Kampecaris obanensis: Paleontologists Find World’s Oldest Fossil Bug
A 425-million-year-old fossil millipede from Scotland is the oldest-known ‘bug’ (an insect, arachnid or other related creature), according to new research published in the journal Historical Biology.
Named Kampecaris obanensis, the prehistoric millipede lived during the Silurian period, about 425 million years ago.
The ancient creature was a small (2-3 cm in length), short-bodied animal with three recognizable sections.
It likely lived near a lake in a semi-arid forested environment and ate decomposing plants.
Its fossilized remains were unearthed on the island of Kerrera in the Scottish Inner Hebrides.
The specimen is about 75 million years younger than the age other paleontologists have estimated the oldest millipede to be using a technique known as molecular clock dating.
The oldest fossil of a land-dwelling, stemmed plant, Cooksonia, has the same age as Kampecaris obanensis and is also from Scotland.
“Although it’s certainly possible there are older fossils of both bugs and plants, the fact they haven’t been found — even in deposits known for preserving delicate fossils from this era — could indicate that the ancient millipede and plant fossils that have already been discovered are the oldest specimens,” said Dr. Michael Brookfield, a researcher in the Department of Geological Sciences at the Jackson School of Geosciences at the University of Texas at Austin and the University of Massachusetts Boston.
If that’s the case, it also means both bugs and plants evolved much more rapidly than the timeline indicated by the molecular clock.
Bountiful bug deposits have been dated to just 20 million years later than the fossils.
And by 40 million years later, there’s evidence of thriving forest communities filled with spiders, insects and tall trees.
“Who is right, us or them? We’re setting up testable hypotheses — and this is where we are at in the research right now,” said Dr. Elizabeth Catlos, also from the Department of Geological Sciences at the Jackson School of Geosciences at the University of Texas at Austin.
“It’s a big jump from these tiny guys to very complex forest communities, and in the scheme of things, it didn’t take that long,” Dr. Brookfield said.
“It seems to be a rapid radiation of evolution from these mountain valleys, down to the lowlands, and then worldwide after that.”
M.E. Brookfield et al. Myriapod divergence times differ between molecular clock and fossil evidence: U/Pb zircon ages of the earliest fossil millipede-bearing sediments and their significance. Historical Biology, published online May 13, 2020; doi: 10.1080/08912963.2020.1761351