The presumed oldest flying insect: more likely a myriapod?

PeerJ. 2017 May 30:5:e3402. doi: 10.7717/peerj.3402. eCollection 2017.

Abstract

The early fossil record of insects is scarce, with only few finds in the Devonian. All these finds appear problematic and controversial, partly due to incomplete preservation and challenging interpretation of many structures. We provide details of one of these important forms, Rhyniognatha hirsti from the famous Rhynie Chert Lagerstätte with up-to-date 3D imaging techniques. The fossil has been interpreted as the remains of one of the earliest flying insects. The specimen mainly preserves the remains of the head. The structures of the mandibles have been used as a main argument for an interpretation as an insect, but these are in fact less easy to interpret. New observed structures include the remains of a head capsule and an additional pair of mouth parts. Structures formerly suggested to represent remains of the head capsule or apodemes are more likely to be representing glands of ectodermal origin. The newly observed structures do not support an interpretation as an insect. Instead they make the interpretation as a myriapod more likely, possibly as a centipede. Centipede remains from the Rhynie Chert are known from scutigeromorphs. We therefore point out that R. hirsti could be interpreted as an early centipede.

Keywords: Chilopoda; Crussolum; Devonian insect; Rhynie chert; Rhyniognatha hirsti.

Grants and funding

This research received support from the SYNTHESYS Project (http://www.synthesys.info/) which is financed by European Community Research Infrastructure Action under the FP7 “Capacities” Program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.