Media Release
June 30 2011
Primitive creatures had powerful eyes
South
Australian and international scientists have discovered that some
ancient, primitive animals had excellent vision. The discovery has been
revealed today in the prestigious journal
Nature.
UniSA palaeontologist
Dr Jim Jago, who was part of the research team, says evidence comes
from Kangaroo Island fossils. He says the fossils, which are over 500
million years old, look like squashed eyes from a recently swatted fly.
“Our Nature paper reports extremely well preserved fossil eyes from
Early Cambrian (approximately 515 million years old) rocks from Emu Bay
on Kangaroo Island,” Dr Jago says.
“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 Nature paper is titled: ‘Modern optics in exceptionally preserved
eyes of Early Cambrian arthropods from Australia’. Authors are Dr
Michael Lee from the SA Museum and University of Adelaide, Dr Jago, Dr
Jim Gehling from SA Museum, Dr John Paterson from the University of New
England, Dr Diego Garcia-Bellido from Madrid and Dr Greg Edgecome from
the Natural History Museum in London.
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 3000 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, there must
have been tremendous evolutionary pressure to elaborate and refine
vision, the scientists report.
Contact for interview
- Dr Jim Jago office (08) 8302 3113 email jim.jago@unisa.edu.au
Media contact
- Kelly Stone office (08) 8302 0963 mobile 0417 861 832 email kelly.stone@unisa.edu.au