Rhyniognatha

Rhyniognatha Temporal range: 400 Ma PreЄ Є O S D C P T J K Pg N ↓ Early Devonian
A hypothetical evolutionary pathway leading to the wings believed to be present on Rhyniognatha and its descendants.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Genus:	†Rhyniognatha Tillyard, 1928
Species:	†R. hirsti
Binomial name
†Rhyniognatha hirsti Tillyard, 1928
Synonyms
Rhyniella praecursor (partim)

Rhyniognatha hirsti is often considered the world’s oldest known insect. It emerged very early during the Early Devonian Period, around 400 million years ago, when Earth’s first terrestrial ecosystems were being formed.

Evidence

The head part of a specimen, preserved in a fragment of Rhynie Chert, was collected in 1919 by the Reverend W. Cran, who provided it to S. Hirst, S. Maulik and D.J. Scourfield. Hirst and Maulik published a report in 1926; in it they described Rhyniella praecursor, which is now known to be a springtail. Several other pieces, including the Rhyniognatha head, were also described as R. praecursor, stating the specimen to be a “supposed larval insect”. The specimen was correctly identified as a different species and renamed Rhyniognatha hirsti in 1928 by entomologist Robin J. Tillyard. It was later donated by D.J. Scourfield to the Natural History Museum in London where it is currently displayed on a microscope slide. Scientists have not found much information, but due to the shape of the jaws they think it was probably winged. Nevertheless, some authors have interpreted Rhyniognatha hirsti rather as a myriapod.

Ref Image: The University of Aberdeen

Food

Like other insects of its time, Rhyniognatha presumably fed on plant sporophylls - which occur at the tips of branches and bear sporangia, the spore-producing organs. The insect’s anatomy might also give clues as to what it ate. The creature had large mandibles which may or may not have been used for hunting.

Wings

Engel & Grimaldi (2004) show that R. hirsti was relatively derived within early insects, sharing many characteristics with winged insects. This could mean that R. hirsti itself was already winged.^[1]

Footnotes

References

• Andrew Ross. "The oldest fossil insect in the world". Natural History Museum. 
• Michael S. Engel & David A. Grimaldi (2004). "New light shed on the oldest insect". Nature. 427 (6975): 627–630. PMID 14961119. doi:10.1038/nature02291. 
• Carolin Haug & Joachim Haug (2017). "The presumed oldest flying insect: more likely a myriapod?". PeerJ. 5: e3402. doi:10.7717/peerj.3402. 

External links

• Paul Rincon (2004-02-11). "Oldest insect delights experts". BBC News. 
• The University of Aberdeen Image of type specimen