior margin of gonocoxite laterally at its ventral face, as in P. bifalx Hippa (Hippa, 2010: fig. 2C–D), medially, as in P. furcillata Hippa (Hippa, 2010: fig. 3D) and P. schachti Papp (Papp, 2004: fig. 29), or at an inner face, as in P. orientalis (Hippa, 2010: fig. 5D), in P. awanensis Hippa et al. (2005: fig. 9a, b) and P. sumatrana Hippa et al. (Hippa et al., 2005: fig. 11a). Neither P. rodzayi Hippa et al. or P. trilobata Hippa et al. (Hippa et al., 2016: figs. 1A–D, 2A–C) have the distal-lateral digitiform extension of the gonocoxite. The gonostylus is small compared to the gonocoxite and is particularly complex, with branches and a comb of spines. The aedeagus and the parameres are fused together, forming a subquadrangular, slightly elongate sclerite—details of the aedeal-parameral complex vary among species. Tergite 9 is subquadrate, with the cerci well developed, visible distally in P. schachti Papp (Papp, 2004: figs. 26–30). The fossil P. grandaeva is a female, so male terminalia features cannot be verified in the holotype. In its own way, this is also a unique male terminalia pattern in the Leiinae.

There are now over 300 described species of Manota worldwide (Kurina et al., 2019), with an important number of photos and illustrations of the male terminalia. There is considerable variation on the morphology of different sclerites of the male terminalia in the genus. It can be fairly simple, as in Manota ctenophora Matile (Matile, 1993: figs. 65–66), or quite complex, e.g., as in M. palpalis Lane (Kurina et al., 2018: figs. 22B, C), in which the gonocoxite has a parastylar lobe, a medial lobe, a large platelike lobe and a posterolateral lobe, ornamented with juxtagonostylar megasetae, spathulate subapically geniculate megasetae, the gonostylus having a lateromedial expansion, a subapical digitiform lobe and a subapical ventral small lobe with twisted setae. In a large number of species, the gonocoxites are separate medially, with a sclerite in between (referred to as sternite 9). This sclerite is smaller in some species and considerably well developed in others (e.g., M. peltata Kurina and Hippa (Kurina and Hippa, 2014). The gonocoxites in some cases extend much beyond the tip of the gonostylus (as in M. carioca Kurina, Hippa and Amorim) or may end almost at the level of the insertion of the gonostylus (e.g., M. hirta Kurina, Hippa and Amorim). The gonostylus is usually small, but with different kinds of ornamentation—i.e., branches and setae. In some few species, as in M. forceps Hippa and Papp, the gonostylus is largely developed. The aedeagus is often elongate, subtriangular, with or without lateral shoulders. The aedeagal apodemes can be recognized, but the aedeagal-parameral complex is not particularly sclerotized or easy to be identified. Only some few species have a recognizable tergite 9 (e.g., M. atlantica) and in most descriptions tergite 9 is not even mentioned; it is usually fused to the gonocoxite at the lateral margins. The cerci are present in a more distal position in the terminalia dorsally, usually elongate and close to each other. Most recent papers describing species of Manota from the Oriental (Hippa and Papp, 2007; Hippa and Ševčík, 2010; 2013; Hippa and Saigusa, 2016; Hippa and Kurina, 2018;), Afrotropical (Jaschhof and Mostovski, 2006; Hippa, 2008; Hippa and Kurina, 2012; Kurina and Hippa, 2014), Neotropical (Jaschhof and Hippa, 2005; Hippa and Kurina, 2013; Hippa et al., 2017; Kurina et al., 2017, 2018), Australian (Hippa, 2007; Jaschhof and Jaschhof, 2010; Ševčík et al., 2014; Kurina and Hippa, 2015) and Holarctic (Jaschhof et al., 2011) regions are richly illustrated.

In the Anomalomyiini, the shape of the male terminalia largely fits into a general mycetophilid standard, but some details are shared among the three genera of the tribe (fig. 82–83). In Anomalomyia, the gonocoxites together are V-shaped, with a deep and wide separation between them ventrally, connected medially only at the anterior end of the terminalia (Tonnoir and Edwards, 1927: figs. 232–235; Matile, 1993: figs 2–3). The gonostylus is placed distally at the gonocoxite, i.e., there are no gonocoxites lobes projecting beyond the base of the gonostylus. The gonostylus is complex, with a large variation between the species. There are three basal lobes on the gonostylus, with combs of spines, setae, and scattered spines. The ventral lobe is consistently bare, bladelike. The parameres have a distal projection extending beyond the tip of the tegmen. Tergite 9 is fused laterally to the gonocoxites.

There are no illustrations of Ateleia in the literature to date. The male terminalia of Ateleia are considerably similar to that of Anomalomyia. The gonocoxites are also widely separated ventrally. The gonostylus is basically digitiform, with some short basal lobes, including a bladelike, bare ventral lobe. There is a small comb of spines distally on one of the lobes and there are scattered short spines at the inner face of the gonostylus distally. Tergite 9 is also fused to the gonocoxites laterally (fig. 82).

The male terminalia of Acrodicrania is slightly more complex, but the changes are relatively minor in relation to the pattern seen in the other two genera of Anomalomyiini. A. fasciata Skuse has a row of strong setae along the inner margin of the gonocoxite at the ventral face of the terminalia, but this is lacking in other Australian species or in A. africana Edwards, the type species of the genus. The gonostylus is placed at the distal end of the gonocoxite and has basal lobes, as in the other two genera of Anomalomyiini; the ventral lobe is also bare and bladelike, the other two with comb of spines and strong setae. The inner face of the main lobe of the gonostylus has scattered shorter spines. The aedeagus is cylindrical, the distal third more slender than the proximal two thirds. The parameres extend beyond the tip of the aedeagus and have fine and strong setae distally (fig. 83). There are no published illustrations of the male terminalia of any of the four Australian species, the Afrotropical species or the three Oriental species of Acrodicrania.

The Leiini have some variation of male terminalia general format and of the shape and ornamentation of their sclerites as well (figs. 84–95). The only known species of Caledonileia has features (Matile, 1993: figs. 21–22) that make its placement within the Leiini likely. The gonocoxites are quite separate medially on the posterior two thirds of the terminalia at the ventral face and are fused together on the anterior third. The syngonocoxite extends itself medially toward the aedeagal-parameral complex, a condition similar to that seen in Neoclastobasis (fig. 86). The gonostylus is suboval, with a pair of basal lobes, the ventral one bladelike and bare, the dorsal one digitiform, with a comb of spines. Indeed, the basal lobes of the gonostylus in Caledonileia are similar to those in Neoclastobasis (fig. 86) and in Greenomyia (fig. 87), and much as in the genera of Anomalomyiini (figs. 82–83). The distal end of the aedeagal-parameral complex is well sclerified dorsally. The aedeagal apodeme extends anteriorly to reach the segment VIII. Tergite 9 cannot be recognized dorsally and seems to be entirely fused laterally to the dorsal borders of the gonocoxites.

It is worth considering the male terminalia of Leia ventralis separate from the rest of the species of Leia (figs. 84, 85) and Clastobasis (figs. 88–95). The gonocoxites are largely fused together along the anterior half of the terminalia ventrally and there is no suture of the fusion or evidence of a medial syngonocoxite sclerite. Each gonocoxite extends laterally beyond the medial posterior margin of the syngonocoxite, with the gonostyli placed apically at each gonocoxite. There is a pair of very large spines (apparently articulated into sockets) at the posterior margin of the syngonocoxite medially. The gonostylus is relatively simple, with a main lobe wider at base that becomes slender toward the apex, but also with basal lobes. There are scattered setae on the gonostylus and a long, stronger seta at the apex. The parameres are well developed and sclerotized, apparently with a pair of protuberances with short dark spines ventrally on the internal margins. The gonocoxal apodemes are well separated. Tergite 9 is elongate, separate laterally from the dorsal borders of the gonocoxites. The differences between the male terminalia of L. ventralis and those of other species of Leia and of Clastobasis, Neoclastobasis, Greenomyia, and Caledonileia suggest that this species may belong to a separate genus.

Neoclastobasis has more open male terminalia, with a clear V-shape of the syngonocoxite (Matile, 1978: figs. 1–2; Zaitzev, 1982b: figs. 2.4–6, 3.1–3). The gonocoxites are connected together medially on their basal third and there is a conspicuous distal extension of the gonocoxite at the ventral face, partially covering the base of the gonostylus. The gonostylus is palmate, with a pair of elongate lobes basally, the ventral one bare and bladelike and the other one with a group of distal short spines. The entire inner face of the main body of the gonostylus is covered with dense, stiff setae. The aedeagal-parameral complex is subquadrate, sclerotized distally. The cerci are projected dorsally slightly beyond the tip of the aedeagus (fig. 86).

In Greenomyia, the terminalia is slightly longer than wide and the gonostylus is also placed distally at the gonocoxite (Zaitzev, 1982b: figs. 1.1–2, 2.1–2; Matile, 2002: figs. 1–3). The gonocoxites with few exceptions are not in contact medially except close to the anterior margin of the terminalia. In most cases, there is a distal extension of the gonocoxite internal margin, which shape varies among species. The gonostylus is complex, subquadrate, with a bladelike, bare ventral lobe and a dorsal lobe with strong apical setae; the main body of the gonostylus has elongate setae along the distal margin and a comb of spines at the inner face. Dorsally, the gonocoxites are fused to tergite 9. The cerci extend at least to the level of the base of the gonostylus (fig. 87).

Taxon sampling here was designed to generate phylogenetic information along the Leiinae backbone, and seems adequate to demonstrate that the Leia-Clastobasis complex corresponds to a clade within the tribe Leiini. The sampling of species within each of these genera, however, is not enough to provide a full solution for the relationship within the clade with these two genera. Because understanding of homology is largely illuminated by hypotheses of phylogeny, not solving the problem of the paraphyly or polyphyly of these two genera weakens our attempts to solve some of the issues of homology concerning male terminalia in the clade.

We can distinguish morphologically two main patterns in the clade—a “standard Leia pattern” and a “standard Clastobasis pattern.” There are species in either genera, however, that clearly do not fit well into either of the patterns and there are species that combine some of the features in both patterns. The terminalia in both genera are considerably wide in lateral view due to the gonocoxite well developed along its ventral-dorsal axis. The standard Leia pattern can be recognized by the aedeagal-parameral complex with a well-sclerotized “arrow-headed” distal end, quite easily recognizable in the terminalia of many species, with a considerably simple gonostylus. This is the condition seen in the type species of the genus, Leia fascipennis (fig. 94). The usual Clastobasis pattern has a well-developed medial syngonocoxite sclerite, often bifid, in some species projecting beyond the tip of the laterodistal end of the gonocoxite, with the gonostylus often quite developed, as in the type species of the genus, Clastobasis tryoni Skuse (fig. 89). There are, however, species of Clastobasis with a well-sclerotized aedeagus distal end—as in C. alternans (Winnertz) (Chandler, 2001: figs. 15, 17) (fig. 88)—and species of Leia with a well-developed medial syngonocoxite sclerite projecting posteriorly—as in L. flavipennis Laštovka and Matile and L. rufiptera Ostroverkhova (Polevoi and Salmela, 2016: figs. 1 and 5, respectively). This seems to reinforce the hypotheses that both genera are paraphyletic or polyphyletic to each other.

In Clastobasis, the general shape of the male terminalia in most species is encapsulated, similar to that of most Leia. The medial sclerite of the syngonocoxite, however, is conspicuous in most species and is sometimes bifid distally, e.g., Clastobasis alternans (Winnertz) (Chandler, 2001: figs. 15–17) and C. tanganyikae (Matile) (Matile, 1973: fig. 8), but also may be absent, as in C. tryoni. In some groups of species, there is a posterior extension of the gonocoxite ventrally, e.g., C. tryoni (fig. 89) and C. alternans (Chandler, 2001: figs. 15–17), or dorsally, e.g., C. maculicoxa Matile (Matile, 1978: fig. 37), with concentrated spines or modified setae. The gonostylus in some species is particularly long, as in C. stylata Matile (Matile, 1993: fig. 16), but in most Clastobasis species the gonostylus is much smaller, as in C. loici Chandler (Chandler, 2001: figs. 18–20). The gonostylus in some cases has branches or lobes, as in C. brunhesi Matile (Matile, 1993: fig. 40), but in many cases it is rather simple, “Leia-like” in size and shape, as in C. alternans. An aedeagal-parameral complex that distally is hardly sclerotized is seen, for example, in C. alternans, C. villiersi Matile, C. tryoni, C. stylata, C. loici, etc. The length and shape of tergite 9 and the cerci varies considerably between species (figs. 88–91).

Leia fascipennis Meigen was carefully illustrated by Kurina (2008: figs. 27–30) and L. winthemi Lehmann was illustrated by Søli (1997: fig. 31A) (fig. 94). There are additional good illustrations of species of Leia, e.g., in Polevoi and Salmela (2016). In many species of Leia, the gonocoxites are about twice as long as wide in ventral view. The inner and outer margins of the gonocoxite ventrally are more or less parallel to each other in most species and many species have a medial process projecting between the gonocoxites. The shape and the length of this process is considerably variable. The gonostylus is well sclerotized and elongate in most species, and at rest it more or less fits across the distal end of the terminalia as a lid on each side (Kurina, 2008: fig. 28). There are species in which the gonostylus is not digitiform and assumes other shapes, e.g., subtriangular, bifid, etc. Only rarely Leia species have modified, spinose setae on the gonostyle, having at most elongate fine setae. Apparently, no species of Leia has a basal, bladelike projection of the gonostylus, as seen in Greenomyia and in Neoclastobasis. If we assume that this blade is a synapomorphy of the Anomalomyiini⁺, the condition in Leia would be due to a secondary loss of this blade. Tergite 9 is largely independent from the gonocoxites laterally, usually trapezoid and elongate. In some cases, a pair of slightly elongate cerci project beyond the level of the base of the gonostylus. The parameres are connected anteriorly and project beyond the distal end of the well-sclerotized aedeagus (figs. 92–95). In some species, as L. nigricornis van Duzee, this typical enclosed shape of the male terminalia is not seen (Polevoi and Salmela, 2016: figs. 4A–C).

Key for the Genera of Leiinae

An identification key for the genera of Leiinae as delimited here is included below. This key is largely modified from Vockeroth (1981, 2009) and Søli et al. (2000). Abbreviation for geographical distribution of genera as follows: PA, Palaearctic Region; NE, Nearctic Region; OR, Oriental Region; AF, Afrotropical Region; NT, Neotropical Region; AU, Australasian/Oceanian Region.

Mesozoic Fossil Record of the Leiinae

The phylogenetic analysis of the Leiinae in this paper provides not only hypotheses of relationships for the subfamily, but also a more rigorous basis for fitting fossils into the framework of evolution of the group. Cenozoic fossils of Mycetophilidae basically belong to the Recent genera or are sister clades to Recent genera. The Cretaceous genera, however, clearly belong to the early diversification of mycetophilid clades—much harder to precisely place into the classification of living genera, but particularly informative about the evolution of the group.

The most important published paper in this context is Blagoderov and Grimaldi's (2004) study of sciaroids from six major early to late Cretaceous amber deposits—Lebanon (ca. 125 Ma), northern Spain (ca. 105–108 Ma, Albian), northern Myanmar (98–99 Ma), northern Siberia (134–131 Ma, ca. 100 Ma, and 90–94 Ma), New Jersey (90–94 Ma), and western Canada (ca. 78 Ma).

Blagoderov and Grimaldi (2004) described species related to the Sciophilinae, the Gnoristinae, the Manotinae, and the Leiinae (as tribes of Sciophilinae s.l., in their system)—with the tetragoneurine genera considered leiines. Most of the species described in their paper belong to extinct genera, but some species fit into extant genera: the sciophiline Neuratelia Rondani and Allocotocera Mik, the gnoristine Apolephthisa Grzegorzek, Synapha Meigen, Dziedzickia Johannsen, Saigusaia Vockeroth, and Syntemna Winnertz, and the tetragoneurine Ectrepesthoneura. Blagoderov (1997, 1998a, 1998b, 2000) described an important number of Lower and Upper Cretaceous, and Paleocene compression fossils from Transbaikalia and Siberia in Russia, and from Mongolia. There are also compression and amber mycetophilids from the Lower Cretaceous of Spain (Blagoderov and Martínez-Delclòs, 2001; Blagoderov and Arillo, 2002).

Most described Cretaceous fossils are clearly sciophilines and gnoristines, but an important number can be assigned especially to the tetragoneurines and some to the leiines. We consider below each of the Cretaceous genera assigned to the leiines, manotines, and tetragoneurines, and discuss the phylogenetic and biogeographical implications of these fossils. We do not intend this to be an extensive taxonomic treatment of these fossils. This is rather an effort, relying on the original descriptions and using our phylogenetic analysis as a framework, to better interpret the biogeographical evolution of the Leiinae. This will be useful to calibrate molecular phylogenies in the future. All known mycetophilid fossils are added to the phylogeny in figure 107, overlapped with biogeographical information and a temporal scale.

Biogeographic Evolution of the Leiinae

Understanding the history of the geographical distribution of animals and plants is one of the most challenging areas of the biological sciences. The reason is twofold: first, it demands a large amount of technically precise data, not often available; and second, biogeographical evolution itself is an extremely complex process that masks over time original distribution patterns–it involves successive events of vicariance, biotic expansion, biotic overlap, reiteractive barriers, replicated patterns, extinction, individual dispersal across preexisting barriers, and so on. Besides, there are methodological issues that add up to the complexity of the evolutionary process, including incongruous patterns, taxonomic and geographic undersampling, and limitation of many of available algorithms, to name a few.

The enthusiastic optimism over biogeography in the 1980s turned more recently to the other extreme, with considerable skepticism about the possibility of fully recovering the biogeographical evolution of areas and taxonomic groups. The extent of conflicting analytical approaches led Nelson and Ladiges (2001) to refer to a “mess of methods” in biogeography.

One of the major problem concerns the divergence between cladistic ages inferred through a bigeographical approach versus those inferred through other sources of data—fossils, molecular clocks, etc. In some groups of flies, for example, an interpretation of Gondwanan origin for intercontinental disjunction in the southern hemisphere does not find corroboration from fossils (see Amorim and Silva, 2002). The conflict between biogeographical patterns and molecular data in different groups of animals and plants led to a naïve neodispersalism, with transoceanic dispersal proposed again to explain intercontinental disjunctions.

Alternative solutions have been advanced more recently to explain intercontinental disjunction of groups with tropical and with temperate distributions. Temperate groups disjunct between southern South America and Australia can be explained as the result of vicariance during the middle of the Cenozoic (Amorim et al., 2009)—neither Gondwanan origin nor transoceanic dispersal—when physical connection between Australia, Antarctica, and South America was finally broken. This was later corroborated by inferences with molecular data of colletid bees (Almeida et al., 2011) and of scio-nine tabanids (Lessard et al., 2013).

In other words, the fact that a group is not old enough to be Gondwanan does not mean that its disjunction is necessarily explained by transoceanic dispersal. Amorim et al. (2018), on the other hand, proposed a solution for transtropical distribution patterns assuming an association of vicariance and extinction at the second half of the Cenozoic. Many or most cases of transtropical patterns actually correspond to a pseudocongruence with true Gondwanan patterns. There is plenty of documention of a large tropical biota in the northern hemisphere during the late Cretaceous and first half of the Cenozoic in different groups of plants and animals—with secondary expansion from North America into South America, from Europe into Africa, and from Asia into northern Australia (see discussion in Amorim et al., 2018). The Eocene-Oligocene global cooling led to the extinction of huge portions of this Laurasian tropical fauna and flora mostly in North America and Europe. The connection, hence, between the rich and diversified Oriental tropical biota with tropical elements in Africa and South America is, hence, a false congruence with true Gondwanan patterns. This is seen in groups of flies—as in the manotine genus Eumanota, a clade basically with Oriental distribution and a species in the high Andean areas in Colombia (Amorim et al., 2018)—but it is also known from many other groups of insects, plants, and vertebrates.

In this context, true Laurasian and true Gondwana patterns are not very easy to find. A rare clear case was recently published for the bombyliid subfamily Bombyliinae (Diptera: Bombyliidae) (Li and Yeates, 2019). The bombylid fossil record and the age of the group inferred from molecular data make it possible to recognize a “Gondwanan backbone” with disjunction between Australia, Africa, and South America, and expansion toward Laurasian terranes (Li and Yeates, 2019).

The interpretation in this study of biogeographical patterns of the Leiinae can be made with the support of fossils associated to a formal phylogenetic reconstruction with ample taxonomic sampling in the subfamily (fig. 107). The discussion above shows that most mycetophilid fossil species described by Blagoderov and Grimaldi (2004) belong in the Tetragoneurinae. Among the fossils that actually fit in the Leiinae, Lecadonileia may be a Cycloneurini, whereas the Lower Cretaceous Myanmar amber genus Temaleia clearly fits in a clade nested within the Leiinae, as sister to the extant genera of the Leiini. Temaleia birmitica comes out as Cenomanian—92–98 Ma—providing a minimum age for the Leiini.

Additionally, the association of Alavamanota—with Aptian–middle Albian (120–110 Ma) fossils in Spain and Cenomanian (99 Ma) fossils in Myanmar—with the Manotini, possibly as sister of the Recent genus Manota, sets the entire backbone of the subfamily in the Lower Cretaceous. This set of evidence suggests that the origin and initial diversification of the crown mycetophilids may have occurred in the late Jurassic or earliest Cretaceous. There are fossils of the subfamilies Sciophilinae, Gnoristinae, and Tetragoneurinae already known from the Valanginian to the very early Aptian, between 134 and 125 Ma (fig. 107).

Highly relevant to this discussion is that a Lower Cretaceous age for the Leiinae backbone is perfectly consistent with the geological age of separation of New Zealand from the rest of the southern Gondwana, assumed to have occurred at about 80 Ma (see clades of New Zealand distribution marked with NZ in fig. 107). The presence of –a large number of endemic elements of Leiinae in New Zealand and in other southern temperate areas do not demand any ad hoc hypotheses of dispersal. In other words, the age of the Manotini and the Leiini fossils and the age of the geological separation of New Zealand from the rest of southern Gondwana clearly sets southern temperate Gondwanan terranes as the original area of distribution of the nodes connecting the tribes of Leiinae (fig. 107).

It would not be a coincidence, then, that Cretaceous fossils of the Manotini and Leiini are known from deposits in the northern hemisphere, while other main leiine clades are still unknown from the Cretaceous fossil record. The Manotini and the Leiini are two of the seven groups of the subfamily that are hypothesized here to have expanded out of southern Gondwana terranes (blue numbered arrows in fig. 107). The recent discovery of Triassic to Paleogene amber in Australia (Stilwell et al., 2020) may bring exceptional light on our understanding of large parts of the history of the Leiinae and thereby allow us to test the hypotheses raised here.

This general interpretation of the leiine biogeographical evolution provides support for understanding the endemic southern temperate distribution of several small extant clades of the subfamily as corresponding to an original distribution in Gondwana; these clades include: (1) Paraleia, in temperate Australia and South America; (2) certain genera with uncertain position within the Leiinae, as Thoracothropis, Trichoterga, and Paracycloneura; (3) the entire Cycloneurini clade (except for Procycloneura, which expanded into more northern areas in South America); (4) the temperate species of Leiella in the Neotropical region; and (5) the Anomalomyiini in New Zealand and Australia. Their presence in southern areas do not represent a secondary occupation of these regions, but rather these taxa are original members of the southern Gondwanan biota.

Correspondingly, the presence of Leiinae groups in more northern areas of the globe, frequently in the northern hemisphere, can be understood as cases of independent secondary expansion of these clades from their southern Gondwana distribution to the north. Tectonic movements of Gondwanan terranes that are now separate continents began in the early Jurassic, about 182 Mya, but south to north seafloor spreading in the Atlantic began only about 135–130 Mya, in the earliest Cretaceous. Low-latitude connections between these continents remained until 119–105 million years ago. Latitudinal zonation of faunas and floras in Gondwana seems an inevitable scenario, but the first stages of the separation between Africa and the rest of the Gondwana in the south apparently may have been too early to affect the basal leiine clades.

The distribution of nonsouthern temperate clades in the Leiinae must be understood as biotic expansion (fig. 107). This includes: (1) Garretella, in the Selkirkiini, into the Nearctics; (2) the Megophthalmidiini, into tropical Neotropical areas as well as into the Afrotropical, Oriental, Nearctic, and Palaearctic regions; (3) the Rondaniellini, with the Oriental-Holarctic distribution of Rondaniella, and the Oriental and Australasian distribution of Indoleia; (4) the Afrotropical species of Paradoxa; (5) the Manotini except Leiella, including one species known from Baltic amber; (6) a subclade of Anomalomyia in Africa; and (7) the Leiini, worldwide in distribution, mostly in tropical areas (with the exception of the New Caledonian genus Caledonileia). The cases of Acrodicrania and Paradoxa are less clear. More robust explanations for their distribution depends on molecular inferences for the age of divergence within each of these genera. Species of Procycloneura and of Leiella in tropical areas in South and Central America also represent shifts in smaller scales.

It is worth remembering that the Lower Cretaceous flora was extensively composed of gymnosperm forests (including fungi associated to these forests). The diversification of the Mycetophilidae beginning in the Lower Cretaceous, to reach the extant diversity of the family, is connected to this turnover of gymnosperm to angiosperm forest and the correspondent shift in associated fungi. The turnover happened mostly during the second half of the Cretaceous, angiosperms becoming dominat in forests in tropical areas or mixed temperate forests on both hemispheres.

The mycophagy of most mycetophilid larvae, therefore, implies that the evolution of the family is largely affected by the evolution of the fungi and the forest turnover. The southern hemisphere conifer components in extant forests includes primarily Araucaria Jussieu and Agathis Salisbury and Podocarpaceae, restricted to temperate South America, New Zealand, New Caledonia, and/or Australia. These conifer elements were probably in large scale the original forest components in the leiine southern Gondwanan distribution. A molecular phylogeny of the Mycetophilidae with wide generic and geographic sampling, associated to information on Mesozoic fossils and to the evolution of the fungi will provide a very special understanding of evolution of the family.

At least some of the extant mycetophilid clades (e.g., certain genera of sciophilines and gnoristines) have temperate distribution in the northern hemisphere. The presence of these clades in tropical areas may also be secondary, following the diversification of angiosperm forests in tropical areas in the late Cretaceous.

Finally, no Lebanon amber mycetophilid fossils are known yet. Blagoderov and Grimaldi (2004: 5) note that Lebanon amber includes a great range of ages, from the uppermost Jurassic (152 Ma) to the Albian (112 Ma), and that sciaroids in Lebanese amber are the oldest known amber fossils of the superfamily. Mycetophilid fossils from Lebanon and Australia deposits would fill an important gap and would be extremely helpful in understanding the early stages of the evolution of the family.