''Rhyniognatha'' is an extinct genus of arthropod of disputed placement. It has been considered in some analyses as the oldest insect known, as well as possibly being a flying insect. ''Rhyniognatha'' is known from a partial head with preserved mouthparts from the Early Devonian aged Rhynie chert around 400 million years old, when Earth’s first terrestrial ecosystems were being formed. The type, and only species is ''R. hirsti'', which was named and described in 1928.R. J. Tillyard. 1928. Some remarks on the Devonian fossil insects from the Rhynie chert beds, Old Red Sandstone. ''Transactions of the Entomological Society of London'' 76:65-71 Other analyses have interpreted the specimen as a myriapod.

Evidence

Partial restorations of Rhyniognatha as myriapod

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, Samarendra Maulik and D.J. Scourfield. Hirst and Maulik published a report in 1926; in it they described ''

Rhyniella praecursor ''Rhyniella'' is a genus of fossil springtails (Collembola) from the Rhynie chert, which formed during the Pragian stage of the Early Devonian. One species has been described, ''Rhyniella praecursor''. For some time it was believed to be the only ...

'', 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. In 2004

Michael S. Engel Michael S. Engel, FLS, FRES (born September 24, 1971) is an American paleontologist and entomologist, notable for contributions to insect evolutionary biology and classification. In connection with his studies he has undertaken field expediti ...

and

David A. Grimaldi David A. Grimaldi (born September 22, 1957) is an entomologist and Curator of Invertebrate Zoology at the American Museum of Natural History in New York. He received his graduate training at Cornell University, where he earned his doctorate in ...

(2004) analyzed ''Rhyniognatha hirsti's''

mouthparts Mouthparts may refer to: * The parts of a mouth ** Arthropod mouthparts *** Insect mouthparts {{disambig ...

, and came to the conclusion that ''Rhyniognatha'' likely had wings, as they determined the mouthparts resembled those of a

mayfly Mayflies (also known as shadflies or fishflies in Canada and the upper Midwestern United States, as Canadian soldiers in the American Great Lakes region, and as up-winged flies in the United Kingdom) are aquatic insects belonging to the ord ...

, a flying insect. Nevertheless, a detailed reanalysis by Carolin Haug & Joachim T. Haug in 2017 came to a different interpretation, concluding that the identity of ''Rhyniognatha hirsti'' as a myriapod, specifically a

scutigeromorph The centipedes or Chilopoda are divided into the following orders. Scutigeromorpha The Scutigeromorpha are anamorphic, reaching 15 leg-bearing segments in length. Also known as house centipedes, they are very fast creatures, and able to withstan ...

centipede Centipedes (from New Latin , "hundred", and Latin , " foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', lip, and New Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, an ...

, was better supported by the available evidence, without being able to exclude an insect identity completely.

References

{{Taxonbar, from=Q1946495 Prehistoric insects of Europe Devonian insects Fossil taxa described in 1928 Fossils of Great Britain Transitional fossils Prehistoric insect genera Taxa named by Robert John Tillyard Controversial taxa