June 30, 2011

Primitive Animals Had Excellent Vision

Paleontologists have discovered 515-million-year-old fossils which show that ancient animals had excellent vision and could even see in the dark, reports the Telegraph.

An international team of scientists led by the South Australian Museum and the University of Adelaide found the fossils, which look like "squashed eyes from a recently swatted fly," on Kangaroo Island in South Australia. Researchers said the eyes have more than 3,000 lenses, making them more powerful than any known eye fossil of a similar age.

The fossilized eyes were found in an isolated bed and it is not certain what animal they came from, but they probably belonged to a large shrimp-like creature, according to researchers. The rockbed containing the eyes also preserved a variety of ancient marine creatures, many new finds.

The lead author of the research, Associate Professor Michael Lee from the South Australian Museum and University of Adelaide's School of Earth & Environmental Sciences, said the owner of these eyes had a much better picture of the world around it, much better than the living horseshoe crab, which sees the world as 1,000 pixels. However, the eyes are not as good as the compound eyes of the modern dragonfly, which sees the world as 28,000 pixels.

Dr. Greg Edgecombe, a paleontologist at the Natural History Museum, said the eyes most likely belonged to a predator that must have been able to see in very low light conditions.

"This find is significant because it indicates that sharp vision like we see today in flies and lobsters must have evolved very rapidly. This would have happened soon after the first predators appeared during the evolutionary burst called the Cambrian Explosion around 540 million years ago," Edgecombe, who was involved in the research, told The Telegraph.

"These eyes would give animals a tremendous advantage as they were better adapted to avoid predators, and find food and shelter. Finding the Australian eyes allows us to date the origin of sophisticated vision," he added.

The study is published today in the journal Nature.


Image 1: The compound eyes of a living insect -- a predatory robber fly -- showing the individual lenses. Credit: Photo by Peter Hudson (South Australian Museum)

Image 2: A half-billion-year-old fossil compound eye, showing exquisite detail of the visual surface (the individual lenses can be seen as darker spots). Credit: Photo by John Paterson (University of New England)


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