October 18, 2012
Archaeologists Uncover Ancient Mayfly With Hitchhiker
Lee Rannals for redOrbit.com — Your Universe Online
Archaeologists have uncovered the oldest evidence of a hitchhiker from 16 million years ago, according to a study published in PLoS ONE.
Researchers said they found a mayfly trapped in ancient amber that had a hitchhiking springtail attached to it.
A springtail is a wingless arthropod that is among the most commonly found bugs all over the world.
The evidence is the first to show that springtails traveled on winged insects like mayflies. It is also just the second example of this mode of travel by springtails in the past or present.
Springtails are found in large numbers in soil all across the planet, and previous research suggests they may have spread through ocean current or by wind as part of aerial plankton. However, the latest discovery provides evidence of a new type of transportation.
The authors of the research paper said this is the first observation of an interaction between adult mayflies and any hitchhiking organism, and the first example of springtails hitching rides.
"This is a truly remarkable specimen. It highlights the potential for such fossils which provide snapshots of behaviors 'frozen in time' to provide clues to ecological associations occurring right under our noses today, but which may have gone unnoticed to date," David Penney from the University of Manchester and lead author of the study said in a statement.
The scientists said it appears as though the springtail attached itself for transport using its prehensile antenna.
They used a high resolution CT scanner to take over 3,000 X-rays of the fossil from different angles. The team then created slices, showing the fossil in cross sections. From these slices, 3D digital images of the springtail were made so they could make an accurate analysis of its behavior.
"The images are really impressive. This pioneering approach to studying fossils has allowed us an insight into the behavior of one of the world's most prevalent organisms," Penney said in a statement.
The 3D images show that the springtail's antenna is slightly detached from the mayfly, leading scientists to speculate the ancient hitchhiker may have been trying to escape as amber set around it.
"I was interested in the fact that this was the first time a creature had been found on an adult mayfly but I didn't truly appreciate the significance of my find until I used the CT scanner and was able to identify the animal as a springtail," Penney said in statement.
Adult mayflies live for just an hour or a few days, depending on the species, and the primary function of the adult stage is reproduction because they are unable to feed.
The amber specimen encasing the mayfly provides an accurate snapshot of behavior that scientists wouldn't be able to record normally.
The perfect condition of the mayfly demonstrates that it died instantaneously and wasn't moved far from where it rested when the resin ran over it.
"The CT scan allows us to build up a 3D image that catches minute details of the animal," Penney said. "We can rotate the image to see parts of the creature that are obscured when looking from the outside in. In effect, we are able to digitally dissect the fossil without causing any damage to it whatsoever. This technology has revolutionized how we study fossils and the findings are incredibly exciting."