Rhyniognatha
Encyclopedia
Rhyniognatha hirsti is 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 ecosystem
s were being formed.
, 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 larva
l 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.
Ref Image: The University of Aberdeen
s - 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.
& 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.
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
. It emerged very early during the Early Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
Period, around 400 million years ago, when earth’s first terrestrial ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
s were being formed.
Evidence
The head part of a specimen, preserved in a fragment of Rhynie ChertRhynie chert
The Rhynie chert is an Early Devonian sedimentary deposit exhibiting extraordinary fossil detail or completeness . It is exposed near the village of Rhynie, Aberdeenshire, Scotland; a second unit, the Windyfield chert, is located some 700 m away...
, 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
Rhyniella praecursor
Rhyniella praecursor is a fossil springtail from the Rhynie chert formed during the Pragian stage of the Early Devonian; for some time it was believed to be the only hexapod from the Early Devonian...
, which is now known to be a springtail
Springtail
Springtails form the largest of the three lineages of modern hexapods that are no longer considered insects...
. Several other pieces, including the Rhyniognatha head, were also described as R. praecursor, stating the specimen to be a “supposed larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
l 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
Natural History Museum
The Natural History Museum is one of three large museums on Exhibition Road, South Kensington, London, England . Its main frontage is on Cromwell Road...
in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
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.
Ref Image: The University of Aberdeen
Food
Like other insects of its time, Rhyniognatha presumably fed on plant sporophyllSporophyll
A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls bear either megasporangia , or microsporangia...
s - which occur at the tips of branches and bear sporangia
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
, 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
EngelMichael S. Engel
Michael S. Engel is an American paleontologist and entomologist. He has undertaken field work in Central Asia, Asia Minor, and the Western Hemisphere, and published more than 300 papers in scientific journals. He was trained at the University of Kansas where in 1993 he received a B.S. in Cellular...
& Grimaldi
David Grimaldi
David A. Grimaldi 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 Entomology in 1986. Dr. Grimaldi is an authority in many fields of insect...
(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.
External links
- The University of Aberdeen Image of type specimen