Table S1. List of important synapomorphies for the nodes. Female characters (0–161); Male characters (162–238). § = plesiomorphic state difficult to assess because several options are possible or when the character was not applicable for some taxa.
Megachilini
Characters / Synapomorphic State / Plesiomorphic State / Comments2 / Antennal socket with a distinct mesal projection on upper half / Mesal projection absent
30 / Preoccipital carina present / Absent / Reversal in M. angelarum; Parallelism in D. cincta
34 / Outer margin of pronotal lobe carinate or lamellate / Distinctly rounded, not carinate / 3 reversals: M. discolor, M. pugnata and C. (Coelioxys s. str.); parallelism in D. cincta
75 / Outer surfaces of fore and mid tibiae apically with acute angle and distinct notch anteriorly / Notch absent
132 / Apodeme of S6 with distinct disc between marginal ridge and transapodemal ridge / With disc reduced or absent / Reversal in M. rotundata + (M. angelarum + (N. chapini + N. cf. clypeata)); Parallelism in A. utahense
145 / H7: apodemal region angulate to rest of H7 / Apodemal region not angulate to rest of H7 / 3 reversals within Coelioxys: C. (Torridapis), C. rotundicauda and C. argentea
151 / H7 with strong protrusion on the lamina spicularis, near base of lateral process present, distinct / Protrusion absent / 4 reversals within Coelioxys: C. (Torridapis), C. scioensis, C. argentea and C. (Xerocoelioxys) except C. serricaudata
190 / T6 dorsal processes: apex with two dorsal process / T6 dorsal processes absent / 3 reversals (Radoszkowskiana, Noteriades and M. fulva)
224 / S7 divided into two small sclerites / S7 undivided / 1 reversal within Coelioxys: C. (Synocoelioxys); parallelism in A. utahense
Coelioxys + Radoszkowskiana
Characters / Synapomorphic State / Plesiomorphic State / Comments19 / Mandible up to three teeth / With more than three teeth / 3 parallelisms: L. apicalis, D. cincta and O. fasciata
23 / Mandible with outer premarginal impressed fimbria reduced or absent / Outer premarginal fimbria present / 6 parallelisms: L. apicalis, D. cincta, A. utahense, A. volkmanni, O. fasciata and O. californica
26 / Paraocular area conspicuously covered with appressed hairs at least on lower margin where integument not visible beneath hairs / Covered predominantly with subappressed or erect hairs, underlying integument visible / 3 reversals: C. (Synocoelioxys), C. dinellii and C. (Dasycoelioxys) + remaining subgenera; 2 parallelisms: O. fasciata and N. chapini + N. cf. clypeata
34 / Carina of pronotal tubercle conspicuously elevated, lamellate, forming a distinct lamella / Sharply carinate but not forming lamella, discrete, normally hidden by long hairs / 4 reversals: C. ducalis + C. weinlandi, C. scioensis, C. dinellii, C. (Dasycoelioxys) + remaining subgenera
55 / Mesoscutellum with subappressed or appressed hairs posteriorly / Without subappressed or appressed hairs / 5 reversals: C. reginae, C. alatiformis, C. (Leuraspidia), C. mexicana and C. (Dasycoelioxys) + remaining subgenera
61 / Axilla well defined, margin between axilla and rest of mesoscutellum concave to angulate / Poorly defined, posterior margin of mesoscutellum evenly convex / 2 parallelisms: D. cincta and O. fasciata
97 / T1 laterally conspicuously covered with appressed hairs and forming at least narrow bands from the base towards the apex / Bands composed of subappressed or suberect hairs at least basally / 5 reversals: C. ducalis + C. weinlandi, C. kuscheli, C. dolichos, Coelioxys s. str. and C. (Rozeniana) + C. (Paracoelioxys) (except C. funeraria) + C. (Boreocoelioxys))
112 / Metasoma shape conical, tapering towards apex / Metasoma ovoid, cylindrical
113 / Metasomal sternal scopa absent / Present / Parallelism in D. cincta
164 / Gena: pilosity composed of appressed hairs / Composed of suberect or erect hairs / 4 reversals: C. (Synocoelioxys), C. dinellii, C. chilensis, C. (Dasycoelioxys) and remaining subgenera except C. grindeliae
Radoszkowskiana
Characters / Synapomorphic State / Plesiomorphic State / Comments119 / T6 apex emarginate / Not emarginate
134 / S6 apical margin emarginate / Not emarginate / 3 parallelisms: M. pugnata, M. rotundata and C. afra
170 / Fore coxa lacking spine-like process / § / Parallelism in N. cf. clypeata
180 / Sterna (at least S2-S3) conspicuously covered with plumose or scale-like hairs medially / Disc nearly bare, not covered with scale-like or plumose hairs, or covered with long, erect hairs / 3 parallelisms: M. felina, M. discolor and M. angelarum
190 / T6 dorsal processes: apex forming a transverse irregular crenulate plate / T6 dorsal processes: apex with two dorsal process / Parallelism in M. fulva
205 / S5 integument membranous / § / Parallelism in M. pugnata + M. rotundata + M. angelarum + Noteriades
211 / Gradulus of S5 evanescent / Gradulus strong / Parallelism in (M. pugnata + (M. rotundata + (M. angelarum + (Noteriades))))
231 / Gonocoxal apex (concavity): present, strongly concave / Concavity absent
238 / Penis valve abruptly tapering subapically / Gradually tapering towards the apex or nearly straight / Parallelism in M. angelarum
R. gusevi + R. tkalcui
Characters / Synapomorphic State / Plesiomorphic State / Comments81 / Hind coxa with ventral carina / Ventral carina absent
193 / T6 laterobasal teeth very short, flat, almost vestigial / T6 basolateral teeth absent / 2 parallelisms: M. rotundata and M. angelarum
209 / Apical rim of S5 emarginate, width less than 2x longer than depth / Apical rim weakly emarginate, width more than 3x longer than depth
225 / S8 apex emarginate / Apex produced medially
227 / S8 base triangular, base wide and tapering to acute apex / Base convex or trapezoidal, base wide and tapering, rounded or trapezoidal apex
Coelioxys
Characters / Synapomorphic State / Plesiomorphic State / Comments3 / Compound eye hairy / Compound eye bare / 1 reversal: C. (Liothyrapis) + C. (Torridapis)
32 / Omaulus angulate, carinate or lamellate / Rounded / 2 parallelisms: D. cincta and Noteriades
56 / Dorsal and superior surfaces of mesoscutellum: 0 - fully separated by a distinct subcarinate, somewhat sharp, nearly impunctate edge, forming a distinct acute angle; 1 - surfaces separated by an indistinct subcarinate edge, forming an obtuse angle, the edge is at least sparsely punctate / Surfaces not separated, continuously curving in profile / Reversal in (C. (Coelioxys s. str.) + C. (Xerocoelioxys)) + (remaining subgenera)); Parallelism in Noteriades
62 / Axilla (free apical portion): acutely separated from posterior margin of rest of mesoscutellum. / Without free portion, axilla weakly differentiated from rest of mesoscutellum / Parallelism in D. cincta
111 / T3 gradulus interrupted medially / Gradulus indistinct / 6 reversals: C. ducalis + C. weinlandi, C. scioensis, C. (Allocoelioxys) except C. echinata, C. mexicana, C. (Boreocoelioxys) and C. (Coelioxys s. str.) + C. (Xerocoelioxys)
116 / T6 gradually tapering towards apex / T6 rounded / 2 reversals: C. caudata + (C. acanthura + C. argentea) and C. chichimeca
125 / T6 dorsal carina present / Absent / 3 reversals: C. ducalis, C. alternata + C. hunteri and C. acanthura
136 / S6 gradually tapering towards apex / S6 rounded, not tapering / 8 reversals: C. (Liothyrapis), C. afra, C. caudata, C. froggatti, C. gonaspis + C. modesta, C. chichimeca, C. (Coelioxys s. str. and C. edita + (C. bisoncornua + C. aperta)
204 / S5 long, ≥1.25x longer than wide wide / S5 wide, ≥2× wider than long
205 / S5 integument strongly sclerotized as the precedent sterna / § / 3 parallelisms: L. apicalis, D. cincta + (A. utahense + (O. fasciata + A. volkmanni)) and M. discolor
217 / Outer margins of S6 heavily sclerotized, contrasting with the medial area / Heavily or lightly sclerotized or translucent, not contrasting with the medial area / 2 reversals: C. torrida and C. (Allocoelioxys) except C. afra and C. argentea; Parallelism in M. fulva
223 / S6 basal membranous lip folded ventrad / Not folded ventrad / 2 parallelisms: M. felina and M. fulva
C. (Torridapis) + C. (Liothyrapis)
Characters / Synapomorphic State / Plesiomorphic State / Comments9 / Supraclypeal area elevated medially, forming a sharp keel at least apically / Not elevated or keeled
181 / Apical rim of S4 emarginate / Apical rim entire / 5 parallelisms: C. odin, C. erythrura, C. afra, C. alatiformis and C. quadridentata
210 / Postgradular area of S5 densely, conspicuously covered with plumose hairs / Inconspicuously hairy or not densely hairy / Parallelism in C. caudata + (C. acanthura + C. argentea)
C. (Torridapis)
Characters / Synapomorphic State / Plesiomorphic State / Comments7 / Midocellar area sculpturing (anterior to and immediately surrounding mid ocellus) impunctate around mid ocellus and densely punctate elsewhere / Punctate or densely punctate throughout / 3 parallelisms: C. albolineata, C. alatiformis and C. vigilans
8 / Area around mid ocellus swollen around the entire circumference with a carinate edge. / Flat, not swollen or carinate / Parallelism in C. scioensis
42 / Mesoscutum medioposteriorly (0 - strongly carinate, carina extending from the apex to the medial area; 1 - weakly carinate, a rounded elevated area restricted to the subapical area) / Not carinate
54 / Mesoscutellum: medial surface keeled / § / Parallelism in C. (Glyptocoelioxys) except both C. praetextata and C. germana
55 / Mesoscutellum: length of dorsal raised portion: 0 - obsolescent, inconspicuous and detectable only basally; 1 - strong, sharp but only basally / § / Parallelism in C. odin
59 / Metanotum basally conspicuously expanded, flat / Not produced or expanded / Reversal in C. torrida
101 / T1 lateral bands absent / Present / Reversal in C. torrida; Parallelism in C. kuscheli
117 / T6 apex ending in a short, rounded tooth or ending in a slightly elevated tip / Never ending in a spine-like projection / Parallelism in C. (Cyrtocoelioxys) except C. gonaspis
120 / T6 apex subacute or acute, greatly elongate / § / 3 parallelisms: C. nasuta, C. caudata + (C. argentea + C. acanthura) and C. chichimeca
142 / S6 greatly elongate, subacute or acute apically / § / 2 parallelisms: C. nasuta and C. acanthura + C. argentea
150 / Lateral process of H7 long / Short or absent / 4 parallelisms: C. rotundicauda, C. nasuta, C. argentea and C. chichimeca
149 / Apodemal region of H7 narrow, subacute wider, rounded or quadrate / Apodemal region of H7 wider, rounded or quadrate / Reversal in C. scioensis; Parallelism in C. (Allocoelioxys)
156 / H8 (posterior expansion): narrow, acutely pointed at apex / Posteriorly expanded not produced / Parallelism in C. odin
182 / S4 medially sulcate and hairy / Flat / 3 parallelisms: C. nasuta, C. costaricensis and C. praetextata + (C. cerasiopleura + (C. chilensis + C. cayennensis))
192 / Dorsal processes of T6 (orientation): slanting / Straight / 2 parallelisms: C. odin and C. (Coelioxys s. str.) + C. (Xerocoelioxys) + remaining subgenera except C. alata
193 / T6 laterobasal teeth very short, flat, almost vestigial / § / Reversal in C. torrida
214 / Gradulus and basal margin of S5 meeting medially / Not meeting medially / 2 parallelisms: C. apicata + C. decipiens and C. (Glyptocoelioxys) except C. cayennensis, C. mexicana and C. germana
230 / Gonocoxa subapically strongly compressed laterally / §
C. (Liothyrapis)
Characters / Synapomorphic State / Plesiomorphic State / Comments63 / Axilla: length of free apical portion: short, not produced beyond or up to the posterior margin of mesoscutellum. Not applicable for state 0 in previous character / Long, free apical portion produced at least to the posterior margin of mesoscutellum / 6 parallelisms: C. alternata, C. slossoni, C. sodalis, C. serricaudata, C. aperta and C. (Paracoelioxys)
77 / Fore and middle tibiae: medial and anterior spines parallel to each other and of similar orientation and length / Divergent from one another and the medial one much longer than the anterior / Reversal in C. scioensis; Parallelism in C. chichimeca + (C. paraguaya + C. speculifera)
85 / Hind tibia medial spine forked / Not forked / Reversal in C. scioensis
115 / T6 angulate near midlength / Not angulate / Reversal in C. scioensis; 3 parallelisms: C. dolichos, C. mesae and C. rufitarsis
117 / T6 apex ending in a long spine-like projection / Never ending in a spine-like projection / Parallelism in C. gonaspis
118 / T6 subapically with long, thick, erect hairs / Without long, thick, erect hairs / 3 parallelisms: C. (Synocoelioxys), C. (Cyrtocoelioxys) and C. aperta
120 / T6 apex spinose / § / Parallelism in C. gonaspis
121 / T6 lateral carinae present, very expanded with regular margins / § / Reversal in C. scioensis, 4 parallelisms: C. (Synocoelioxys), C. dolichos and C. tolteca, C. (Xerocoelioxys) except C. aperta + C. bisoncornua and C. rufitarsis
129 / T6 dorsal carina laterally at least inconspicuously hairy / Bare / 2 parallelisms: C. (Cyrtocoelioxys) and C. (Dasycoelioxys)
136 / S6 lateral margins subapically abruptly tapering / § / 6 parallelisms: C. caudata, C. froggatti, C. gonaspis + C. modesta, C. chichimeca, C. (Coelioxys s. str.) and C. edita (C. aperta + C. bisoncornua)
139 / S6 marginal pilosity forming a conspicuous fringe of dense, short hairs / § / Parallelism in C. gonaspis + C. modesta
141 / S6 dorsolateral margin with a conspicuous, long hook / With a short hook / Reversal in C. scioensis; 2 parallelisms: C. ducalis and C. (Synocoelioxys) + C. (Allocoelioxys)
161 / Gonostylus apically thickened / Not thickened / Parallelism in Megachile + Noteriades except with reversals in M. rotundata and M. angelarum
176 / Sterna conspicuously covered with plumose or scale-like hairs medially or on lateral margins / Sterna disc nearly bare, not covered with scale-like or plumose hairs, or covered with long, erect hairs / Reversal in C. scioensis; 2 parallelisms: C. torrida, C. (Allocoelioxys) except C. echinata and C. nasuta
201 / T7 apicomedial tooth-like process apically long, narrow and conspicuous / Apicomedial tooth absent / Reversal in C. scioensis; 2 parallelisms: C. (Synocoelioxys) + C. (Allocoelioxys) except C. afra, C. caudata and C. argentea and C. bisoncornua
227 / S8 base triangular, base wide and tapering to acute apex / § / 3 parallelisms: C. (Synocoelioxys), C. polycentris and C. bisoncornua
236 / Gonocoxa apex barbed mesad / Lacking barb mesad / Reversal in C. scioensis; Parallelism in C. afra
All remaining Coelioxys subgenera except C. (Torridapis) + C. (Liothyrapis)