Systematic and taxonomic revision of Emerald and Tigertail dragonflies (Anisoptera: Synthemistidae & Corduliidae)

Libelluloidea is the most speciose superfamily within dragonflies (Odonata: Anisoptera), yet intrafamilial relationships have remained contested for the past 150 years. Here we present a phylogenetic hypothesis for two families within Libelluloidea, Corduliidae (Emeralds), and Synthemistidae (Tigertails) based on comprehensive taxon sampling (Corduliidae: 141/165 species, Synthemistidae: 123/150) for which we generated Anchored Hybrid Enrichment (AHE) high-throughput molecular sequences (10 - 1054 loci). Furthermore, we combined our molecular dataset with 100 discrete morphological characters based on wing, body, nymphal and genitalic characters. Using our molecular data, and an evaluation of morphological characters via ancestral character state reconstruction, we propose a new classification for these taxa.  Here, three new families are erected: Lauromacromiidae fam. nov.,; Macromidiidae fam. nov.,; Aeschnosomatidae fam. nov.. and the status is revised for six families: Pseudocorduliidae stat. rev., Lohmann, 1996; Gomphomacromiidae stat. rev., Tillyard & Fraser, 1940; Austrocorduliidae stat. rev., Lohmann, 1996; Idomacromiidae stat. rev., Tillyard & Fraser 1940; Idionychidae stat. rev., Tillyard & Fraser, 1940; Neophyidae stat. rev., Tillyard & Fraser, 1940. Furthermore, we sink the genus Procordulia Martin, 1907 into the genus Hemicordulia Selys, 1870. Finally, we recover five enigmatic taxa (Archaeophya Fraser, 1959, Libellulosoma Martin, 1907, Austrophya Tillyard, 1909, Apocordulia Watson ,1980, and Cordulisantosia Fleck and Costa, 2007) for which no molecular data was previously available within these new families with high support using a total-evidence approach. Character state reconstructions revealed widespread homology among traditional characters used to identify groups within each family. We estimate the ancestral Libelluloidea possessed a compact anal loop, prominent uniform labial dentition in the nymphs, and a reduced ovipositor. Finally, time-divergence analyses estimate Libelluloidea to have originated within the Late Jurassic, with subsequent families diversifying throughout the Cenozoic.

Methods
Taxon Sampling

We acquired specimens of Corduliidae and Synthemistidae and our outgroups from both freshly caught field-collected and museum specimens. Specimens were hand caught using aerial nets within New South Wales and Victoria Australia during the summer months of January and February 2023. Specimens were placed in glassine envelopes and submerged in acetone for preservation and were transported to the American Museum of Natural History for molecular and morphological analysis. However, most specimens used in our work were sourced from natural history collections. Specimens were sampled from collections in the American Museum of Natural History (AMNH), Florida State Collection of Arthropods (FSCA), Naturalis Biodiversity Center, Natural History Museum (NMNH), Brigham Young University, Monte L. Bean Life Sciences Museum (BYU), Natural History Museum, London UK (NHMUK), the Australian Museum (AM), and the United States National Museum of Natural History (USNM). In total, we sampled 141 of the 165 species of Corduliidae (85%) and 123 of the 150 species of Synthemistidae (82%). We also sampled 9 additional Libelluloidea taxa from other families (Libellulidae: Pantala, Libellula, Orthetrum, Macromiidae: Macromia, Epophthalmia), and families within Cavilabiata (Chlorogomphidae: Chlorogomphus, Cordulegastridae: Cordulegaster, Anotogaster, Neopetaliidae: Neopetalia punctata). Specimen provenance data including locality, date, author, collector, determiner, and sequencing code are listed in Supplemental Table S1. 

DNA Extraction and Sequencing:

We removed the hind leg from each field-collected or museum acquired specimen using sterilized forceps, and extracted DNA using ZYMOBIOMICS DNA miniprep kits (Irvine, CA). We quantified DNA yield using a Qubit 4 fluorometer, and sent to RAPID Genomics (Gainesville, Florida) for library preparation and sequencing. Loci were amplified using modified Anchored Hybrid Enrichment (AHE) probes first implemented in Bybee et al. (2021); the modified probe set consists of 1,306 loci covering approximately 500 kilobases (Goodman et al. 2023). We sequenced loci for representatives of each genus using the full 1,306 probe set (herein referred to as 500kb set), while a subset of 92 loci (herein referred to as 20kb probe set) were sequenced for the remaining species (See Supplemental Table S2)(500kb: 60%, 20kb: 40% of taxa). We re-sequenced several monotypic genera (Synthemistidae: Archaeophya, Austrophya, Apocordulia, Corduliidae: Williamsonia, Cordulisantosia) using the 20kb loci probe set due to failed assembly during the first round of 500kb sequencing.

AHE Assembly and Analysis

We trimmed adaptors from raw reads using fastp (Tang and Wong 2001), and checked for quality using multiQC (Ewels et al. 2016). We followed methods outlined in Breinholt et al. (2018) to assemble and assess orthology for each target capture locus. In brief, we assembled each locus individually using iterative baited assembly with SPAdes (Prjibelski et al. 2020) and a chromosome-length genome assembly of Tanypteryx hageni (Petaluridae) as reference (Tolman et al. 2023). We then screened each locus for orthology by first ensuring that the locus did not have multiple BLAST hits in the reference genome and, secondly, by ensuring best reciprocal hits between the reference and the query sequence.

Phylogenetic Analysis:

We generated multiple sequence alignments for each locus using the ‘MAFFT-linsi’ algorithm in MAFFT v.7.475 (Katoh and Standley 2013) and trimmed alignments using a 0.75 threshold cutoff using trimAI v1.2 (Capella-Gutiérrez et al. 2009). We concatenated the alignment using FASconCAT v1.11 (Kück and Meusemann 2010), and generated an optimal partitioning scheme using relaxed clustering with the model fixed to GTR + G for each subset in IQtree v2.1.3 (Minh et al. 2020). We then selected the best nucleotide substitution model for each subset in the partitioning scheme using ModelFinder (Kalyaanamoorthy et al. 2017) and estimated a maximum likelihood tree (ML). We estimated branch support using SH-like approximate likelihood ratio tests (SH-aLRT) and 1,000 ultrafast bootstrap replicates (UFboot) in IQtree v2.1.3 (Guindon et al. 2010, Minh et al. 2020). Finally, to assess the degree of incomplete lineage sorting, we performed a coalescent-based species tree estimation in ASTRALIII v5.6.1 and estimated branch support using local posterior probabilities (LPP) (Mirarab and Warnow 2015). We identify nodes of high support possessing ML and SH-aLRT values > 95, and LPP values >0.95 We rooted the tree using Neopetalia punctata (Neopetaliidae).

Post-Hoc Modifications to Phylogeny:

Preliminary analyses recovered 38 taxa of varying genera and families that clustered together, forming several odd clades in our phylogeny (See Supplemental Information). These taxa were misplacements (herein referred to as ‘uncertain status’ taxa), and these have been observed in other, previous AHE datasets and are the result of low locus count, low overlap among recovered loci across taxa, contamination, or a combination of factors (Goodman et al. 2025, Goodman et al. 2023). When contamination was exhibited based on other information, those sequences were removed. To improve resolution in our analysis, we omitted those taxa for which there was little to no overlap in recovered loci as several taxa possessed fewer than 10 loci that were recovered among congenerics with high support. After omitting these taxa, our family and genus-level representation decreased, with four monotypic genera no longer present in our analyses (Austrophya, Archaeophya, Apocordulia, and Cordulisantosia). Preliminary phylogenies recovered sequences of Archaeophya and Cordulisantosia within Neocordulia, while sequences of Apocordulia recovered within Idionyx and Somatochlora, and sequences of Austrophya recovered within Libellulidae and sister to Tonyosynthemis; we also observed short fragments and unusual gene alignments. Visual inspection of gene trees suggested other ‘uncertain status’ taxa that were grouping within Neocordulia and Somatochlora, most likely due to contamination. Our final, filtered data set included 211 taxa, down from the 249 taxa originally sequenced (See Supplemental Table S2).

Morphological Analysis:

We collected morphological data from approximately 430 specimens to characterize the variability in states among individuals and across sexes; for all our species we examined at least two specimens unless only one was available (Fig. 1 – 4). When different specimens from a single species varied in their character state, we coded all possible states present in the specimens for that species. We scored 30 wing venation (Fig. 1), 13 external body, 13 accessory genitalic (Fig. 2), 23 nymphal (Fig. 3), and 11 penile characters from Ware (2008) (Fig. 4); we further expanded on this dataset with an additional 10 de novo penile characters described herein totaling 100 characters. Wing-vein terminology followed Riek and Kukalová-Peck (1984); characters were based on previously published characters from Needham and Broughton (1927), Fraser (1957), Miller (1991), Carle (1995), Needham et al. (2000), and Garrison et al. (2006), as well as unpublished characters from Tennessen and May. When we lacked specimens to examine for particular species, we scored adult or nymphal characters from the literature (Theischinger and Watson 1978, 1984, Theischinger 1999, Theischinger and Hawking 2000, Carvalho et al. 2004, Machado 2005a, b, Theischinger and Hawking 2006, Carvalho et al. 2008, Fleck 2008, Theischinger 2009, Pinto and Carvalho 2010, Pinto and Lamas 2010, Fleck 2012a, Fleck 2012b, Fleck and Neiss 2012b, a, Machado 2012, Fleck and Legrand 2013, Theischinger and Endersby 2014b, Fleck 2017, Neiss et al. 2018, Fleck and Juillerat 2019, Roberts et al. 2019, Tennessen 2019, Ehlert and Parise Pinto 2020, Fleck and Haber 2022, Pinto et al. 2022). We mapped characters onto our ML tree under parsimony using the Trace Character option in Mesquite v3.4 (Maddison and Maddison 2007). We were unable to estimate character evolution under maximum likelihood due to the morphological characters possessing more than two states, prompting us to utilize parsimony-based character mapping only.

Further, to assess the degree of impact that specific parts of our morphological dataset  had on relationships in a combined molecular and morphological topology, we first subdivided our morphological characters into discrete groups (wing venation, external body, accessory genitalic, nymphal, and penile), then performed total-evidence Maximum Likelihood phylogenetic analysis combining our molecular dataset with each individual character subset. We applied an MK model of discrete character evolution for our morphology partitions in our ML analyses otherwise using parameters as described above (Lewis 2001) (See supplementary Information). We compared topological differences for each of our trees using Robinson-Foulds (RF) Distance (Robinson and Foulds 1981), and branch length differences using Euclidian Distance (Felsenstein 1984). We then used analysis of variance (ANOVA) to determine statistical differences in topology and branch length between character subsets. In particular, to determine the degree of homoplasy and variation among our morphological data matrix, we compared the rescaled consistency index (Farris 1989) for each character using an ANOVA.

Fossil Selection and Time Divergence Analysis:

We employed fossils as calibrations for divergence time estimation following the best practices outlined by Parham et al. (2012). However, choosing fossils for calibration of odonate divergence time estimation analyses can be challenging due to the restricted suites of characters that are present in most fossils. The taxonomy of odonate fossils relies predominantly on wing characters due to their high preservation potential, and litany of wing venation traits (Fraser and Tillyard 1957). However, wing venation is highly prone to convergence and should be used in conjunction with other traits if available (Fraser and Tillyard 1957, Gloyd 1959, Hennig 1981, Fleck et al. 2008). Amber fossils of adult and nymphal Odonata are rare in the fossil record (Wighton and Wilson 1986, Bechly 1996a, Karr and Clapham 2015, Schädel and Bechly 2016, Zheng and Jarzembowski 2020, Boudet et al. 2023)(See table 1 in Schaedel et al. (2020))(paleodb.com), limiting the possibility for analyses including accessory genitalic, thoracic, penile, or nymphal traits. Kohli et al. (2016) published a list of vetted fossil calibrations for Odonata, as part of the Fossil Calibration Database (fossilcalibrations.org), providing recommendations for fossil selection in our phylogeny; these were updated and expanded upon in Kohli et al. (2021). We employed fossil calibrations for the crown nodes from Kohli et al (2021) for Cavilabiata, Chlorogomphidae + Cordulegastridae, Macromiidae, Corduliidae, Libellulidae, and Corduliidae + Libellulidae. Phylogenetic and age justifications for divergence time estimation of our fossils are outlined in detail in Kohli et al. (2016) and Kohli et al. (2021).

Fossil Validation

We surveyed five additional putative fossils proposed to belong in Synthemistidae as calibration points, extending our sampling beyond Kohli et al. (2021). We used the five principles outlined by Parham et al. (2012) and Ksepka et al. (2015) as best calibration practices. In brief, the five criteria are as follows: 1. Fossil accession number for fossil and referrals, 2. Apomorphy-based or phylogenetic analysis, 3. Reconciliation of morphological and molecular data, 4. Locality and stratigraphic data for fossil taxa 5. Radioisotopic age or numeric age references for fossil (See Table 1 in Goodman et al. (2025) for fossil calibrations).

Two putative fossils were originally assigned to the defunct subfamily Gomphomacromiinae as defined by Tillyard and Fraser (1940), both being estimated as late Jurassic/Early Cretaceous (113 – 125mya) in origin. Mesocordulia boreala, Ren and Guo, 1996 is from Western Liaoning Province, China. The holotype consists of an adult female with all four wings, head, thorax, and abdomen, as well as the paratype consisting of a complete hindwing. Mesocordulia boreala was subsequently placed within the extinct family Araripelibellulidae by Bechly (1996b), in the subfamily Mesocorduliinae. A new specimen of M. boreala was recently described, possessing exceptional preservation of both the forewings and hindwings, as well as several body, head, and external genitalic characters (Nel et al. 2024); several new diagnostic characters identified by Nel prompted the elevation of Mesocorduliinae to family-level. A second fossil is Eocordulia cretacea, Pritykina, 1985 from Western Mongolia. The holotype consists of fragmentary fore and hindwings, there is a paratype of an adult female, and paratypes consisting of the hind wing of an adult male, and posterior end of the abdomen with appendages of an adult male. Eocordulia cretacea was placed within the extinct family Eocorduliidae by Bechly (2007), but not peer-reviewed. Although both taxa exhibit very similar wing venation traits to Synthemistidae, such as a compact (Eocordulia cretacea) or smoothly curving uninflated anal loop (Mesocordulia boreala), both taxa possess unfused sectors of the arculus, a trait present only in non-libelluloid Cavilabiata (Cordulegastridae + Neopetaliidae)(Nel et al. 2024). As such, we chose to exclude these two fossils as calibration points within our time-divergence analysis.

Two other putative fossils for calibration belong to the defunct subfamily Cordulephyidae as defined by Lohmann (1996b). The older fossil is Paleophya argentina, Petrulevičius and Nel 2009, from northwest Argentina and is estimated to be from the early Paleogene (58.7 - 55.8 mya). The holotype consists of a very fragmented hind wing, with anterior and posterior portions missing except between the arculus, anal loop, bridge, and the third postnodal crossvein. The second fossil, Neophya legrandi Nel and Fleck 2013, is from the late Eocene (33.9 – 33.8 mya) from the Isle of Wright. The holotype only consists of the base of the hindwing, between the first antenodal crossvein and the pterostigma, and above the triangle. Paratypes consist of the hindwing base, the costo-apical part of either the fore or hindwing, and the wing apex of the fore or hindwing.

Lastly, Somatochlora brisaci (Nel et al. 1996) is significantly younger, with a Miocene origin (8.7 – 5.3 Ma), discovered in a deposit from Southeastern France. The fossil is a near-complete hindwing except for a few posterior regions of the wing margin missing near the third and fourth medial veins, the cubital (C) and anal (A) veins. Although previous morphological analysis of the wings of S. brisaci failed to recover it within Somatochlora (Goodman et al. 2025), this is an appropriate fossil within Corduliidae.

To determine the utility of these fossil taxa as calibration points, we scored wing-trait data for Neophya legrandi, Paleophya argentina, and Somatochlora brisaci, and performed a total evidence ML phylogeny consisting of our molecular + all morphological characters. Furthermore, we included morphological data for our ‘uncertain status’ taxa for which we had ambiguous molecular placement (n=40) including Austrophya, Archaeophya, Apocordulia, and Cordulisantosia. Finally, we scored the Malagasy species Libellulosoma to infer their placement within Libelluloidea. Previous research has hypothesized its relationship as close to the South American and Australian taxa Aeschnosoma and Pentathemis respectively (Corduliidae)(Fleck and Legrand 2013, Roberts et al. 2019).

All divergence time analyses were conducted on the nucleotide dataset in MCMCtree as implemented in the software package PAML v.4.7a Yang (2007) using an ultrametric (equal branch lengths) version of our ML tree as input. We used our full unpartitioned dataset due to computational limits since our dataset consists of over 1000 loci and 90 partitions were suggested by PartitionFinder. Fossil calibrations were set using uniform prior distributions with hard upper and lower bounds. Our root maximum age was set at 158.1 million years, based on the earliest fossil within Cavilabiata (Juralibellula ningchengensis) (Huang and Nel 2007). We set default parameters for defining prior distribution and used the General Time Reversible (GTR) nucleotide substitution model for calculating the hessian matrix for our dataset. For each scenario, we performed two independent MCMC runs with 500,000 iterations, sampling every 100 trees with a 2000 tree burn-in, and checked for convergence using Tracer v. 1.6 (Drummond and Rambaut 2007). Finally, we examined the prior distributions of each run to ensure reasonable fossil choices and placement on the tree (Warnock et al. 2012). Divergence time estimates, distributions, and outputs are provided in our Supplemental Information.

Bechly, G. 1996a. Morphologische Untersuchungen am Flugelgeader der rezenten Libellen und deren Stammgruppenvertreter (Insecta; Pterygota; Odonata) unter besonderer Berucksichtigung der phylogenetischen Systematik und des Grundplanes der Odonata. Petalura 1-402.

Bechly, G. 1996b. Fossil odonates in Tertiary amber. Petalura 2: 1-15.

Bechly, G. 2007. Phylogenetic Systematics of Odonata.[WWW document]. URL http://www. bernstein. naturkundemuseum-bw. de/odonata/odonato1. htm# palaeodictyopteroida.

Boudet, L., A. Nel, and D. Huang. 2023. A new basal hawker dragonfly from the earliest Late Jurassic of Daohugou, northeastern China (Odonata: Anisoptera: Mesuropetalidae). Hist. Biol. 35: 1267-1273.

Breinholt, J. W., C. Earl, A. R. Lemmon, E. M. Lemmon, L. Xiao, and A. Y. Kawahara. 2018. Resolving relationships among the megadiverse butterflies and moths with a novel pipeline for anchored phylogenomics. Syst. Biol. 67: 78-93.

Bybee, S. M., V. J. Kalkman, R. J. Erickson, P. B. Frandsen, J. W. Breinholt, A. Suvorov, K.-D. B. Dijkstra, A. Cordero-Rivera, J. H. Skevington, and J. C. Abbott. 2021. Phylogeny and classification of Odonata using targeted genomics. Mol. Phylogenet. Evol. 160: 107115.

Capella-Gutiérrez, S., J. M. Silla-Martínez, and T. Gabaldón. 2009. trimAl: a tool for automated alignment trimming in large-scale phylogenetic analyses. Bioinformatics 25: 1972-1973.

Carle, F. 1995. Evolution, taxonomy, and biogeography of ancient Gondwanian libelluloides, with comments on anisopteroid evolution and phylogenetic systematics (Anisoptera: Libelluloidea). Odonatologica 24: 383-424.

CARVALHO, A. L., L. G. V. SALGADO, and P. C. WERNECK-DE-CARVALHO. 2004. Description of a new species of Lauromacromia Geijskes, 1970 (Odonata: Corduliidae) from southeastern Brazil. Zootaxa 666: 1–11-11–11.

Carvalho, A. L., L. G. V. Salgado, and G. Fleck. 2008. Description of the larva of Lauromacromia picinguaba Carvalho, Salgado & Werneck-de-Carvalho 2004, with a key to the genera of Corduliidae larvae occurring in South America (Odonata: Anisoptera). Zootaxa 1848: 57–65-57–65.

Drummond, A. J., and A. Rambaut. 2007. BEAST: Bayesian evolutionary analysis by sampling trees. BMC Evol. Biol. 7: 214.

Ehlert, J., and Â. Parise Pinto. 2020. Additions to the dragonfly genus Lauromacromia, with description of the female of Lauromacromia luismoojeni and new distributional records (Odonata: Corduliidae sl). International Journal of Odonatology 23: 79-91.

Ewels, P., M. Magnusson, S. Lundin, and M. Käller. 2016. MultiQC: summarize analysis results for multiple tools and samples in a single report. Bioinformatics 32: 3047-3048.

Farris, J. S. 1989. The retention index and the rescaled consistency index. Cladistics 5: 417-419.

Felsenstein, J. 1984. Distance methods for inferring phylogenies: a justification. Evolution 16-24.

Fleck, G. 2008. Description of the larva of Lauromacromia picinguaba Carvalho, Salgado & Werneck-de-Carvalho 2004, with a key to the genera of Corduliidae larvae occurring in South America (Odonata: Anisoptera).

Fleck, G. 2012a. The true larva and the female of Aeschnosoma marizae Santos, 1981 (Odonata: Anisoptera: Corduliidae ss). Zootaxa 3488: 80–88-80–88.

Fleck, G. Preliminary notes on the genus Aeschnosoma Selys 1870 (Odonata: Anisoptera: Corduliidae s. str.), pp. 225-228. In Annales de la Société entomologique de France, 2012b. Taylor & Francis.

Fleck, G. 2017. Notes on the genus Navicordulia Machado & Costa, 1995 (Odonata: Anisoptera: Corduliidae s. str.): description of a new species, phylogenetic affinities and aspects of biogeography. Zootaxa 4272: 251-262.

Fleck, G., and U. G. Neiss. 2012a. The larva of the genus Paracordulia Martin, 1907 (Odonata: Corduliidae ss) and a generic key to the larvae of Corduliidae sl occuring in South America. Zootaxa 3412: 62–68-62–68.

Fleck, G., and U. G. Neiss. 2012b. A new species of the genus Aeschnosoma Selys, 1870 (Odonata: Anisoptera: Corduliidae ss). Zootaxa 3159: 47–58-47–58.

Fleck, G., and J. Legrand. 2013. Notes on the genus Libellulosoma Martin, 1906, and related genera (Odonata: Anisoptera: Corduliidae). Zootaxa 3745: 579-586.

Fleck, G., and L. Juillerat. 2019. The genus Navicordulia Machado & Costa, 1995 (Insecta, Odonata, Corduliidae s. str.): new species, identification key for males and data on ecology and distribution. Zoosystema 40: 553-565.

Fleck, G., and W. A. Haber. 2022. Paracordulia calcarulata, new species from Ecuador and notes on the genus Paracordulia Martin, 1907 (Odonata: Anisoptera: Corduliidae s. str.). Zootaxa 5124: 551-564.

Fleck, G., B. Ullrich, M. Brenk, C. Wallnisch, M. Orland, S. Bleidissel, and B. Misof. 2008. A phylogeny of anisopterous dragonflies (Insecta, Odonata) using mtRNA genes and mixed nucleotide/doublet models. Journal of Zoological Systematics and Evolutionary Research 46: 310-322.

Fraser, F. C. 1957. A reclassification of the order Odonata. (No Title).

Fraser, F. C., and R. J. Tillyard. Reclassification of the order Odonata. In 1957. Royal Zoological Society of New South Wales.

Garrison, R. W., N. von Ellenrieder, and J. A. Louton. 2006. Dragonfly genera of the New World: an illustrated and annotated key to the Anisoptera. JHU Press.

Gloyd, L. K. 1959. Elevation of the Macromia group to family status (Odonata). Entomol. News 70: 197-205.

Goodman, A., E. Tolman, R. Uche-Dike, J. Abbott, J. W. Breinholt, S. Bybee, P. B. Frandsen, J. S. Gosnell, R. Guralnick, and V. J. Kalkman. 2023. Assessment of targeted enrichment locus capture across time and museums using odonate specimens. Insect Systematics and Diversity 7: 5.

Guindon, S., J.-F. Dufayard, V. Lefort, M. Anisimova, W. Hordijk, and O. Gascuel. 2010. New algorithms and methods to estimate maximum-likelihood phylogenies: assessing the performance of PhyML 3.0. Syst. Biol. 59: 307-321.

Hennig, W. 1981. Insect phylogeny. John Wiley & Sons Ltd.

Huang, D.-y., and A. Nel. 2007. Oldest'libelluloid'dragonfly from the Middle jurassic of China (Odonata: Anisoptera: Cavilabiata). Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen 63-68.

Kalyaanamoorthy, S., B. Q. Minh, T. K. F. Wong, A. Von Haeseler, and L. S. Jermiin. 2017. ModelFinder: fast model selection for accurate phylogenetic estimates. Nature Methods 14: 587-589.

Karr, J. A., and M. E. Clapham. 2015. Taphonomic biases in the insect fossil record: shifts in articulation over geologic time. Paleobiology 41: 16-32.

Katoh, K., and D. M. Standley. 2013. MAFFT Multiple Sequence Alignment Software Version 7: Improvements in Performance and Usability. Mol. Biol. Evol. 30: 772-780.

Kohli, M., H. Letsch, C. Greve, O. Béthoux, I. Deregnaucourt, S. Liu, X. Zhou, A. Donath, C. Mayer, L. Podsiadlowski, S. Gunkel, M. Ryuichiro, O. Niehuis, J. Rust, T. Wappler, X. Yu, B. Misof, and J. Ware. 2021. Evolutionary history and divergence times of Odonata (dragonflies and damselflies) revealed through transcriptomics. Iscience 24: 103324.

Kohli, M. K., J. L. Ware, and G. Bechly. 2016. How to date a dragonfly: Fossil calibrations for odonates. Palaeontologia Electronica 19: 1-14.

Ksepka, D. T., J. F. Parham, J. F. Allman, M. J. Benton, M. T. Carrano, K. A. Cranston, P. C. Donoghue, J. J. Head, E. J. Hermsen, and R. B. Irmis. 2015. The fossil calibration database—a new resource for divergence dating. Syst. Biol. 64: 853-859.

Kück, P., and K. Meusemann. 2010. FASconCAT: convenient handling of data matrices. Mol. Phylogenet. Evol. 56: 1115-1118.

Lewis, P. O. 2001. A Likelihood Approach to Estimating Phylogeny from Discrete Morphological Character Data. Syst. Biol. 50: 913-925.

Lohmann, H. 1996. Das phylogenetische system der Anisoptera (Odonata). Entomologische Zeitschrift 106: 209-266.

Machado, A. 2005a. Schizocordulia gen. nov. related to Aeschnosom Selys with description of the female and additional data on the male of Schizocordulia rustica (Selys) comb. nov.(Odonata, Corduliidae). Revista Brasileira de Zoologia 22: 775-779.

Machado, A. 2005b. Lauromacromia bedei sp. nov. from the State of Minas Gerais, Brazil (Odonata, Corduliidae). Revista Brasileira de Entomologia 49: 453-456.

Machado, A. 2012. On the generic status of Schizocordulia Machado, 2005 (Anisoptera: Corduliidae). Odonatologica 41: 43.

Maddison, W., and D. Maddison. 2007. Mesquite 2. A modular system for evolutionary analysis 3.

Miller, P. 1991. The structure and function of the genitalia in the Libellulidae (Odonata). Zoological Journal of the Linnean Society 102: 43-73.

Minh, B. Q., H. A. Schmidt, O. Chernomor, D. Schrempf, M. D. Woodhams, A. von Haeseler, and R. Lanfear. 2020. IQ-TREE 2: New models and efficient methods for phylogenetic inference in the genomic era. Mol. Biol. Evol. 37: 1530–1534.

Mirarab, S., and T. Warnow. 2015. ASTRAL-II: coalescent-based species tree estimation with many hundreds of taxa and thousands of genes. Bioinformatics 31: i44-i52.

Needham, J. G., and E. Broughton. 1927. The venation of the Libellulinae (Odonata). Transactions of the American Entomological Society (1890-) 53: 157-190.

Needham, J. G., M. J. Westfall Jr, and M. L. May. 2000. Dragonflies of North America. Scientific Publishers, Inc.

Neiss, U. G., G. Fleck, P. Pessacq, and K. J. Tennessen. 2018. Odonata: Superfamily Libelluloidea, pp. 399-447. In Thorp and Covich's Freshwater Invertebrates. Elsevier.

Nel, A., and G. Fleck. 2013. Dragonflies and damselflies (Insecta: Odonata) from the Late Eocene of the Isle of Wight. Earth Environ. Sci. Trans. R. Soc. Edinb. 104: 283-306.

Nel, A., A. Arillo, and X. Martínez-Delclòs. 1996. New fossil Odonata (Insecta) from the Upper Miocene of France and Spain (Anisoptera and Zygoptera). Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen 167-219.

NEL, A., D.-Y. HUANG, and X.-N. LIAN. 2024. Redescription of the ‘libelluloid’Mesocordulia boreala (Odonata: Mesocorduliidae) from the Lower Cretaceous of China. Zootaxa 5562: 31-37.

Parham, J. F., P. C. Donoghue, C. J. Bell, T. D. Calway, J. J. Head, P. A. Holroyd, J. G. Inoue, R. B. Irmis, W. G. Joyce, and D. T. Ksepka. 2012. Best practices for justifying fossil calibrations. Syst. Biol. 61: 346-359.

Petrulevičius, J. F., and A. Nel. 2009. First Cordulephyidae dragonfly in America: A new genus and species from the Paleogene of Argentina (Insecta: Odonata). Comptes Rendus Palevol 8: 385-388.

Pinto, A. P., and A. Carvalho. 2010. A new species of Lauromacromia (Odonata: Corduliidae) from Southeastern Brazil, with a cladistic analysis of the genus and comments on Neotropical dragonfly biogeography. Zootaxa 2425: 45–68-45–68.

Pinto, Â. P., and C. J. E. Lamas. 2010. Navicordulia aemulatrix sp. nov.(Odonata, Corduliidae) from northeastern Santa Catarina State, Brazil. Revista Brasileira de Entomologia 54: 608-617.

Pinto, Â. P., M. V. O. D. Almeida, and J. Ehlert. 2022. Three names, one species: junior synonyms for the Atlantic Forest emerald dragonfly Navicordulia atlantica (Odonata: Corduliidae ss). Revista Brasileira de Entomologia 66: e20220052.

Prjibelski, A., D. Antipov, D. Meleshko, A. Lapidus, and A. Korobeynikov. 2020. Using SPAdes de novo assembler. Current protocols in bioinformatics 70: e102.

Riek, E. F., and J. Kukalová-Peck. 1984. A new interpretation of dragonfly wing venation based upon Early Upper Carboniferous fossils from Argentina (Insecta: Odonatoidea) and basic character states in pterygote wings. Can. J. Zool. 62: 1150-1166.

Roberts, S. H., L. Barker, L. Chmurova, K.-D. B. Dijkstra, and K. Schütte. 2019. Rediscovery of Libellulosoma minutum in the littoral forests of southeast Madagascar (Odonata: Corduliidae). Notulae odonatologicae 9: 125-172.

Robinson, D. F., and L. R. Foulds. 1981. Comparison of phylogenetic trees. Math. Biosci. 53: 131-147.

Schädel, M., and G. Bechly. 2016. First record of Anisoptera (Insecta: Odonata) from mid-Cretaceous Burmese Amber. Zootaxa 4103: 537-549.

Schaedel, M., P. Mueller, and J. T. Haug. 2020. Two remarkable fossil insect larvae from Burmese amber suggest the presence of a terminal filum in the direct stem lineage of dragonflies and damselflies (Odonata). Rivista Italiana di Paleontologia e Stratigrafia 126.

Tang, X., and D. Wong. FAST-SP: A fast algorithm for block placement based on sequence pair, pp. 521-526. In Proceedings of the 2001 Asia and South Pacific design automation conference, 2001. Association for Computing Machinery, New York, NY, United States.

Tennessen, K. J. 2019. Dragonfly nymphs of North America: An identification guide. Springer.

Theischinger, G. 1999. New and little-known Synthemistidae from Australia (Insecta: Odonata). na.

Theischinger, G. 2009. Identification guide to the Australian Odonata. Department of Environment, Climate Change and Water NSW.

Theischinger, G., and J. Watson. 1978. The Australian Gomphomacromiinae (Odonata: Corduliidae). Aust. J. Zool. 26: 399-431.

Theischinger, G., and J. Watson. 1984. Larvae of Australian Gomphomacromiinae and their Bearing on the Status of the Synthemis Groupof Genera (Odonata: Corduliidae). Aust. J. Zool. 32: 67-95.

Theischinger, G., and J. Hawking. 2000. The larva of Eusynthemis ursula Theischinger (Odonata: Synthemistidae). na.

Theischinger, G., and J. Hawking. 2006. The Complete Field Guide to Dragonflies of Australia.

Theischinger, G., and I. Endersby. 2014. Australian dragonfly (Odonata) larvae: descriptive history and identification. Memoirs of Museum victoria 72: 73-120.

Tillyard, R. J., and F. C. Fraser. A Reclassification of the Order Odonata [based on Some New Interpretations of the Venation of the Dragonfly Wing. In 1938. Royal Zoological Society of New South Wales.

Tolman, E. R., C. D. Beatty, J. Bush, M. Kohli, C. M. Moreno, J. L. Ware, K. S. Weber, R. Khan, C. Maheshwari, and D. Weisz. 2023. A Chromosome-length Assembly of the Black Petaltail (Tanypteryx hageni) Dragonfly. Genome Biol. Evol. 15: evad024.

Ware, J. L. 2008. Molecular and morphological systematics of Libelluloidea (Odonata: Anisoptera) and Dictyoptera. Rutgers The State University of New Jersey, School of Graduate Studies.

Warnock, R. C., Z. Yang, and P. C. Donoghue. 2012. Exploring uncertainty in the calibration of the molecular clock. Biol. Lett. 8: 156-159.

Wighton, D. C., and M. V. Wilson. 1986. The Gomphaeschninae (Odonata: Aeshnidae): new fossil genus, reconstructed phylogeny, and geographical history. Systematic Entomology 11: 505-522.

Yang, Z. 2007. PAML 4: phylogenetic analysis by maximum likelihood. Mol. Biol. Evol. 24: 1586-1591.

Zheng, D., and E. A. Jarzembowski. 2020. A brief review of Odonata in mid-Cretaceous Burmese amber. International Journal of Odonatology 23: 13-21.