Table 2 Fossils supporting each of the node calibrations and the prior distributions selected for the Bayesian time divergence analysis. Node numbers are depicted in Fig. 1

Root

Odonata, Zygoptera, Eosagrionidae, Eosagrion risi †, Early Jurassic, Toarcian, 183–182 Ma (Handlirsch, 1920)

Germany/ Dobbertin, Mecklenburg

PaleoDB 123,987

Uniform prior distribution max = 183

min = 47.8

Calopterygoidea

Odonata, Zygoptera, Calopterygoidea, Calopterygidae Sinocalopteryx shanyongensis †, Eocene, Ypresian (56–47.8 Ma) NIGP 151367 (Lin et al., 2010)

Odonata, Zygoptera, Epallagidae, Labandeiraia europae †, Eocene, Ypresian (56–47.8 Ma)

Odonata, Zygoptera, Epallagidae, Ejerslevia haraldi †, Eocene, Ypresian (56–47.8 Ma) (Zessin, 2011)

Yunnan, China

PaleoDB 113,892

Island of Fur, Denmark

PaleoDB 123,998, 127,173

Ejerslev, Mors, Denmark

PaleoDB 157,041

Outgroup

Euphaeidae

Odonata, Zygoptera, Epallagidae, Labandeiraia americaborealis †, Eocene, Bridgerian (50–46.2 Ma) 31.665A-B (Petrulevicius et al., 2007)

Odonata, Zygoptera, Epallagidae, Litheuphaea coloradensis †, Eocene, Bridgerian (50–46.2 Ma) BMNH Pl II 562 (Petrulevicius et al., 2007)

Odonata, Zygoptera, Epallagidae, Eodichroma mirifica †, Late/Upper Eocene, (37.2–33.9)

(Cockerell 1923)

Odonata, Zygoptera, Epallagidae, Litheuphaea ludwigi †, Eocene, Priabonian (38–33.9 Ma) (Bechly,1990)

Odonata, Zygoptera, Epallagidae, Elektroeuphaea flecki †, Eocene, Priabonian (38–33.9 Ma) (Nel et al., 2013)

Odonata, Zygoptera, Epallagidae, Parazacallites aquisextanea †, Oligocene, Chattian (28.1–23.03 Ma) MNHN IPM-R.06688 (Nel, 1988)

Colorado, USA

PaleoDB = 107,337

Colorado, USA

PaleoDB = 107,337

Texas, USA

PaleoDB = 130,390

Baltic Amber, Russian Federation

PaleoDB = 123,911

Baltic Amber, Poland

PaleoDB = 123,215

Bouches-Du-Rhone, France

PaleoDB 123,943

LogNormal; mean = 50; std. = 0.15

Ingroup/ Polythoridae

Odonata, Zygoptera, Polythoroidea, Bolcathore colorata †, Eocene, Lutetian (47.8–41.3 Ma) MCSNV I.G. 37,582 (Gentilini, 2002)

Odonata, Zygoptera,

Polythoroidea, Bolcathore sp. †, Eocene, Priabonian (38–33.9 Ma) MCSNV I.G. 37,582 (Nel and Fleck, 2014)

Odonata, Zygoptera, Protothore explicata †, Eocene, Bartonian (41.3–38 Ma) (Cockrell, 1930)

Pesciara di Bolca, Italy

PaleoDB = 122,230

Isle of Wight, United Kingdom

PaleoDB = 123,960

California, USA

PaleoDB = 117,537

Uniform prior distribution max = 48

min = 33.9