Researchers from the Swedish Museum of Natural History have discovered one of the most unusual species of sea snail in the world. These snails possess a hard shell made of iron that interlocks tightly, forming a robust armor covering their bodies and foot.
The newly discovered species was found at hydrothermal vents in the Indian Ocean. According to Anders Waren, the lead researcher who identified this strange snail, this “tiny monster” is the first known animal in the world with body parts made of iron sulfide. When he used iron tongs to examine the snail’s shell, it immediately stuck to the tongs. This led him to realize that the snail’s shell is made of iron and is magnetized. The research team suggests that the snail’s armor helps protect it from predators that inhabit the same vent. Even predatory snails that inject venom into their prey are at a disadvantage against these sturdy shells.
The research team utilized a remotely operated submarine to explore the hydrothermal vents in the Indian Ocean. Hydrothermal vents are underwater chimneys, often referred to as “black smokers” because they regularly spew out dark, hot water that can reach temperatures of 400°C. Despite the high temperature, the water does not boil due to the immense pressure at the ocean floor, which is 250 times greater than that at the surface. The water near the vents is cooler and rich in minerals (which gives it a black color), including components that contribute to the snail’s armor.
For modern animals, the body structure of this sea snail is indeed a bizarre “costume.” However, for many primitive creatures, especially those from the Cambrian period (540-500 million years ago), armor was “in fashion.” Genetic testing and anatomical studies indicate that these armored snails are closely related to modern snails. This may evoke images of a clunky Roman warrior clad in armor by the bustling Hoan Kiem Lake…
The composition of the snail’s shell contains two iron sulfide minerals: pyrite and greigite. Due to the typically unstable nature of sulfides, they are rarely seen on the bodies of organisms. However, iron and sulfur compounds are abundant in mineral-rich marine areas associated with hydrothermal ecosystems, which explains why these snails have sulfur iron shells.
Callum Roberts, a mollusk researcher at the University of York (UK), stated: “Hydrothermal vents are home to unique animal populations, helping us better understand the processes of evolution, adaptation, and the history of primitive life on Earth. This is a rich natural ecosystem that we must cherish and protect, just as we protect our national parks on land.”
