Out of the destruction of trench warfare in World War I, geoscientists are getting a rare glimpse of into the life and behavior of 425-million-year-old marine life.

An international team of scientists has found a treasure trove of rare fossils within the WWI trenches dug between Italy and Austria in the Alps. Within the iron oxide and limestone formation, they discovered the fossilized remains of crinoids, a prehistoric grandfather of the sea lilies, thought to date back 425 million years. Their study was published in the open-access journal Geologica Acta.

Crinoids look a little bit like an underwater flower, with a long stem and a feathered head that was used to catch plankton for food. The 600 extant species of these marine animals pretty much ruled the ocean bed at one time. You can find limestone beds from the Paleozoic era in North America and Europe almost entirely made up of their fragments. Although they aren’t nearly as abundant as they once were, you can still find many in the world’s oceans.

Despite how common crinoids were, the researchers say these fossils are particularly rare as they are of juveniles. Even stranger for crinoids, they weren’t attached to any rock when they were discovered.

A modern-day crinoid clings to a shallow reef in Indonesia. Ethan Daniels/Shutterstock

The nature of these fossils leads the researchers to believe that ancient crinoids had an interesting way of getting around. Before they reached reproductive age, they clung onto a moving sea-faring object to transport them through the ocean. The researchers think they could have even been attached to an animal such as cephalopod.

“The fossils indicate that they were either attached to objects floating in the water at the time, or attached to another bottom dweller that lacked preservable hard parts," co-author William Ausich, professor of earth sciences at Ohio State University, said in a statement. "We now have important information about the behavior of these ancient organisms, and a clue as to why they had such a wide geographic distribution.”

After all, if their crinoid ancestors spent their entire life anchored to one rock, they couldn't have taken over the oceans so effectively.

Microscope images of the juvenile crinoid fossils discovered in the Alps. A Ferretti et al/GeologicaActa