Level 1 - Absolute Beginner
Scientists looked again at a very old fossil. It is a small head of an animal. It is about 408 million years old.
For many years, people thought it was the oldest flying insect. The new scan says: we are not sure.
If it is not an insect, then insects may have learned to fly much later. Science changes when we look closer.
- fossil
- the old remains of a living thing in rock
- insect
- a small animal with six legs
- fly
- to move through the air with wings
- scan
- to look at something with a machine
- old
- having lived or existed for a long time
- head
- the top part of a body
- scientist
- a person who studies nature
- later
- after the present time or another time
Level 2 - Elementary
A fossil called Rhyniognatha hirsti is about 408 million years old. It is only a head, but it has been very famous. In 2004, two scientists said its jaws looked like the jaws of insects that can fly. That meant flying insects lived at least 400 million years ago.
Not everyone agreed. In 2017 other scientists said the head might belong to a myriapod, an animal like a centipede. Now a new study in the journal Scientific Reports has scanned the fossil again with a strong microscope method called confocal microscopy.
The result: the identity of the fossil is still not settled. Because of this, the study says the story of when insects first learned to fly may need to change. One headline says flight could have begun up to 80 million years later.
- jaw
- the bone that holds the teeth and opens the mouth
- myriapod
- an animal with many legs, like a centipede
- microscope
- a tool that makes small things look big
- identity
- who or what something is
- agree
- to have the same opinion
- famous
- known by many people
- settled
- decided and finished
- headline
- the title of a news story
Level 3 - Intermediate
A fossil head about 408 million years old has again become the centre of a debate about when insects took to the air. The specimen, Rhyniognatha hirsti, has sat in London's Natural History Museum since the 1920s. In 2004, researchers Michael Engel and David Grimaldi argued in Nature that its double hinged jaws resembled those of modern winged insects, which pushed the origin of flying insects back to at least 400 million years ago.
The claim never went unchallenged. In 2017 Joachim and Carolin Haug argued in PeerJ that newly observed structures made a myriapod, possibly a centipede, more likely than an insect. Now a study in Scientific Reports has re-examined the fossil with confocal microscopy, a technique that builds detailed images from sharply focused layers of light. According to a summary of the paper, the scans left the animal's identity unresolved.
That uncertainty matters because the old date rested on a single fragment. If the head is not clearly an insect, the earliest secure evidence for flying insects moves later in time. The paper's headline suggests the origin of insect flight could be up to 80 million years later than the Rhyniognatha claim implied, and shows how much a famous conclusion can depend on one specimen.
- specimen
- a single example of a plant or animal used for study
- debate
- a discussion in which people disagree
- resemble
- to look like
- unchallenged
- not questioned
- technique
- a method for doing something
- unresolved
- not yet explained or decided
- fragment
- a small broken part
- implied
- suggested without being said directly
Level 4 - Advanced
Few fossils carry as much argumentative weight per gram as the fragment known as Rhyniognatha hirsti. Roughly 408 million years old and preserved only as a head, it has been cited since 2004, when Michael Engel and David Grimaldi reported in Nature that its double hinged mandibles matched those of winged insects, as evidence that flight evolved at least 400 million years ago. The specimen, held in London's Natural History Museum since the 1920s, thus anchored a whole timeline.
Yet the anchor was always contested. In 2017 Joachim and Carolin Haug argued in PeerJ that newly visible structures favoured a myriapod, perhaps a centipede, over an insect. A new paper in Scientific Reports now brings confocal microscopy, which assembles detailed images from sharply focused optical sections, to the question. By the account of its summary, the scans leave the identity of the animal unresolved, which undermines the use of the fossil as proof of early flight.
The implications are considerable. Palaeontologists date the emergence of wings from the oldest unambiguous fossils, and if this specimen can no longer be counted, the earliest secure evidence shifts later. The paper's title suggests insect flight could have originated up to 80 million years after the date the head once implied. The episode illustrates a recurring lesson in evolutionary science: a bold inference from a single, fragmentary specimen is a hypothesis awaiting better data, and better instruments can retire it as easily as confirm it.
- argumentative
- relating to reasoning used to support a claim
- mandible
- the jaw of an insect or other arthropod
- anchor
- to fix firmly in place; something that holds a structure steady
- contested
- disputed or argued about
- optical
- relating to light or vision
- undermine
- to weaken gradually
- unambiguous
- having only one possible meaning
- fragmentary
- made of incomplete pieces
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