Panephemeroptera

Nymph of Mesogenesia petersae, from Staniczek et al. (2011); scale bar = 2 mm.

Belongs within: Palaeoptera.
Contains: Permoplectoptera, Furcatergalia, Pisciformia.

The Panephemeroptera are the clade of insects including the modern Ephemeroptera, mayflies, and their fossil relatives. Mayflies spend the greater part of their life cycle as aquatic nymphs (called naiads), with the emergent stage of their life-cycle (including two instars, the sub-adult subimago and the fully mature imago) being non-feeding and short-lived.

What is the sound of one mayfly fossilising?
Published 21 February 2008

Actually, two mayflies. That is, unless they’re not mayflies.

The Triassic is apparently not a fantastic time, insect-wise. Fossil insects from the Triassic are fairly few and far between. Needless to say, this is really annoying, because it was probably a fairly significant time in insect evolution. The giant insects of the Palaeozoic were no more—instead, it was about this time that many of the modern insect orders stepped in to take their place (Grimaldi & Engel 2005). An unfortunately brief paper by Krzeminski & Lombardo (2001) gives us just a couple of pieces of the puzzle, but it’s debatable just what we can do with them.

The maybe-mayfly Tintorina was described by Krzeminski & Lombardo from two specimens (unfortunately, while the name Tintorina triassica appears in the abstract, the name used in the body of the article is Tintorina meridensis—I’m not sure, but I think the latter would be the correct name). The holotype retains most of the body (the head is missing), two of the wings and a few bits of leg. The paratype is just a pair of wings and a fragment of body. Though fragmentary, this collection does not put us too badly off. A large percentage of insect fossil species are only known from the wings, and the pattern of venation therein is hence the most commonly used suite of characters for distinguishing taxa. Krzeminski & Lombardo assign Tintorina to a new family of Ephemeroptera. They cite the wing venation and the general body shape as their reason for doing so, but unfortunately do not note exactly which features of the venation they refer to. Features such as the absence of a humeral vein (a small vein near the base of the wing) indicate that, if Tintorina is related to Ephemeroptera, it must lie outside the crown group. The only author to specifically comment on Tintorina since seems to be Kluge (2004), who concurred in the overall similarity of venation with Ephemeroptera, but also noted a couple of significant differences. As a result, Kluge moved Tintorina to Pterygota incertae sedis.

Mayflies in their spring
Published 12 November 2012
Armoured mayfly Baetisca obesa, photographed by Jason Neuswanger.

Mayflies have occasionally put in an appearance here at Variety of Life. In this post, I thought that I’d look briefly at the fossil context of mayflies.

The basalmost relationships among insects have been subject to some discussion over the years, but the current majority view is probably that mayflies were the first of the living winged insect lineages to diverge from the rest. Evidence for this is their retention of some plesiomorphic features such as the presence of three caudal filaments at the end of the abdomen, and a sliding rather than fixed inner mandibular articulation in the nymphs (adult mayflies don’t have functional mouthparts). Mayfly nymphs, offhand, are known as naiads. Naiads were originally supposed to be nymphs that inhabited freshwater springs, so at some point the term ‘naiad’ was transferred from this:

Hylas and the Nymphs, by John William Waterhouse, in which our hero is fatally tempted by a septet of skinnydipping broads.

to this:

Drunella cornuta, photographed by Jonas Insinga.

Which I’m sure came as something of a disappointment to Hylas (though, of course, had Hylas been more disappointed, he may have also been less dead).

There is some uncertainty whether aquatic nymphs are ancestral or derived for winged insects. However, mayflies were spending the first part of their lives in water by at least the Permian (Kluge & Sinitshenkova 2002; Grimaldi & Engel 2005). Representatives of the mayfly crown group (i.e. the group stemming from the most recent common ancestor of all living mayflies) are not known until the Jurassic; earlier species all belong to the stem group. The Carboniferous Syntonopterodea may also be stem-mayflies, but in superficial appearance the large, broad-winged syntonopterodeans may have looked more like the contemporary palaeodictyopteroids.

Reconstruction of Protereisma permianum, one of the best known of the Permian stem-mayflies, via here.

The Permian and Jurassic Ephemeroptera themselves had some notable differences from crown-group mayflies. Modern mayflies have heteronomous wings, with the fore- and hind wings differing in size (in some mayflies, the hind wings have almost disappeared entirely). Permian mayflies, in contrast, had homonomous wings, with the two pairs more or less identical; the hind wings became shortened in Triassic stem-mayflies (Grimaldi & Engel 2005). At least some stem-mayflies also retained well-developed mouthparts as adults; this suggests that they may well have lived longer as adults than modern mayflies. While Grimaldi & Engel (2005) included Permian and Triassic species in the Ephemeroptera, Staniczek et al. (2011) restricted that name to the crown group and its nearest and dearest, placing most of Grimaldi & Engel’s stem-group ‘Ephemeroptera’ into an extinct clade Permoplectoptera.

Systematics of Panephemeroptera
<==PanephemeropteraSBG11
    |--SyntonopteroideaSBG11
    |    |--Miracopteron [Miracopteridae]SBG11
    |    |    `--M. mirabileR02
    |    `--SyntonopteridaeGE05
    |         |--Syntonoptera schuchertiRJ93
    |         |--GallolithoneuraSBG11
    |         |--AnglolithoneuraSBG11
    |         `--LithoneuraGE05
    |              |--L. lameereiGE05
    |              `--L. mirificaR02
    `--Ephemerida [Ephemeropteroidea, Plectoptera, Protereismatina, Reticulata]SBG11
         |  i. s.: Turphanella Demoulin 1954KS02
         |         SiphoplectonKS02
         |         GeisfeldiellaKS02
         |         AphelophlebodesKS02
         |         SiphangarusS02
         |         Bolbonyx ludibriosusS02
         |         Mesopalingea leridaS02
         |         CratoligoneuriellaS02
         |         Stenonema interpunctatumM47
         |           |--S. i. interpunctatumM47
         |           |--S. i. canadenseM47
         |           |--S. i. frontaleM47
         |           `--S. i. heterotarsaleM47
         |         Siphlonisca aerodromiaMH96
         |         Campylocia ancepsD70
         |         Dolania americanaK-P83
         |         Ephoron virgo (Olivier 1791)M86
         |         ParameletusK03
         |           |--P. chelifer Bengtsson 1908K03
         |           `--P. columbiaePC91
         |         Tintorina Krzeminski & Lombardo 2001KL01 [TintoriniidaeGE05]
         |           `--*T. meridensis Krzeminski & Lombardo 2001 [=T. triassica Krzeminski & Lombardo 2001 (n. n.)]KL01
         |--PermoplectopteraSBG11
         `--HeptabranchiaSBG11
              |--Mickoleitiidae [Coxoplectoptera]SBG11
              |    |--Mickoleitia Staniczek, Bechly & Godunko 2011SBG11
              |    |    `--*M. longimanus Staniczek, Bechly & Godunko 2011SBG11
              |    `--Mesogenesia Tshernova 1977SBG11, KS02 [incl. Archaeobehningia Tshernova 1977SBG11]
              |         |--‘Archaeobehningia’ edmundsiRJ93
              |         `--M. petersae Tshernova 1977SBG11
              `--Ephemeroptera [Euephemeroptera, Euplectoptera]SBG11
                   |  i. s.: Chironetes albimanicatusRD77
                   |--Ephemerina [Anteriotorna, Bidentiseta, Schistonota]KS02
                   |    |--FurcatergaliaGE05
                   |    `--PisciformiaGE05
                   `--Baetiscina [Posteritorna, Prosopistomatoidea]KS02
                        |--Baetisca [Baetiscidae, Baetiscoidea, Carapacea]PC91
                        `--ProsopistomatidaeKS02
                             |--Myanmarella rossiKS02
                             `--ProsopistomaPC91

*Type species of generic name indicated

References

[D70] Demoulin, G. 1970. Contribution a la connaisance de ephemeropteres du Miocene. I. Siphlurites explanatus Cockerell. Bulletin de l’Institut Royal des Sciences Naturelles de Belgique 46 (5): 1–4.

[GE05] Grimaldi, D., & M. S. Engel. 2005. Evolution of the Insects. Cambridge University Press: New York.

[K03] Kluge, N. J. 2003. About evolution and homology of genital appendages of insects. Trudy Russkogo Entomologicheskogo Obshestva [Proceedings of the Russian Entomological Society] 74: 3–16.

Kluge, N. 2004. The Phylogenetic System of Ephemeroptera. Springer.

[KS02] Kluge, N. Yu., & N. D. Sinitshenkova. 2002. Order Ephemerida Latreille, 1810. The true mayflies (=Ephemeroptera Hyatt et Arms, 1891 (s. l.); =Euephemeroptera Kluge, 2000. In: Rasnitsyn, A. P., & D. L. J. Quicke (eds) History of Insects pp. 89–97. Kluwer Academic Publishers: Dordrecht.

[KL01] Krzeminski, W., & C. Lombardo. 2001. New fossil Ephemeroptera and Coleoptera from the Ladinian (Middle Triassic) of Canton Ticino (Switzerland). Rivista Italiana di Paleontologia e Stratigrafia 107 (1): 69–78.

[K-P83] Kukalová-Peck, J. 1983. Origin of the insect wing and wing articulation from the arthropodan leg. Canadian Journal of Zoology 61: 1618–1669.

[M86] Marten, M. 1986. Drei für Deutschland neue und weitere, selten gefundene Eintagsfliegen aus der Fulda (Insecta, Ephemeroptera). Spixiana 9 (2): 169–173.

[M47] Mayr, E. 1947. Ecological factors in speciation. Evolution 1: 263–288.

[MH96] Miller, S. A., & J. P. Harley. 1996. Zoology 3rd ed. Wm. C. Brown Publishers: Dubuque (Iowa).

[PC91] Peters, W. L., & I. C. Campbell. 1991. Ephemeroptera (mayflies). In: CSIRO. The Insects of Australia: A textbook for students and research workers vol. 1 pp. 279–293. Melbourne University Press: Carlton (Victoria).

[R02] Rasnitsyn, A. P. 2002. Cohors Libelluliformes Laicharting, 1781 (=Subulicornes Latreille, 1807, =Hydropalaeoptera Rohdendorf, 1968). In: Rasnitsyn, A. P., & D. L. J. Quicke (eds) History of Insects pp. 85–89. Kluwer Academic Publishers: Dordrecht.

[RD77] Richards, O. W., & R. G. Davies. 1977. Imms’ General Textbook of Entomology 10th ed. vol. 2. Classification and Biology. Chapman and Hall: London.

[RJ93] Ross, A. J., & E. A. Jarzembowski. 1993. Arthropoda (Hexapoda; Insecta). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 363–426. Chapman & Hall: London.

[S02] Sinitshenkova, N. D. 2002. Ecological history of the aquatic insects. In: Rasnitsyn, A. P., & D. L. J. Quicke (eds) History of Insects pp. 388–426. Kluwer Academic Publishers: Dordrecht.

[SBG11] Staniczek, A. H., G. Bechly & R. J. Godunko. 2011. Coxoplectoptera, a new fossil order of Palaeoptera (Arthropoda: Insecta), with comments on the phylogeny of the stem group of mayflies (Ephemeroptera). Insect Systematics and Evolution 42: 101–138.

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