Scientists for the first time have uncovered an underworld of animal life thriving beneath the seafloor.

An expedition to a volcanically active ridge in the Pacific off South America has revealed worms, snails, giant tubeworms and other strange creatures lurking below steamy underwater hot springs.

Researchers have long studied animal communities near such hydrothermal vents. Many thought only microbes and viruses could survive underneath. To their surprise, an underwater robot last summer overturned volcanic slabs and found diverse life under the vents.

“This was totally unexpected,” said study co-author Sabine Gollner with the Royal Netherlands Institute for Sea Research.

Young critters from above the seafloor could be traveling through the vents to settle in the depths, Gollner said.

The research published Tuesday in the journal Nature Communications.

Future studies will help reveal whether colonies of animal life exist below other hydrothermal vents around the globe.

“This is an initial discovery that’s really promising,” said Jason Sylvan, a microbiologist at Texas A&M University who was not involved with the research.

(AP)