Preserved fossil eyes from Early Cambrian, discovered on Kangaroo Island in South Australia, have proven that primitive animals had excellent vision.
Dr. Jim Jago, a palaentologist at the University of South Australia and member of the team that has researched the fossil eyes, said they are over 500 million years old and look like squashed eyes from a recently swatted fly.
“These are by far the most complicated eyes known from this period of earth’s history. Each eye is seven to nine millimetres across and comprises over 3000 tiny lenses.
“As yet, the animal to which these eyes belonged is unknown, but they may have belonged to a large shrimp like animal. However, the rock layers in which the eyes are preserved include a dazzling array of fossil marine animals, many being new to science. They include primitive trilobite-like creatures, bizarre armoured worms and large swimming predators.”
The fossil compoundeyes have over 3,000lenses, giving themmuch sharper vision thananything previously found
from rocks this old
The finding was reported in the prestigious journal Nature in a paper titled ‘Modern optics in exceptionally preserved eyes of Early Cambrian arthropods from Australia’.
Dr. Jago says modern insects and crustaceans have ‘compound eyes’ comprising hundreds or even thousands of individual lenses. “They see their world as pixels, with more lenses meaning sharper vision,” he says.
“The fossil compound eyes have over 3,000 lenses, giving them much sharper vision than anything previously found from rocks this old. The eyes are much more complex than anything found previously in rocks of similar age. The newly discovered eyes are as advanced as the eyes in many living insects such as robberflies. The arrangement and size of the lenses indicates that these eyes belonged to an active predator that was capable of seeing in low light.”
The Nature paper reports these eyes provide evidence that the rapid development of advanced vision helped drive the Cambrian explosion of life that began around 540 million years ago, the time when most modern animal groups first appeared and proliferated in the oceans of the Earth. Given the tremendous adaptive advantage conferred by powerful eyes for avoiding predators and locating food and shelter, scientists report there must have been tremendous evolutionary pressure to elaborate and refine vision.
