源 稿 窗
在文章中双击或划词查词典
字号 +
字号 -
折叠显示
全文显示
A scientist says fossils she collected from an ancient seabed in the mountains of northwestern Canada may be the earliest evidence of animal life on Earth ever discovered.
In a study published Wednesday in the science journal Nature, Laurentian University geologist Elizabeth Turner detailed how she found fossilized three-dimensional structures that resemble modern sponge skeletons in thin sections of rocks taken from the remnants of a prehistoric ocean reef.
Turner said the surrounding rock was 890 million years old, which would make the fossils she discovered about 350 million years older than the oldest undisputed sponge fossils previously found.
Many scientists believe Earth's first animal groups included simple, soft sponges or sponge-like creatures that lack muscles and nerves but have other features of simple animals, including cells with differentiated functions. But scientists often disagree on specifically what the earliest animal life might have looked like.
Turner's discovery will be carefully vetted by other scientists, and it has been greeted with excitement and skepticism.
Paleobiologist Graham Budd of Sweden's Uppsala University told The New York Times the problem was the 350 million-year gap between Turner's discovery and the next most recently discovered fossil. "It would be sensational. It would be like finding a computer chip in a 14th-century monastery," he said.
Turner herself told the Times she could be wrong. But other researchers said her study was important.
University of Southern California paleobiologist David Bottjer said he thought Turner had a pretty strong case. "I think this is very worthy of publishing - it puts the evidence out there for other people to consider," he said.
Some information in this report came from The Associated Press.