The wing venation of the Protomyrmeleontidae (Insecta: Odonatoptera) reconsidered thanks to a new specimen from Molteno (Triassic; South Africa)

ABSTRACT

Wing venation homologies of the Protomyrmeleontidae, a widespread group of damselfly-like stem-Odonata during the Triassic, are debated. The two main interpretations essentially disagree on the identification of RP branches. Indeed, Protomyrmeleontidae display a very complex wing venation necessarily involving, in a way or another, fusions of the concave RP branches with the convex intercalary veins. As a consequence, vein elevations in the radial area are challenging to interpret. Here, we present a new Triassic specimen from the Molteno Formation (Karoo Basin, South Africa), Moltenagrion koningskroonensis gen. et sp. nov. It displays a unique venation pattern supporting a new, alternative interpretation involving a pair of supplementary intercalaries. The systematic implications of this wing venation interpretation are then discussed. The new species is assigned to the new family Moltenagrionidae fam. nov., itself considered sister-group of the family Protomyrmeleontidae, as previously delimited, both composing the super-family Protomyrmeleontoidea. Diagnoses of these taxa are revised according to our new interpretation.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:6AF81E13-E57B-4EF8-BBBB-5392EF439E87

KEYWORDS:

• Molteno Formation
• Triassic
• wing venation
• Protomyrmeleontidae
• stem-Odonata

Acknowledgments

Data on the ‘Anderson collection’ and the new fossil species in particular were collected during two visits at the Evolutionary Studies Institute (School of Geosciences, University of the Witwatersrand; Johannesburg, South Africa; 2014, 2015). We are grateful to M. Bamford and T. Scott-Turner who proved very helpful during these visits. Visits was supported by two grants from the ‘Action Transversale Muséum Emergences’ (O. Béthoux, 2014, 2015) and by a grant from the DFG (WA 1492/12-1; T. Wappler and O. Béthoux, 2014). We are grateful to the Andersons for their dedication towards collecting fossil insects from the Molteno Formation. We are grateful to R. Garisson for the loan of wings of extant species that were photographed to compute RTI files and also to P. Smith for sending us picture of the specimen of Triassagrion. This work is part of the first author’s PhD project funded by ‘Sorbonne Universités’. Finally, we are grateful to two anonymous reviewers for constructive comments.

Disclosure statement

No potential conflict of interest was reported by the authors.