Ancient sea worm leaves behind feces with evidence of Cambrian biodiversity

Ancient sea worm feces sheds light on a food web on the ocean floor.

Tyler MacDonald | Apr 03, 2018

A University of Kansas researcher has discovered details of a food web on the ocean floor through the 500-million-year-old poop of a primordial, predatory sea worm, according to The web once played a role in scattering bivalved arthropods, hyoliths, and tribolites.

"These are burrows of a wormlike animal where we have fossilized feces preserved," said University of Kansas researcher Julien Kimming. "This is rare because feces decompose very easilyit's not a very stable product fromanimals. These were preserved because thewormslived in burrows about 4 inches deep. They were hunting out of these burrows. We have something that acted very similar to a modern Bobbitt worm."

Kimming says that the worm that burrowed into the Mackenzie Mountain sediment could be an ancestor of modern Bobbitt Worms. In addition, it exhibits the evolutionary strategy of hunting from a burrow at the bottom of the sea, which has been successful for at least 500 million years.

"Bobbitt worms are big worms that live in the ocean today," Kimming said. "They prey on fish, live in burrows, have really big predatory appendages, and they hide in the burrow until a fish or other prey comes bythen they grab it, drag it into their burrow and eat it. There are several videos on YouTube about these guys, and it's fairly terrifying."

"Unfortunately, we don't have the worm itself preserved," he added. "But this was likely one of the biggest predators in its environmentthe animal was likely in the range of 6-12 inches with a diameter of three-quarters of an inch."