APPENDIX 1.

Taxa examined in wing venation variability analysis. † denotes an extinct taxon.

Taxon Reference/Depository
Asiodixa pura Papp et al., 2006
Asiodixa maculosa Papp et al., 2006
Dixa aliciae WRBU
Dixa babai Takahashi, 1958
Dixa brevis WRBU
Dixa californica WRBU
Dixa camerounensis WRBU
Dixa cimbrica† Ansorge, 1992
Dixa clavata WRBU
Dixa dilatata WRBU
Dixa dyari WRBU
Dixa fluvica WRBU
Dixa fusca WRBU
Dixa hegemonica WRBU
Dixa hikosana Takahashi, 1958
Dixa hoffmani WRBU
Dixa inextricata WRBU
Dixa johannseni WRBU
Dixa kaplani Wagner et al., 1991/1992
Dixa kyushuensis Takahashi, 1958
Dixa lobata WRBU
Dixa lobatus WRBU
Dixa longistyla Takahashi, 1958
Dixa lunata WRBU
Dixa maculata WRBU
Dixa melanderi WRBU
Dixa minuta† Hennig, 1966
Dixa minutiformis Takahashi, 1958
Dixa modesta Johannsen, 1923
Dixa modesto WRBU
Dixa naevia WRBU
Dixa nebulosa WRBU
Dixa neoaliciae WRBU
Dixa neohegemonica WRBU
Dixa nipponica Takahashi, 1958
Dixa notata WRBU
Dixa nova Peters, 1981
Dixa nubilipennis WRBU
Dixa obtusa Takahashi, 1958
Dixa orientale WRBU
Dixa priscula† Cockerell, 1921
Dixa puberula Disney, 1975
Dixa punctata Wagner et al., 1991/1992
Dixa rathyme WRBU
Dixa serrata WRBU
Dixa serrifera WRBU
Dixa similis WRBU
Dixa spiralis WRBU
Dixa stuckenbergi WRBU
Dixa submaculata WRBU
Dixa subobscura Takahashi, 1958
Dixa terna WRBU
Dixa tertiaria† Theobald, 1937
Dixa trilineata Takahashi, 1958
Dixa xavia WRBU
Dixa yamatona Takahashi, 1958
Dixella aegyptiaca Wagner et al., 1991/1992
Dixella aestivalis WRBU
Dixella amphibia Disney, 1975
Dixella attica Wagner et al., 1991/1992
Dixella aurora WRBU
Dixella autumnalis WRBU
Dixella corensis Peters, 1992
Dixella cornuta WRBU
Dixella curvistyla† This study
Dixella deltoura WRBU
Dixella distans† Hennig, 1966
Dixella eomarginata† This study
Dixella fernandezae Chaverri and Borkent, 2007
Dixella filicornis Disney, 1975
Dixella filiforceps† Hennig, 1966
Dixella fraxina Taber, 2010
Dixella fuscifrons Wagner et al., 1991/1992
Dixella fuscinervis WRBU
Dixella golanensis Wagner et al., 1991/1992
Dixella hansoni Chaverri and Borkent, 2007
Dixella hernandezi Chaverri and Borkent, 2007
Dixella indiana Peters and Cook, 1966
Dixella intacta† This study
Dixella israelis Wagner et al., 1991/1992
Dixella jironi Chaverri and Borkent, 2007
Dixella laeta Peus, 1936
Dixella limai WRBU
Dixella lobata Chaverri and Borkent, 2007
Dixella maculata Chaverri and Borkent, 2007
Dixella martini WRBU
Dixella neozelandica Belkin, 1968
Dixella nixiae Peters, 1980
Dixella obscura WRBU
Dixella pollex Nowell, 1980
Dixella pyrenaica Peus, 1936
Dixella scitula Belkin et al., 1970
Dixella serotina Disney, 1975
Dixella shannoni Chaverri and Borkent, 2007
Dixella solomonis WRBU
Dixella spinilobata† This study
Dixella succinea† Hennig, 1966
Dixella suzukii Chaverri and Borkent, 2007
Dixella techana WRBU
Dixella torrential WRBU
Dixella trinitensis WRBU
Dixella venezulensis Chaverri and Borkent, 2007
Dixella vespertina WRBU
Dixella woodi Chaverri and Borkent, 2007
Eucorethrina convexa† Lukashevich, 1996
Eucorethrina flexa† Kalugina, 1985, Lukashevich, 1996
Eucorethrina westwoodi† Lukashevich et al., 2001
Meringodixa chalonensis Nowell, 1951
Mesodixa biambulacra Belkin et al., 1970
Neodixa minuta Belkin, 1962
Nothodixa campbelli Belkin, 1968
Nothodixa otagensis Belkin, 1962
Nothodixa septentrionalis Belkin, 1962
Nothodixa philpotti Belkin, 1962
Syndixa mollis† Lukashevich, 1996
Syndixa sibirica† Lukashevich, 1996

APPENDIX 2.

Character states used in the analysis of fossil and extant dixid wing venation.

1. Vein Sc apex relative to the origin of Rs: basal [>2X vein width] (0); subbasal [<2X vein width] (1); even (2); subapical [<2X vein width] (3); apical [>2X vein width] (4).

2. Crossvein r-m origin relative to the bifurcation of Rs: basal (0); subbasal [<2X vein width] (1); even (2); subapical [<2X vein width] (3); apical (4).

3. Crossvein m-cu origin relative to the terminus of r-m: basal (0); subbasal [<2X vein width] (1); even (2); subapical [<2X vein width] (3); apical (4).

4. Vein A1 terminus relative to the origin of Rs: basal (0); subbasal [<2X vein width] (1); even (2); subapical [<2X vein width] (3); apical (4).

5. Vein A1 terminus relative to Sc terminus: basal (0); subasal [<2X vein width] (1); even with (2); subapical [<2X vein width] (3); apical (4).

6. Vein A1 terminus relative to the bifurcation of Cu: basal (0); subbasal [<2X vein width] (1); even (2); subapical [<2X vein width] (3); apical (4).

7. Vein R2+3: branched (0); unbranched (1).

8. R2+3 curvature: straight or very slightly arched (0); strongly arched (1).

9. Vein R2+3 branch relative to the bifurcation of M: basal (0); subbasal [<2X vein width] basal (1); even (2); subapical [<2X vein width] (3); apical (4).

10. Vein R1: fused to C far basal (near 3/4 wing length) of wing apex (0); closer to C than R2 and fused near wing apex (1); equidistant to C and R2 and fused near wing apex (2).

11. Vein R2: not fused with R1 (0); fused with R1 (1).

12. Rs: straight (0); sigmoidal (1).

13. Wing length/width: <2.5(0); 2.5 - 3 (1); >3 <4 (2) >4 (3).

APPENDIX 3.

Morphological data matrix (Dixidae wing and venation characters only).

Taxon 1 2 3 4 5 6 7 8 9 10 11 12

13

Dixa aliciae 2 1 2 2 2 0 0 1 4 1 0 0 -
Dixa babai 0 - 4 4 4 0 0 1 0 1 0 0 1
Dixa brevis 2 4 4 4 4 0 0 1 0 1 0 0 0
Dixa californica 3 2 4 4 4 0 0 1 2 1 0 0 -
Dixa camerounensis 0 4 4 2 4 0 0 1 0 1 0 0 -
Dixa clavata 2 3 4 4 4 0 0 1 0 1 0 0 -
Dixa dilatata 0 3 4 4 4 0 0 1 3 1 0 0 -
Dixa dyari 0 2 4 4 4 0 0 1 4 1 0 0 -
Dixa fluvica 1 2 4 4 4 0 0 1 0 1 0 0 -
Dixa fusca 0 3 4 4 4 0 0 1 0 1 0 0 -
Dixa hegemonica 1 3 4 4 4 0 0 1 2 1 0 0 -
Dixa hikosana 0 - 4 4 4 0 0 1 0 1 0 0  1
Dixa hoffmani 0 2 0 4 4 0 0 1 4 1 0 0 -
Dixa inextricata 2 2 4 4 4 0 0 1 0 1 0 0 -
Dixa johannseni 4 2 4 4 4 0 0 1 0 1 0 0 -
Dixa kaplani 0 2 0 2 4 0 0 1 3 1 0 0 1
Dixa kyushuensis 0 2 4 4 4 0 0 1 4 1 0 0 1
Dixa lobata 4 2 4 4 4 2 0 1 0 1 0 0 -
Dixa lobatus 2 4 4 4 4 0 0 1 0 1 0 0 -
Dixa longistyla 0 0 4 0 4 0 0 1 4 1 0 0 1
Dixa lunata 0 4 4 4 4 0 0 1 4 1 0 0 -
Dixa maculata 0 4 4 4 4 0 0 1 4 1 0 0 -
Dixa melanderi 2 4 4 4 4 0 0 1 4 1 0 0 -
Dixa minutiformis 0 3 4 4 4 2 0 1 0 1 0 0 1
Dixa modesta 0 4 4 2 4 0 0 1 0 1 0 0 2
Dixa modesto 0 4 4 4 3 0 0 1 4 1 0 0 -
Dixa naevia 2 2 4 4 4 0 0 1 4 1 0 0 -
Dixa nebulosi 0 2 4 4 4 0 0 1 2 1 0 0 -
Dixa neoaliciae 0 0 0 4 4 1 0 1 4 1 0 0 -
Dixa neohegemonica 0 4 4 4 4 0 0 1 2 1 0 0 -
Dixa nipponica 0 - 4 4 0 0 0 1 4 1 0 0 1
Dixa notata 0 4 4 4 4 0 0 1 0 1 0 0 -
Dixa nubilipennis 0 4 4 2 4 0 0 1 0 1 0 0 -
Dixa obtusa 0 - 4 4 4 0 0 1 0 1 0 0 1
Dixa orientale 4 3 4 4 4 0 0 1 4 1 0 0 -
Dixa puberula 1 3 4 4 4 1 0 1 2 1 0 0 1
Dixa punctata 0 2 0 2 4 0 0 1 2 1 0 0 2
Dixa rhathyme 2 3 4 4 4 1 0 1 1 1 0 0 -
Dixa serrata 0 2 4 4 4 0 0 1 0 1 0 0 -
Dixa serrifera 0 4 4 3 4 0 0 1 3 1 0 0 -
Dixa similis 0 4 4 4 4 0 0 1 2 1 0 0 -
Dixa spiralis 0 0 4 2 4 0 0 1 0 1 0 0 -
Dixa stuckenbergi 0 0 4 1 4 0 0 1 4 1 0 0 -
Dixa submaculata 1 3 4 4 4 0 0 1 4 1 0 0 -
Dixa subobscura 0 0 4 4 4 0 0 1 0 1 0 0 1
Dixa terna 0 3 4 4 4 0 0 1 0 1 0 0 -
Dixa trilineata 0 - 4 4 4 2 0 1 4 1 0 0 1
Dixa xavia 0 4 4 4 4 0 0 1 4 1 0 0 -
Dixa yamatona 0 - 4 4 4 1 0 1 2 1 0 0 1
Dixa priscula 0 2 0 4 4 0 0 1 0 1 0 0 2
Dixa cimbrica 1 4 0 4 4 2 0 1 4 1 0 0 0
Dixa minuta 0 0 2 - - - 0 1 4 1 0 0 1
Dixa tertiaria 0 0 1 3 4 1 0 1 4 1 0 0 2
Dixella aegyptiaca 0 1 4 4 4 0 0 1 2 1 0 0 2
Dixella aestivalis 0 0 4 4 4 0 0 1 0 1 0 0 -
Dixella amphibia 2 4 4 4 4 0 0 1 1 1 0 0 1
Dixella attica 3 2 4 4 4 0 0 1 4 1 0 0 0
Dixella aurora 0 4 3 4 4 0 0 1 0 1 0 0 -
Dixella autumnalis 0 2 4 4 4 0 0 1 0 1 0 0 -
Dixella corensis 0 2 4 4 4 0 0 1 1 1 0 0 -
Dixella cornuta 1 2 4 4 4 0 0 1 0 1 0 0
Dixella deltoura 0 2 - 4 4 0 0 1 0 1 0 0 -
Dixella fernandezae 0 0 3 4 4 0 0 1 0 1 0 0 1
Dixella filicornis 0 0 4 4 4 2 0 1 1 1 0 0 0
Dixella fraxina 0 3 4 4 4 0 0 1 0 1 0 0 1
Dixella fuscifrons 0 4 4 4 4 0 0 1 0 1 0 0
Dixella fuscinervis 4 4 4 4 4 0 0 1 0 1 0 0 -
Dixella golanensis 2 4 4 4 4 2 0 1 4 1 0 0 1
Dixella hansoni 0 0 2 4 4 0 0 1 1 1 0 0 1
Dixella hernandezi 4 4 2 4 3 0 0 1 1 1 0 0 1
Dixella indiana 0 4 4 4 4 0 0 1 0 1 0 0 2
Dixella israelis 0 4 4 4 4 4 0 1 0 1 0 0 2
Dixella jironi 0 2 2 4 4 0 0 1 0 1 0 0 1
Dixella laeta 4 0 4 4 4 0 0 1 2 1 0 0 -
Dixella limai 0 2 0 4 4 0 0 1 0 1 0 0 -
Dixella lobata 0 2 2 4 4 0 0 1 - 1 0 0 1
Dixella maculata 4 2 4 2 0 0 0 1 2 1 0 0 1
Dixella martini 0 4 4 4 4 0 0 1 4 1 0 0 -
Dixella neozelandica 1 4 4 4 4 0 0 1 0 1 0 0 2
Dixella nixiae 0 2 1 4 4 0 0 1 4 1 0 0 1
Dixa nova 4 3 4 4 4 0 0 1 4 1 0 0 2
Dixella obscura 0 4 4 4 4 0 0 1 0 1 0 0 -
Dixella pollex 0 4 4 0 4 0 0 1 2 1 0 0 1
Dixella pyrenaica 0 0 4 4 4 2 0 1 4 1 0 0 -
Dixella scitula 2 4 0 4 4 0 0 1 0 1 0 0 2
Dixella serotina 0 3 4 4 4 1 0 1 0 1 0 0 1
Dixella shannoni 4 0 2 4 0 0 0 1 0 1 0 0 1
Dixella solomonis 2 0 4 4 4 0 0 1 2 1 0 0 -
Dixella suzukii 0 2 0 4 4 0 0 1 2 1 0 0 1
Dixella techana 0 4 0 4 4 0 0 1 3 1 0 0 -
Dixella torrentia 0 2 0 4 4 4 0 1 0 1 0 0 -
Dixella trinitensis 0 0 4 0 4 0 0 1 4 1 0 0 -
Dixella venezulensis 0 0 4 4 4 0 0 1 0 1 0 0 1
Dixella vespertina 1 3 2 4 4 0 0 1 0 1 0 0 -
Dixella woodi 2 0 4 4 4 0 0 1 0 1 0 0 1
Dixella spinilobata 0 - - - - - 0 1 - 1 0 0 2
Dixella eomarginata 2 3 2 4 4 0 0 1 1 1 0 0  1
Dixella curvistyla 0 0 3 - - - 0 1 0 1 0 0 0
Dixella intacta 2 3 2 0 0 0 0 1 0 1 0 0
Dixella distans 0 3 4 4 4 4 0 1 4 1 0 0 -
Dixella filiforceps 0 2 3 4 4 2 0 1 4 1 0 0 -
Dixella succinea 0 2 4 4 4 1 0 1 4 1 0 0 1
Mesodixa biambulacra 1 2 3 4 4 0 0 1 2 1 0 0 1
Meringodixa chalonensis 2 4 4 4 4 1 0 1 2 1 0 0 1
Neodixa minuta 0 0 4 4 4 0 1 1 0 1 0 0 1
Asiodixa pura 0 0 3 2 4 0 0 1 0 1 0 1 0
Asiodixa maculosa 0 0 4 0 4 0 0 1 0 1 0 1 1
Nothodixa campbelli 0 0 4 4 4 0 0 1 4 1 0 0 0
Nothodixa otagensis 0 0 4 4 4 2 0 1 4 1 0 0 1
Nothodixa septentrionalis 0 0 4 4 4 0 0 1 1 1 0 0 0
Nothodixa philpotti 0 0 4 0 4 0 0 1 4 1 0 0 0
Eucorethrina convexa 4 4 2 4 3 0 0 0 0 2 0 0 0
Eucorethrina flexa 3 4 2 1 0 0 0 0 0 2 0 0 1
Eucorethrina westwoodi 4 4 2 4 2 0 0 0 0 2 0 0 0
Syndixa mollis 4 4 2 4 3 4 0 0 0 - 1 0 0
Syndixa sibirica 4 4 2 4 1 4 0 0 0 - 1 0 1