The Cephalozygoptera, a new, extinct suborder of Odonata with new taxa from the early Eocene Okanagan Highlands, western North America

Abstract

We describe the Cephalozygoptera, a new, extinct suborder of Odonata, composed of the families Dysagrionidae and Sieblosiidae, previously assigned to the Zygoptera, and possibly the Whetwhetaksidae n. fam. The Cephalozygoptera is close to the Zygoptera, but differs most notably by distinctive head morphology. It includes 59 to 64 species in at least 19 genera and one genus-level parataxon. One species is known from the Early Cretaceous (Congqingia rhora Zhang), possibly three from the Paleocene, and the rest from the early Eocene through late Miocene. We describe new taxa from the Ypresian Okanagan Highlands of British Columbia, Canada and Washington, United States of America: 16 new species of Dysagrionidae of the existing genus Dysagrion (D. pruettae); the new genera Okanagrion (O. threadgillae, O. hobani, O. beardi, O. lochmum, O. angustum, O. dorrellae, O. liquetoalatum, O. worleyae, all new species); Okanopteryx (O. jeppesenorum, O. fraseri, O. macabeensis, all new species); Stenodiafanus (S. westersidei, new species); the new genus-level parataxon Dysagrionites (D. delinei new species, D. sp. A, D. sp. B, both new); and one new genus and species of the new family Whetwhetaksidae (Whetwhetaksa millerae).

The head of Cephalozygoptera (Odonata)

“…We of no force acting before or during diagenesis that might change the conservative zygopteran head shape to the diagnostic Cephalozygoptera shape. We conclude that the evidence from the specimens discussed by Nel & Zheng (2021), and those further examined and discussed here and by Archibald et al (2021) supports the proposal that the head shape ascribed to the Cephalozygoptera by Archibald et al (2021) is their actual shape, and that the Cephalozygoptera is a valid taxon.…”

“…The suborder is comprised of the extinct families Dysagrionidae and Sieblosiidae, both of which had been previously considered members of the Zygoptera or probably so, with various authors expressing reservations, suggesting that they might belong to an undefined, extinct suborder (e.g., Garrouste & Nel 2015). Archibald et al (2021) also erected the family Whetwhetaksidae, tentatively in the Cephalozygoptera. Nel & Zheng (2021) challenged the existence of the Cephalozygoptera, stating that its defining head morphology is an artefact, distorted from a zygopteran shape during fossilization.…”

Danowhetaksa gen. nov. with two species from the early Eocene Ølst Formation from Denmark, the first Palearctic Whetwhetaksidae (Odonata: Cephalozygoptera)

“…Remarks. We emend the diagnosis of Whetwhetaksidae of Archibald et al (2021) based on the fossils described here by the following: character state 1, pterostigma at least seven times as long as it is wide (this was ten times width in Archibald et al 2021), and remove character state 10, base to nodus percent wing length, as a synapomorphy for this group as this region is shorter in Danowhetaksa and does not now distinguish Whetwhetaksidae from Dysagrionidae or Sieblosiidae. Type and included species.…”

“…Recently, Archibald et al (2021) erected the extinct odonatan family Whetwhetaksidae for Whetwhetaksa millerae Archibald & Cannings of the Ypresian Okanagan Highlands of far-western North America, only a few million years younger than the Stolleklint clay. It is only known from wings, which are most like those of the extinct suborder Cephalozygoptera; however, the Cephalozygoptera is primarily diagnosed by head morphology (Archibald et al 2021) and so they assigned Whetwhetaksidae to it tentatively.…”

EcoDragons: A Game for Environmental Education and Public Outreach

“…First, the giant fossil dragonfly called Meganeura (the largest known dragonfly with about 70 cm of wingspan). Second, Cephalozygoptera is a recently discovered fossil suborder in the order Odonata [ 25 ]. Both cards allow the player to reintroduce two dragonfly cards, draw two cards of any kind, and play two cards at once.…”