CLADOENDESIS OF EPHEMEROPTERA
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INDEX OF CHARACTERS

1.3. LARVA:
ABDOMEN AND ITS APPENDAGES
Lateral margins [1.3.1–2], terga [1.3.3–5], sterna [1.3.6–8], selected abdominal segments [1.3.9–18], 
tergalii [1.3.19–59], genital buds [1.3.60], segment X [1.3.61-62], caudalii [1.3.63–67]

[1.3] Abdomen

— large, able to undulate swimming movements: Siphlonurus/fg1 (P), Dipteromimus (P), Ameletus/fg1 (P), Metretopus/fg1 (P), Acanthametropus/fg1 (P), Siphlaenigma (P), Turbanoculata (not all) (VAR), Nesameletus/f1=Metamonius/g1 (P), Vetulata (P), Rallidens (P), Eusetisura (P), Pseudiron (P), Potamanthus/fg1 (P), Euthyplocia/fg1 (P), Fossoriae (P)

Lateral margins of abdominal segments of larva [1.3.1–2]

[1.3.1] Lateral margins of abdominal segments

— expanded: Vetulata (4), Caenotergaliae (not all) (1), Ephemerella/fg1 (not all) (7)

— expanded and bent dorsally: Brachycercus/f1=g3 (4)

— rounded: Fimbriatotergaliae (not all) (10)

— with supra-tergalial projections: part of Epeorus/fg4 (4)

— under tergal expansions: Behningia/fg2 (1)

— III–VII with processes: Palingenia/f2=g1 (6)

— V with pair of lateral incisions: Prosopistoma/f1=g2 ()

— VIII-IX with spines: Cloeon/fg1 (1), Anafroptilum (not all) (3)

[1.3.2] Posterolateral spines of abdominal segments

— absent: part of Radulapalpata (2), Fimbriatotergaliae (not all) (10)

— up to segment VIII, absent on segment IX: Chiloporter (3), Radulapalpata (not all) (2)

— up to segment IX: Arthroplea (P), part of Fimbriatotergaliae (10)

— absent on segment VII (but present on previous and next): Terpides/g1 (not all) (5)

— very long: Ecdyonuroides (1)

Abdominal terga of larva [1.3.3–5]

[1.3.3] Abdominal terga

— with unpaired median projections: Acanthametropus/fg2 (3), Vetulata (3), part of Turbanoculata (VAR) {part of Afroptiloides (VAR), Acanthiops (?), ?Dicentroptilum (?), Afrobaetodes (?), Thraulobaetodes (5), part of Cheleocloeon (VAR), Waynokiops (), part of Baetiella (VAR), Tanzaniops (3), Jubabaetis/g3 (1), part of Baetodes/g3 (VAR), Echinobaetis (), Papuanatula (), }, part of Lachlania (VAR), Notacanthurus (1), part of Epeorus/fg1 (VAR), Neoephemera/fg1 (2), part of Ephemerella/fg1 (19) {Amurella (1), part of Teloganodes/f1=g3 (5), part of Tricoryptera (7)}, part of Leptophlebia/fg1 (VAR) {Poya (?), Peloracantha (?), ...}

— with paired submedian projections: part of Turbanoculata (VAR) {part of Baetiella/fg1 (VAR), Echinobaetis ()}, part of Epeorus/fg1 (VAR), Ephemerella/fg1 (not all) (19) {Timpanoga/fg1 (not all) (P), Ephemerella/fg4 (not all) (P), Hyrtanella/f1=Torleya/g1 (not all) (P) {Hyrtanella/f2=Crinitella/g1 (not all) (VAR)}, Vietnamella (P), Austremerella (P), part of Melanemerella/ fg1 (VAR), Teloganella (P)}

— without median projections: part of Ephemerella/fg1 (19) {part of Timpanoga/fg1 (P), part of Ephemerella/fg4 (P), part of Torleya/g1 (P), part of Hyrtanella/f2=Crinitella/g1 (VAR), Uracanthella (2), part of Melanemerella/fg1 (VAR), Teloganodes/f1-g3 (not all) (7), Tricoryptera (not all) (7)}

— with pair of longitudinal ridges: Behningia/fg1 (1)

— with lateral expansions: Behningia/fg2 (1)

— I with elevated hind margin: Vetulata (1)

— II with unpaired projection: Caenotergaliae (not all) (1)

— VI enlarged and elevated medially: Posteritorna (5)

— VII enlarged and elevated medially: Machadorythus (1)

[1.3.4] Setation of abdominal terga

— no stout setae: Dipteromimus (6), Metretopus/fg2 (1), Metreplecton (1)

— spine-like setae: Siphlonurus/fg1 (6), Siphloplecton (1)

— stout scales in narrow sockets: Acanthametropus/fg1 (7)

— scales in wide sockets: Turbanoculata (not all) (12) {Monocentroptilum (), ... }

— scales in sockets with operculae: Turbanoculata (not all) (12) {Protopatellata (P) (not all) {Indocloeon (17),  ... }, Cloeodes/g1 (), Nigrobaetis/g1 (), Fallceon (), Caribaetis (), Americabaetis (), Mayobaetis (), Guajirolus/g1 (14)}

— without wide scales: part of Turbanoculata (12) {Baetiella/g1 (), Acentrella/fg1 (4), Camelobaetidius/g1 (), Baetodes/g2 (), Deceptiviosa (), Callibaetis/fg3 (4), Paracloeodes ()} 

[1.3.5] Posterior margins of abdominal terga

— without denticles: Parameletus/fg1 (3), Dipteromimus (6), Acanthametropus/fg1 (7)

— denticles fused to integral plate: Coloburiscus/fg1 (5)

Abdominal sterna of larva [1.3.6–8]

[1.3.6] Abdominal sterna (shape)

— with median projections: Acanthametropus/fg2 (3)

— widened: Brachycercus/f1=g3 (4)

— I with finger-like process: Homoeoneuria/g2 (2)

— I with pair of projected plates: Rhithrogena/fg3 (3)

— II–III with setose convexity: Homoeoneuria/g1 (3)

[1.3.7] Setation of abdominal sterna

— no stout setae: Dipteromimus (6), Metretopus/fg2 (1), Metreplecton (1)

— spine-like setae: Siphlonurus/fg1 (6), Siphloplecton (1)

— stout scales: Acanthametropus/fg1 (7)

— with paired transverse rows of hairs: Potamocloeon (), Centroptella/g1 (), Cloeodes/g1 (not all) (1), part of Procloeon/g1

— with setation as on terga – see [1.3.4]

[1.3.8] Posterior margins of abdominal sterna

— denticles fused to integral plate: Coloburiscus/fg1 (5)

Selected abdominal segments of larva [1.3.9–18]

[1.3.9] Segment I (see also [1.3.1–8])

— dorsally with elevated hind margin: Vetulata (1)

— ventrally not expressed: Posteritorna (3)

— ventrally with unpaired process: Homoeoneuria/g2 (2)

— ventrally with projected plates: Rhithrogena/fg3 (3)

[1.3.10] Segment II (see also [1.3.1–8])

— fused with I–VI: Prosopistoma/f1=g2 ()

— dorsally with projection: Caenotergaliae (not all) (1)

— dorsally without projection: Brachycercus/f1=g3 (4)

— ventrally setose (as III): Homoeoneuria/g1 (3)

— ventrally with pair of transverse rows of trichobothria: Cloeodes/g1 (not all) (1)

[1.3.11] Segment III (see also [1.3.1–8])

— fused with I–VI: Prosopistoma/f1=g2 ()

— with lateral processes (as IV–VII): Palingenia/f2=g1 (6)

— ventrally setose (as II): Homoeoneuria/g1 (3)

— ventrally with pair of transverse rows of trichobothria: Cloeodes/g1 (not all) (1)

[1.3.12] Segment IV (see also [1.3.1–8])

— fused with I–VI: Prosopistoma/f1=g2 ()

— with lateral processes (as III–VII): Palingenia/f2=g1 (6)

— ventrally with pair of transverse rows of trichobothria: Cloeodes/g1 (not all) (1)

[1.3.13] Segment V (see also [1.3.1–8])

— fused with I–VI: Prosopistoma/f1=g2 ()

— with pair of lateral incisions: Prosopistoma/f1=g2 ()

— with lateral processes (as III–VII): Palingenia/f2=g1 (6)

— ventrally with pair of transverse rows of trichobothria: Cloeodes/g1 (not all) (1)

[1.3.14] Segment VI (see also [1.3.1–8])

— fused with I–V: Prosopistoma/f1=g2 ()

— with lateral processes (as III–VII): Palingenia/f2=g1 (6)

— enlarged and elevated medially: Posteritorna (5)

— ventrally with pair of transverse rows of trichobothria: Cloeodes/g1 (not all) (1)

[1.3.15] Segment VII (see also [1.3.1–8])

— with lateral processes (as III–VI): Palingenia/f2=g1 (6)

— enlarged, elevated medially: Machadorythus (1)

— without posterolateral spines: Terpides/g1 (5) 

[1.3.16] Segment VIII (see also [1.3.1–8])

— with spines on lateral margins: Cloeon/fg1 (not all) (1)

— with pair of crests: Hyrtanella/f2=Crinitella/g1 (2)

— cylindrical: Tricorygnatha (4)

— without posterolateral spines: Tricorygnatha (4)

[1.3.17] Segment IX (see also [1.3.1–8])

— with spines on lateral margins: Cloeon/fg1 (1)

— without posterolateral spines: Chiloporter (3), Radulapalpata (2), Tricorygnatha (4)

— with posterolateral spines: Arthroplea (P)

— cylindrical: Tricorygnatha (4)

— elongate: Eurylophella/fg2 (1)

— bears gonostyli buds – see [1.3.60]

[1.3.18] Segment X – see [1.3.61–62]

TERGALII
Position of tergalii [1.3.19–22], shape of tergalii [1.3.23–25], margins of tergalii [1.3.26], ribs of tergalii [1.3.27–29], function of tergalii [1.3.30–32], tergalii of selected pairs [1.3.33–59]

Position of tergalii [1.3.19–22]

[1.3.19] Tergalii present on abdominal segments (among all Ephemeroptera)

— I–IX: Euephemeroptera (not all) (6)

— I–VII: Euplectoptera (not all) (2) {Siphlonurus/fg1 (7), Dipteromimus (5), Ameletus/fg1 (VAR), Metretopus/fg1 (3), Acanthametropus/fg1 (5), Ametropus (5), Siphlaenigma (P), Turbanoculata (not all) (VAR), Nesameletus/f1=Metamonius/g1 (9), Oniscigaster/fg2 (P), Ameletopsis/fg1 (4), Rallidens (P), Coloburiscoides (P), Coloburiscus/fg3 (P), Isonychia/fg1 (P), Discoglossata (P), Heptagennota (not all) (P), Fimbriatotergaliae (not all) (6) {Potamanthus/fg1 (P), Euthyplocia/fg1 (P), Fossoriae (3)}, Ephemerella/fg1 (not all) (7) {Vietnamella (P)}, Leptophlebia/fg1 (not all) (7)}

— I–VI: Posteritorna (4), part of Turbanoculata (VAR) {part of Baetiella/fg1 (VAR), Afrobaetodes (1)}, part of Macdunnoa (1), Caenotergaliae (1), Melanemerella/fg1 (not all) (1), part of Leptophlebia/fg1 (7) {part of Traverella/g1 (1), part of Hylister (1), Notophlebia (), part of Adenophlebiodes (1), Massartella (), part of Petersula ()...}

— I–V: part of Turbanoculata (VAR) {Baetodes/g2 (), Asiobaetodes (1)}, part of Melanemerella/fg1 (1)

— I–IV: Tasmanophlebia/g1 (2), part of Melanemerella/fg1 (1), Teloganella (3), (P)

— I and IV–VII: Timpanoga/fg1 (1)

— II–VII: part of Turbanoculata (VAR) {part of Afroptilum/f?=g? (?) Thraulobaetodes (3), part of Baetungulata (2)}, Austremerella (1)–(3), part of Leptophlebia/fg1 (7) {Dilatognathus (2), Isca/fg1 (2), Nesophlebia ()} 

— II–VI: part of Melanemerella/fg1 (1), Teloganodes/f1=g3 (not all) (1), Tricoryptera (not all) (5), (6) {Ephemerythus (not all) (2)}

— II–V: part of Ephemerythus (2), part of Teloganodes/f1=g3 (1), Coryphorus ()

— II–IV: part of Teloganodes/f1=g3 (1)

— III–VII: part of Raptobaetopus/g1, Ephemerella/fg3 (1)

— V–VII: part of Raptobaetopus/g1

[1.3.20] Absent tergalii of anterior pairs (among all Ephemeroptera)

— I: part of Turbanoculata (VAR) {part of Afroptilum/f?=g? (?) Thraulobaetodes (3), part of Baetungulata (2) {Indobaetis (), Indobaetodes ()}}, part of Ephemerella/fg1 (13) {Ephemerella/fg3 (1), Austremerella (1), part of Melanemerella/fg1 (1), Indoganodes (), Teloganodes/f1=g3 (6), Tricoryptera (5), Coryphorus ()}, part of Leptophlebia/fg1 (10) {part in Choroterpes/fg1 (1) {Dilatognathus (2)}, Isca/fg1 (2), Nesophlebia ()} 

— I–II: part of Turbanoculata (VAR) {part of Raptobaetopus/g1}, Ephemerella/fg3 (1)

— I–IV: part of Turbanoculata (VAR) {part of Raptobaetopus/g1}

— I–VII: Murphyella (1)

— II: Ephemerella/fg2 (1)

— II–III: Timpanoga/fg1 (1)

[1.3.21] Absent tergalii of posterior pairs (among all Ephemeroptera)

— VII: Posteritorna (4), part of Turbanoculata (VAR) {part of Baetiella/g1 (VAR), Afrobaetodes ()}, part of Macdunnoa (1), Caenotergaliae (1), Melanemerella/fg1 (not all) (1), Indoganodes (), Teloganodes/f1=g1 (1), Tricoryptera (not all) (6), part of Leptophlebia/fg1 (10) {part of Traverella/g1 (1), part of Hylister (1), Notophlebia (), part of Adenophlebiodes (1), Massartella (), part of Petersula () ...}

— VI–VII: part of Turbanoculata (VAR) {Baetodes/g2 (), Asiobaetodes (1)}, part of Melanemerella/fg1 (1), Teloganella (3), part of Teloganodes/f1=g3 (1), part of Ephemerythus (2), Coryphorus ()

— V–VII: Tasmanophlebia/g1 (2), part of Melanemerella/fg1 (1), part of Teloganodes/f1=g3 (1)

— I–VII: Murphyella (1)

[1.3.22] Places of tergalii attachment transferred

— ventrally: part of Turbanoculata (VAR) {Thraulobaetodes (2), Afrobaetodes (), Baetodes/g3 (1), Asiobaetodes (1)}, Raptoheptagenia (2), Behningia/fg2 (1), part of Leptophlebia/fg1 (VAR) {part of Isca/g1 (3) {Isca/fg2 (1)}

— I ventrally: Geminovenata (1)

— I anteriorly: Potamanthus/fg1 (4), Caenotergaliae (7), Ephemerella/fg1 (not all) (13)

— II–IV anteriorly: Tasmanophlebia/g1 (2)

— VI anteriorly: Posteritorna (5), Caenotergaliae (1)

— VII anteriorly: Ephemera/fg9 (1), Austremerella (3), ??Ulmeritus/g1 ()

Shape of tergalii [1.3.23–25]

[1.3.23] Tergalius of each pair (about specialization of selected pairs – see [1.3.33–59])

— with second lamella or bent lobe – see [1.3.24]

— with fibrillose ventral lobe – see [1.3.25]

— round: Cloeon/fg2 (1), Ametropus (5)

— cup-shaped: Discoglossata (not all) (10)

— with mid-ventral process: Pseudiron (1)

— with dorsal process: Hyrtanella/f2=Crinitella/g1 (1)

— with anterior-proximal lobe: Arthroplea (3)

— secondarily unilamellate: part of Fimbriatotergaliae (6) {Caenoptera (4)}, part of Ephemerella/fg1 (7) {Dicercomyzon (4)}, part of Leptophlebia/fg1 (10) {part of Castanophlebia (), part of Choroterpes/fg2 (2) {Monophyllus (1)}, Magallanella (), VI-VII of Hapsiphlebia ()} 

— unilamellate with processes: Thraulobaetodes (1), Dicercomyzon (4), part of Leptophlebia/fg1 (10) {... }

— pointed apically: Kageronia (7), Stenacron (2)

— enlarged, spread laterally: †"Epeoromimus" (1)

— bidentate: Coloburiscus/fg1 (not all) (6)

— bifurcate: Furcatergaliae (not all) (4)

— bifurcate with pointed apices: Leptophlebia/fg1 (not all) (10) 

— bilamellate, each lamella pointed: Leptophlebia/fg1 (not all) (10) {part of Terpides/fg1 (18), Leentvaaria (P), .......

— bilamellate, each lamella with 1 apical process: Leptophlebia/fg1 (not all) (10) {Needhamella (1), ...}

— bilamellate, each lamella with 3 apical processes: part of Leptophlebia/fg1 (10) {part of Leptophlebia/fg4? (), part of Terpides/fg1 (18) {Fittkaulus (2), Tikuna (2)}, part of Aprionyx (), II-VII in Choroterpes/g2 (not all) (2) {Choroterpes/g3 (1), pm.Euthraulus/g2 (1), Dilatognathus (3)}, Hermanella/g3 (1), Traverina (), ??Miroculis/g2 (), Kimminsula (), ? in Kalbaybaria (), Nathanella (), Radima () ...}

— bilamellate, each lamella with 2 apices: part of Leptophlebia/fg1 (10) {Bibulmena (), Poya ()} 

— bilamellate, each lamella with several (usually more than three) processes: part of Leptophlebia/fg1 (10) {Traverella/g1 (1), Hylister (1), Ulmeritus/g1 (), Askola (), part of Choroterpes/fg1 {Thraulus/g1 (), Nonnullidens/g1 (2), Sangpradubina (1)}, Atopophlebia (), Dactylophlebia (), Isothraulus (, Petersula (), Polythelais ()} 

— bilamellate, each lamella blunt: part of Leptophlebia/fg1 (10) {Celiphlebia (), Microphlebia (), Notophlebia ()} 

— bilamellate, each lamella oval: part of Leptophlebia/fg1 (10) {Needhamella/g1 (1) }

— bifurcate nearly from base: part of Leptophlebia/fg1 (10) {Paraleptophlebia (1) 

— bifurcate, branching at distance from base: part of Leptophlebia/fg1 (10) {Neoleptophlebia (1), Habrophlebiodes (3), Dipterophlebiodes (2), Calliarcys (5), Maheathraulus (), Nesophlebia ()}

— bifurcate, each branch dividing to several processes: part of Leptophlebia/fg1 (10) {Habrophlebia/fg2 (1) }

[1.3.24] Tergalius with additional lamella formed as

— costal lobe bent ventrally: part of Metretopus/fg1 (3)

— anal lobe bent ventrally (see [1.3.25]): I–II in Siphlonurus/fg2 (1), Acanthametropus/fg1 (5), part of Turbanoculata (VAR) {Crassabwa/g2 (), Callibaetis/fg2 (2)}

— anal lobe bent dorsally: III–VII in Siphlurella (1), II–IV in Tasmanophlebia/g1 (2), part of Turbanoculata (VAR) {Cloeon/fg1 (4)}, Hyrtanella/f2=Crinitella/g1 (1)

— outgrowth of ventral surface (see [1.3.25]): part of Ameletopsis/fg1 (4) {Mirawara (2), Chiloporter (4), †Promirara (2)}, Rallidens (5), Bidentiseta (not all) (2) {Branchitergaliae (not all) (3) {Coloburiscoides (P), Isonychia/fg1 (P)}, Furcatergaliae (not all) (5) {Fimbriatotergaliae (6) {Neoephemera/fg1 (P)}}, Ephemerella/fg1 (7)}}

[1.3.25] Ventral lobe (see [1.2.24])

— with marginal processes or fibrillose: part of Ameletopsis/fg1 (4) {Mirawara (2), Chiloporter (4), †Promirara (2)}, Rallidens (5), Branchitergaliae (not all) (3) {Coloburiscoides (P), Isonychia/fg1 (P)}, II–VI in Neoephemera/fg1 (P)

— bifurcate with processes: Ephemerella/fg1 (not all) (7) {Leptohyphes/fg2 (P)}

— bifurcate without processes: part of Ephemerella/fg1 (7) {Allenhyphes (3), Tricorythodes (7)}

— II–III bifurcate: part of Ephemerella/fg1 (7) {part of Melanemerella/fg1 (1), part of Teloganodes/f1=g3 (1)}

— II–IV bifurcate: part of Ephemerella/fg1 (7) {Teloganella (3), part of Teloganodes/f1=g3 (1),  Tricorythopsis (8)}

— II–V bifurcate: part of Ephemerella/fg1 (7) {Austremerella (2), Teloganodes/f1=g3 (not all) (1), Tricorythodes (not all) (7)}

— II–VI bifurcate: Ephemerella/fg1 (not all) (7)

— III–V bifurcate: part of Ephemerella/fg1 (7) {part of Tricorythodes (7)}

— III–VI bifurcate: part of Ephemerella/fg1 (7) {Torleya/g1 (P)}

— III–V bifurcate: part of Ephemerella/fg1 (7) {Ephemerella/fg4 (1)}

— IV–VI bifurcate: part of Ephemerella/fg1 (7) {Timpanoga/fg1 (1)}

— folded as 2 halves: Acanthametropus/fg1 (5)

— lost on all tergalii: Ameletopsis/fg2 (1), Chaquihua (1), Coloburiscus/fg3 (P), Arthroplea (3), Cinygmula (not all) (2), Caenoptera (4)

— diminished or lost on tergalius VII – see [1.3.38] and [1.3.59]

Margin of tergalius [1.3.26]

[1.3.26] Margin of tergalius (about ventral lobe – see [1.3.25])

— with branched processes: Acanthametropus/fg2 (4), Caenotergaliae (1)

— with non-branched processes: Thrailobaetodes (1), Fimbriatotergaliae (not all) (6), Dicercomyzon (4), part of Leptophlebia/fg1 (10)

— with semicircular festoons: part of Rhithrogena/fg3 (3)

— with denticles: Ameletus/fg1 (VAR), Metretopus/fg2 (2), Metreplecton (2), Nesameletus/f1=Metamonius/g1 (9), Rallidens (5), Isonychia/fg1 (8)

— with peculiar setation: Ametropus (5), Coloburiscus/fg1 (not all) (6), Homoeoneuria/g1 (6), Fittkauneuria (3), Epeorus/fg2 (2) {Epeorus/fg3 (2)}, †Siphgondwanus (1)

Ribs of tergalius [1.3.27–29]

[1.3.27] Costal rib of tergalius

— absent: I–II in part of Ameletus/fg1 (VAR), I–III in Metretopus/fg1 (3), part of Turbanoculata (VAR) {Thrailobaetodes (1), Baetodes/g2 ()}, Arthroplea (3), part of Heptagenia/f8=g7 (VAR), Stenonema/fg1 (2), part of Furcatergaliae (5) {part of Fimbriatotergaliae (6) {Caenotergaliae (1)}, Ephemerella/fg2 (2), part of Pantricorythi (P) {III–VI in Leptohyphes/fg1 (1)}, Leptophlebia/fg1 (10)}

— at distance from costal margin: part of Turbanoculata (VAR) {Callibaetis/fg2 (1)}, in part of Nesameletus/f1=Metamonius/g1 (9), Rhithrogena/fg3 (3), I in Epeorus/fg2 (1), Furcatergaliae (not all) (5) {Fimbriatotergaliae (not all) (6), Pantricorythi (not all) (P)}

— sharply curved: Epeiron (1)

— strongly thickened: Coloburiscus/fg1 (not all) (6), †Hexagenites/fg1 (3)

— with projection: Caucasiron (1)

— with denticles: Ameletus/fg1 (VAR), Metretopus/fg2 (2), Metreplecton (2), Nesameletus/f1=Metamonius/g1 (9), Rallidens (5), Isonychia/fg1 (8)

— without denticles: Siphloplecton (2)

— with spine-like setae: Coloburiscus/fg1 (not all) (6)

— with field of curved spine-like setae: Epeorus/fg2 (2)

— with hairs in apical part: Epeorus/fg3 (2)

— secondary: part of Leptophlebia/fg1 (10) {Kirrara (), Deleatidium (?)} 

[1.3.28] Anal rib of tergalius

— absent: Metretopus/fg1 (3), Acanthametropus/fg1 (5), Vetulata (2), part of Turbanoculata (VAR) {Thrailobaetodes (1)}, part of Ameletopsis/fg1 (4) {Ameletopsis/fg2 (1), Chiloporter (4)}, Arthroplea (3), part of Heptagenia/f8=g7 (VAR), part of Furcatergaliae (5) {part of Fimbriatotergaliae (6) {Caenotergaliae (1)}, Ephemerella/fg2 (2), part of Pantricorythi (P), Leptophlebia/fg1 (10)}

— at distance from anal margin behind main trachea: Siphlonurus/fg1 (7) {Siphlonurus/fg2 (1)}, Dipteromimus (5), Ameletus/fg1 (not all) (VAR), Nesameletus/f1=Metamonius/g1 (9), part of Ameletopsis/fg1 (4) {Mirawara (2)}, Rallidens (5), Isonychia/fg1 (8), Stenonema/fg1 (2), Belovius/g1 (1), Furcatergaliae (not all) (5) {Fimbriatotergaliae (not all) (6), Pantricorythi (not all) (P)}, †Hexagenites/fg1 (3), †"Siberiogenites" (1)

— on anal margin: Ameletus/fg1 (not all) (VAR), Ametropus (5), Tetramerotarsata (not all) (12) {Turbanoculata (not all) (VAR)}, part of Ameletopsis/fg1 (4) {Chaquihua (1)}, Heptagennota (not all) (9) {Kageronia (P), Heptagenia/f8=g7 (not all) (VAR), Iron/g1 (P)}

— strongly thickened: Coloburiscus/fg1 (not all) (6)

— arched: Belovius/g2 (1)

— with denticles: Isonychia/fg1 (8)

— with spine-like setae: Coloburiscus/fg1 (not all) (6)

[1.3.29] Additional rib

— behind costal margin: †Promirara (1)

— on anal margin: part of Nesameletus/f1=Metamonius/g1 (9) {Nesameletus/f2=Metamonius/g2 (5)}, Rallidens (5), Isonychia/fg1 (8)

— in front of main trachea: part of Tetramerotarsata (12)

— on costal branch of ventral lobe: Leptohyphes/fg1 (1)

Function of tergalii [1.3.30–32]

[1.3.30] Ability of tergalii to respiratory movements

— present: Siphlonurus/fg1 (P), Metretopus/fg1 (P), part of Turbanoculata (VAR) {Indocloeon (19), Rhithrocloeon/fg1 (3), Dabulamanzia (), Crassabwa/g2 (8), Demoulinia (), part of Cloeon/fg1 (), Centroptilum (), Cheleocloeon () Afrobaetodes (), Callibaetis/fg1 (7), Centroptella ()}, Nesameletus/f1=Metamonius/g1 (P), Vetulata (P) {Tasmanophlebia/g1 (2)}, Chaquihua (1), Heptagenia/f5=g4 (P), Fimbriatotergaliae (6) {Caenotergaliae (1)}, Ephemerella/fg1 (7), Leptophlebia/fg1 (not all) (10)

— absent: Ameletus/fg1 (4), part of Turbanoculata (VAR) {Baetungulata (2), Baetopus/g1 (), part of Cloeodes/g1 (), Paracloeodes/g1 (), Monocentroptilum (), Susua (2)}, Eusetisura (7) {Isonychia/fg1 (8)}, Cinygma (8), Rhithrogena/fg1 (6), part of Leptophlebia/fg1 (10)

— produce asymmetric water flow: Caenoptera (4)

— lost by gill opercula – see [1.3.32]

— lost by tergalius I – see [1.3.33]

[1.3.31] Specialization of tergalii

— form sucking disc: Rhithrogena/fg3 (3), Iron/g1 (1), part of Leptophlebia/fg1 (10) {Kirrara (), Lepeorus (), ...}

— form gill opercula – see [1.3.32]

[1.3.32] Tergalii forming gill opercula (among all Ephemeroptera)

— I (see [1.3.33]): Vetulata (1) {Tasmanophlebia/g1 (2)}, part of Leptophlebia/fg1 (10) {Adenophlebiodes (1)} 

— II (see [1.3.39]): Posteritorna (4), Caenotergaliae (1), part of  Ephemerella/fg1 (7) {Melanemerella/f1=Teloganodes/g1 (1), Ephemerythus (2), Machadorythus (5), Leptohyphes/fg1 (1), Coryphorus ()}

— III (see [1.3.45]): part of  Ephemerella/fg1 (7) {part of Ephemerella/fg3 (P) {part of Torleya/g1 (VAR), part of Hyrtanella/f2=Crinitella/g1 (1)}}

— IV (see [1.3.50]): part of  Ephemerella/fg1 (7) {Timpanoga/fg2 (1) {Eurylophella/fg1 (1)}}

Tergalii of certain pairs [1.3.33–59]

[1.3.33] Tergalius I (unlike others)

— absent: see [1.3.20]

— simplified: Choroterpes/fg1 (not all) (1)

— does not make respiratory movements: Choroterpes/fg1 () {Nonnullidens/g1 ()}, Indialis/g1 (), part of Kimminsula/g1 (), Nathanella ()

— attached ventrally: Geminovenata (1)

— consists of fibrillose lobe only: Homoeoneuria/g2 (3), Fittkauneuria (2)

— specialized as gill operculum: part of Vetulata (1) {Tasmanophlebia/g1 (2)}, part of Leptophlebia/fg1 (10) {Adenophlebiodes (1)} 

— specialized similar to gill operculum: part of Vetulata (1) {Oniscigaster/fg2 (1)}

— stick-like: [Classifications of Furcatergaliae I] (1), part of Fimbriatotergaliae (6) {Potamanthus/fg1 (4), Caenotergaliae (7)}, Ephemerella/fg1 (not all) (13) {Timpanoga/fg1 (not all) (P), Vietnamella (P), Melanemerella/fg1 (not all) (1), Teloganella (P)}

— unilamellate: part of Fimbriatotergaliae (6) {Behningia/fg1 (15), Choroterpes/fg1 (not all) (1), Maheathraulus ()}

— vestigial unilamellate: part of Fimbriatotergaliae (6) {Litobrancha (1), Anagenesia/g1 (3), Polymitarcys/f2=Ephoron/g3 (3), Tortopus (3)}

— bifurcate, with non-widened branches: Leptophlebia/fg4 (1), part of Thraulus/g1 ()

— vestigial bilamellate: Fimbriatotergaliae (not all) (6) {Euthyplocia/fg1 (9), Ichthybotus (3), Ephemera/fg9 (not all) (4) {Ephemera/fg10 (P), Hexagenia/fg2 (P) Eatonica/g2 (P), Eatonigenia (P)}, Cryptoprosternata (not all) (6) {Pentagenia (P), Palingenia/f4=g3 (P), Campsurus/fg3 (P), Asthenopus (P)}}

— longest, with straight costal margin and dissected anal margin: Posteritorna (4)

— paddle-shaped: Dabulamanzia (), Susua (), Cheleocloeon (20)

— banana-like, curved posteriorly: Ecdyonurus/fg1 (3)

— with lobe anteriad of costal rib: part of Nesameletus/f1=Metamonius/g1 (9), Rhithrogena/fg3 (3), Epeorus/fg2 (1)

— with lobe anteriad of costal rib strongly widened: Rhithrogena/fg3 (3), Iron/g1 (1) {Ironopsis/g1 (3)}

— with anal lobe bent ventrally: Crassabwa/g2 () 

[1.3.34] Tergalii I and II (unlike others)

— absent: see [1.3.20]

— without ribs: part of Ameletus/fg1 (VAR)

— without denticles on costal rib: Rallidens (5)

— with anal lobe bent ventrally: Siphlonurus/fg2 (1)

— bipointed: Siphlonurus/fg3 (1)

[1.3.35] Tergalii I–III (unlike others)

— without costal rib: Metretopus/fg1 (3)

[1.3.36] Tergalii I–IV

[1.3.37] Tergalii I–V

[1.3.38] Tergalii I–VI (unlike VII)

[1.3.39] Tergalius II (unlike others)

— absent: see [1.3.20]

— specialized as gill operculum: Posteritorna (4), Caenotergaliae (1), Melanemerella/f1=Teloganodes/g1 (1), Ephemerythus (2), Machadorythus (5), Leptohyphes/fg1 (1), Coryphorus ()

— coupled with its pair: Neoephemera/fg1 (1)

— with costal flap: Leptohyphes/fg1 (not all) (1) {Allenhyphes (P), Tricorythodes (P)}

— with spine-like process: Leptohyphes/fg2 (1)

— with one process on each branch of ventral lamella: Tricorythopsis (8)

— ventrally with microtrichia: Caenoptera (3)

— with microtrichia simple: Brachycercus/f1=g3 (P)

— with microtrichia plumose: Caenis/f3=g1 (1)

— with Y-rib: part of Caenotergaliae (1) {Caenoptera (not all) (18) {Afrocaenis (P)}}

— without Y-rib: Caenopsella/g2 (1)

— with Y-rib projected medially: Clypeocaenis/fg1 (2)

— strongly widened anteriorly: Kirrara ()

[1.3.40] Tergalii II–III (unlike others)

— absent: see [1.3.20]

— with ventral lobe bifurcate – see [1.3.25]

[1.3.41] Tergalii II–IV (unlike others)

— with anal lobe bent dorsally: Tasmanophlebia/fg1 (2)

— with ventral lobe bifurcate – see [1.3.25]

[1.3.42] Tergalii II–V (unlike others)

— with ventral lobe bifurcate – see [1.3.25]

[1.3.43] Tergalii II–VI (unlike others)

[1.3.44] Tergalii II–VII (unlike I)

[1.3.45] Tergalius III (unlike others)

— specialized as gill operculum: part of Ephemerella/fg3 (P) {part of Torleya/g1 (VAR), part of Hyrtanella/f2=Crinitella/g1 (1)}

— with marginal processes branched: Madecocercus (2)

— with dorsal lobe bifurcate: part of Teloganodes/f1=g3 (1)

[1.3.46] Tergalii III–IV (unlike others)

— with dorsal lobe bifurcate: part of Teloganodes/f1=g3 (1)

— with ventral lobe bifurcate – see [1.3.25]

[1.3.47] Tergalii III–V (unlike others)

— with dorsal lobe bifurcate: Teloganodes/f1=g3 (not all) (1)

— with ventral lobe bifurcate – see [1.3.25]

— with dissected margins: Posteritorna (4)

— with anal rib only: Leptohyphes/fg1 (1)

[1.3.48] Tergalii III–VI (unlike others)

— hidden under gill opercula: Caenotergaliae (1), Melanemerella/f1=Teloganodes/g1 (1), part of Ephemerythus (2), Machadorythus (5), Leptohyphes/fg1 (1)

— truncate, with trifolium: Ephemerella/fg2 (not all) (2)

— with branching processes: Caenotergaliae (1)

— with ventral lobe bifurcate – see [1.3.25]

[1.3.49] Tergalii III–VII (unlike others)

— without ventral lamella: Siphlonurus/fg2 (1)

— with dorsal lamella: Siphlurella (1)

— with denticles on costal rib: Rallidens (5)

[1.3.50] Tergalius IV (unlike others)

— specialized as gill operculum: part of Ephemerella/fg1 (7) {Timpanoga/fg2 (1) {Eurylophella/fg1 (1)}}

— without ventral lobe: part of Ephemerella/fg1 (7) {part of Melanemerella/f1=Teloganodes/g1 (1)}

[1.3.51] Tergalii IV–V (unlike others)

[1.3.52] Tergalii IV–VI (unlike others)

— with non-branched processes: Madecocercus (2)

— with ventral lobe bifurcate – see [1.3.25]

[1.3.53] Tergalii IV–VII (unlike others)

— with ventral lobe: part of Ephemerella/fg1 (7) {Timpanoga/fg1 (1)}

— with costal rib: Metretopus/fg1 (3)

— with additional dorsal lamella: part of Hyrtanella/f2=Crinitella/g1 (1)

— hidden under gill opercula: part of Ephemerella/fg3 (P) {part of Torleya/g1 (VAR), part of Hyrtanella/f2=Crinitella/g1 (1)}

— unilamellate: Hapsiphlebia () 

[1.3.54] Tergalius V (unlike others)

— without ventral lobe: part of Ephemerella/fg1 (7) {part of Ephemerythus (2), Teloganella (3), part of Teloganodes/f1=g3 (2)}

[1.3.55] Tergalii V–VI (unlike others)

— without ventral lobe: part of Ephemerella/fg1 (7) {part of Ephemerythus (2)}

[1.3.56] Tergalii V–VII (unlike others)

— absent: see [1.3.21]

— hidden under gill opercula: Timpanoga/fg2 (1)

— with additional dorsal lamella: part of Hyrtanella/f2=Crinitella/g1 (1)

[1.3.57] Tergalius VI (unlike others)

— attached anteriorly: Posteritorna (5), Caenotergaliae (1)

— blade-like: Posteritorna (4)

— diminished: Macdunnoa (1)

— with incised posterior-distal margin: Epeiron (1)

— without ventral lobe: part of Ephemerella/fg1 (7) {Melanemerella/fg1 (not all) (1), Ephemerythus (not all) (2), Teloganodes/f1=g3 (not all) (2), part of Leptohyphes/fg1 (1)}

— with non-bifurcate ventral lobe: part of Ephemerella/fg1 (7) {Ephemerella/fg4 (1), Austremerella (2)}

[1.3.58] Tergalii VI–VII (unlike others)

— absent: see [1.3.21]

— with additional dorsal lamella: part of Hyrtanella/f2=Crinitella/g1 (1)

[1.3.59] Tergalius VII (unlike others)

— absent: see [1.3.21]

— appear first: Ephemerella/fg1 (7a)

— attached anteriorly: Ephemera/fg9 (1), Austremerella (3)

— enlarged: †Promirara (1), †Hexagenites/fg1 (3)

— vestigial: Macdunnoa (not all) (1)

— without fibrillose ventral lobe: part of Coloburiscoides (P), Kageronia (6), part of Heptagenia/f8=g7 (VAR), Stenonema/fg1 (3), Ecdyonurus/fg1 (not all) (6), Ironodes (2)

— with non-bifurcate ventral lobe: Ephemerella/fg1 (not all) (7)

— with longitudinal fold: Rhithrogena/fg3 (3), Iron/g1 (1)

Genital buds of larva [1.3.60]
internal structure [2.3.9]

[1.3.60] Genital buds of mature male larva

— protogonostyli absent (internal structure see [2.3.9]): part of Turbanoculata (13), Caenis/f3=g1 (2)

— protopenis absent: Liberevenata (6), Caenotergaliae (3)

— protopenis with ventral plates prominent: Metreletus (3)

— protopenis with ventral plates not expressed: Ameletus/fg2 (2)

— protopenis with gonoducts lined by cuticle: Hermanellonota (2), Notophlebia (6), ?Meridialaris (), Nousia/g1 ()

Abdominal segment X of larva [1.3.61–62]

[1.3.61] Abdominal tergite X

— with apodemes: Prosopistoma/f1=g2 ()

— with angles reaching cerci ventro-laterally: Geminovenata (8), Fossoriae (5), Caenotergaliae (12)

[1.3.62] Paraproct

— elongate: Prosopistoma/f1=g2 ()

— with spine: Siphlonurus/fg2 (2), Metretopus/fg1 (7), Siphluriscus (3), Vetulata (7), Rallidens (8)

— with projection on posterior margin: Takobia/g1 (), Indobaetis (), gr.balkei (in Labiobaetis/f2=g1) (?)

— separated from cercotractor: Geminovenata (8), Fossoriae (5), Caenotergaliae (12)

Caudalii of larva [1.3.63–67]

[1.3.63] Caudalii of larva (see also [1.3.64–65])

— retractile: Prosopistoma/f1=g2 ()

— thickened in male: [Classifications of Furcatergaliae IIb] (7), Caenoptera (14), Tricorygnatha (10), Ephemerythus (6),  Leptohyphes/fg1 (8)

— with fused denticles: Coloburiscus/fg1 (5)

— with whorls of stout setae: Heptagenia/f5=g4 (2)

— without whorls of stout setae: Raptoheptagenia (5), Cinygma (9), Rhithrogena/fg1 (7)

[1.3.64] Paracercus of larva (see also [1.3.53])

— absent: part of Oligoneuria/f4=g5 (6)

— non-segmented: part of Turbanoculata (VAR) {Micksiops, Afroptiloides/g2 (), part of ??Baetis/fg9 (VAR), Baetiella/g1 (), part of Acentrella/fg1 (5), Camelobaetidius/g2 ()}, Murphyella (2), part of Oligoneuriella/g1 (VAR), part of Oligoneuria/f4=g5 (6) {Lachlania (3)}, part of Pentamerotarsata (6) {Epeorus/fg1 (2), Acanthomola (2), Anepeorus (3)}, part of Ephemerella/fg1 (P) {Teloganodes/f1=g3 (2), Dicercomyzon (5)}

— short multisegmented: part of Turbanoculata (VAR) {Deceptiviosa (), part of ?? Baetis/fg10 (VAR), Baetiella (?), part of Acentrella/fg1 (5), Baetodes (?)}, Coloburiscus/fg2 (2) (not all) {Coloburiscus/fg3 (P)}, Chromarcys (1), part of Oligoneuriella/g1 (VAR), Fittkauneuria (P), part of Leptophlebia/fg1 (P)

— long multisegmented: Siphlonurus/fg1 (P), Dipteromimus (P), Ameletus/fg1 (P), Metretopus/fg1 (P), Acanthametropus/fg1 (P), Ametropus (P), Siphlaenigma (P), Turbanoculata (not all) (VAR) {?........., Cloeon/fg1 (VAR), Callibaetis/fg1 (P), Cloeodes/g1 (P), Nigrobaetis/g2 (P), Fallceon (P), Caribaetis (P), Americabaetis (P), ??Baetis/fg10 (not all) (VAR), part of Acentrella/fg1 (5), Labiobaetis/f1=Pseudopannota/g1 (P), Fallceon (), Caribaetis (), Americabaetis (P), Mayobaetis (P), Edmundsiops (P)}, Nesameletus/f1=Metamonius/g1 (P), Vetulata (P), Ameletopsis/fg1 (P), Rallidens (P), Coloburiscoides (P), Isonychia/fg1 (P), Oligoneuriella/g1 (not all) (VAR), Homoeoneuria/g1 (P), Elassoneuria/g1 (P), Oligoneuria/f5=g6 (3), Pseudiron (P), Pentamerotarsata (6) (not all) {Paegniodes (P), Rhithrogena/fg2 (P)}, Fimbriatotergaliae (P), Ephemerella/fg1 (not all) (P), Leptophlebia/fg1 (not all) (P)

— longer than cerci: Caudatella (1)

— with ventral villareas: Baetodes/g1 (3)

[1.3.65] Cerci of larva (see also [1.3.53])

— contiguous basally: part of Oligoneuria/f4=g5 (6) {Lachlania (3)}

— with stretched bare last segments: part of Centroptilum/g1 (), Cloeon/fg2 (), Similicloeon (), Intercloeon ()}, Pseudiron (P), 

— without elongate bare last segments: Pseudocentroptilum (2), Procloeon/g1 (1) 

— with enlarged lateral spine-like seta on each segment: Mayobaetis ()

— in distal part with enlarged lateral spine on each segment: Procloeon/g1 (1)

[1.3.66] Primary swimming setae

— lost: part of Turbanoculata (VAR) {Baetiella (), part of Acentrella/fg1 (2), part of Baetodes ()}, Coloburiscus/fg2 (2), part of Pentamerotarsata (6) {part of Kageronia (VAR), Leucrocuta/g1 (1), Atopopus/g1 (2), Cinygma (10), Cinygmula (1), Epeorus/fg1 (2)}, part of Furcatergaliae (6) {part of Fossoriae (P) {Campsurus/fg1 (12)}}

— vestigial: part of Turbanoculata (VAR) {...?, Baetodes (not all) ()}, Pentamerotarsata (not all) (6) {Arthroplea (P), part of Kageronia (VAR), Heptagenia/f7=g6 (P), Ecdyonurus/fg2 (P), Afghanurus/g2 (P), Paegniodes (P), Rhithrogena/fg3 (P)}

— dense: Euephemeroptera (not all) (5) {Posteritorna (P), Siphlonurus/fg1 (P), Dipteromimus (P), Ameletus/fg1 (P), Metretopus/fg1 (P), Acanthametropus/fg1 (P), Ametropus (P), Siphlaenigma (P), Turbanoculata (not all) (VAR) {........................., Cloeon/fg1 (P), Callibaetis/fg1 (P)}, Nesameletus/f1=Metamonius/g1 (P), Vetulata (P), Ameletopsis/fg1 (P), Rallidens (P), Eusetisura (not all) (P) {Coloburiscoides (P)}, Pseudiron (P), Furcatergaliae (not all) (6) {Fossoriae (not all) (P)}, †Hexagenites/fg1 (P), †"Stackelbergisca" (P), †"Proameletus" (P), †Mesogenesia/g1 (P), †"Epeoromimus" (P), †"Mogzonurella" (P), †"Siberiogenites" (P), †"Australurus" (P), †"Dulcimanna" (P), †"Albisca" (P), †"Siphgondwanus" (P)}

— differentiated to thick proximal part and thin distal part: Indocloeon (21), .....???? 

[1.3.67] Secondary swimming setae

— present: Posteritorna (13), Ametropus (6), part of Turbanoculata (VAR) {part of Centroptella (?)}, part of Vetulata (P), Ameletopsis/fg1 (not all) (5) {Ameletopsis/fg2 (2), Chiloporter (5), Chaquihua (2)}, part of Pentamerotarsata (6), Furcatergaliae (not all) (6) {Potamanthus/fg1 (P), Euthyplocia/fg1 (P), Fossoriae (P) {Campsurus/fg1 (12), †"Siphangarus"}, Potamanthellus/g1 (4), Ephemerella/fg5 (P), Terpides/fg1 (1)}

— absent: Siphlonurus/fg1 (P), Dipteromimus (P), Ameletus/fg1 (P), Metretopus/fg1 (P), Acanthametropus/fg1 (P), Turbanoculata (not all) (VAR), Nesameletus/f1=Metamonius/g1 (P), Vetulata (not all) (P), part of Ameletopsis/fg1 (5) {Mirawara (P)}, Rallidens (P), Siphlaenigma (P), Eusetisura (P), Pentamerotarsata (not all) (6), Pseudiron (P), part of Furcatergaliae (6)