Prehistoric worms have been carrying sea beds for 500 million years. Active life was an unpredictable environment, a study by the University of Saskatchewan (USASC).
In the Cambrian period, the deep ocean sea bed thought it could be dangerous for livestock, because it did not have enough oxygen.
But the research published in the scientific journal Geology The existence of citrus fossil tunnels shows the evolution of dinosaurs 270 million years before Cambrian.
The discovery, by USAST professor Brian Pratt, suggests that at that time animal life was thought to be more sedate.
The worms-worms lived through sediments and staggered where the heads are invisible to the eye. But Pratt had "had a hunch" and cut off rocks and scan to see the old life signs appear.
Rocks were one of the remote areas of Mackenzie in the northwestern Canadian territories, Pratt found 35 years ago.
Pratt then digitized better image surfaces to be closely analyzed. Then, they made a series of different types of rocky terrain and types of "superhighway" burrows.
They were just a few millimeters, and others were big fingers. They were reduced to sculpting simple polykety or bite, but one of the major forms was a prey to attack worms and worms.
Pratt said the unexpected discovery was "shocked".
"For the first time, we demonstrated the large worm populations that live in the sediment, that is, it was similar," he said. "There are carved stone worms -buyers- who have been in the ground for 50 million years, and other animals once again thought that anyone was rebuilt or bioturbating."
Pratt, geologist and paleontologist and the Fellow of the American Geological Society discovered the sedimentary rocks like Burgess Shale in the tunnels, the Rocky Canadian rocky fossil tank.
The discovery regains the oxygen level in the old oceans and on the continental shelves.
During the Cambrian period, there was an explosion of life on the ground in the oceans and the development of multicellular organisms, prehistoric worms, clams, snails and crabs and lobster ancestors. Previously, the sea isolated microbial bacteria and algae.
It has always been that Burgess Shale has preserved well-known beings all over the fossil's wealth, since there was no lack of oxygen in the seabed, and animals did not live in the mud.
Prat's discovery, along with co-author Julien Kimmig of the University of Kansas, was keeping enough oxygen in several seabed beds.
"Serendipity is a common aspect of my type of research," said Pratt. "These unusual rocks were found in recent years. I prepared a series of samples in a hunch and I improved the images as I was really surprised," he said.
"This has to be investigated, not just in Cambrian Shales, but also in the smallest rocks. People should demonstrate the same techniques that show signs of life of the sample."
She eats old marine worm, poisons and leaves behind the evidence of Cambrian biodiversity