ARMIDALE, AUSTRALIA — Most of us can look at a rock fossil like this and not see much, but scientists have looked and concluded that these long-gone sea animals had night vision eyes that sparked a prehistoric arms race.
Here's the details: Radiodonta, meaning "radiating teeth", are a group of arthropods that dominated the oceans around 500 million years ago.
The many species share a similar body layout resembling elongated prawns with cone-shaped teeth arranged in a circle around the mouth.
Scientists led by Dr John Paterson published a new study in the journal Science Advances, claiming they have now found that radiodonta developed sophisticated eyes over 500 million years ago, with some specially adapted to the dim light of deep water.
The study focused on fossils from Emu Bay Shale on Kangaroo Island, in South Australia.
The scientists explain that these fossils are unique because it's the only place where the visual surface of the eye is preserved.
In other sites in China, Canada, the USA and elsewhere, only the outline of the eyes is known but there's no information on their lenses.
One eye sample had a jaw-dropping 28,000 lenses — a number only rivalled by insects like the dragonfly.
Dr. Paterson added: "not only did they possess sharp vision, but they were capable of seeing at different light levels within the ocean."