The sandworms on the planet Arrakis are considered by many to be the real stars of the Dune novels of Frank Herbert. Reaching anywhere from 400 meters (1,300 ft) to a reported “half a league” (1.5 miles (2.4 km)) in length and 40 meters (130 ft) in diameter, they’re responsible for the treasured drug melange and featured in many action sequences because of their rideability and aversion to intruders.
Fortunately, these sandworms are fictional, but a smaller and equally vicious version does exist right here on Earth in the form of the Bobbitt worm (Eunice aphroditois) – a 10-foot-long bristle worm that burrows in the soft sediment of the ocean floor, waiting to ambush its prey by exploding out of the sand, grabbing their catch in vise jaws and dragging them back into the sediment for consumption. (Photos and videos here.) Fortunately, their favorite prey is fish and their larvae don’t excrete melange or any other spices. However, they don’t appear to have any natural enemies, which explains why they’ve lived nearly unchanged for 20 million years, according to a new study in the journal Scientific Reports.
“This trace fossil consists of an up to 2 m long, 2–3 cm in diameter, L-shaped burrow with distinct feather-like structures around the upper shaft. A comparison of Pennichnus to biological analogs strongly suggests that this new ichnogenus is associated with ambush-predatory worms that lived about 20 million years ago.”
Because they were squishy worms, no skeletal fossils of this species exist, but researchers led by National Taiwan University sedimentologist Ludvig Löwemark found trace fossils – burrows, prints and squiggles made by something on the floor of the ocean near Taiwan. By eliminating the traces being made by shrimp or snails – their burrows are longer and two-way – the researchers concluded they’d discovered the burrows of the ancestor of the modern Bobbitt worm.
We know what you’re dying to ask – yes, they’re named for Lorena Bobbitt, who in 1993 sliced off her sleeping husband’s penis after years of abuse. The nickname came from divers who witnessed the worms slicing fish in half with their jaws.
The 319 trace fossils discovered at two sites pointed to an ancient Bobbitt worm for a number of reasons. They were high in iron, which came from the mucous they used to stabilize the burrows. The tunnels were L-shaped, which is typical for soft worms that can’t dig too far down before hitting hard dirt and going horizontal. Finally, they look very much like the burrows of modern Bobbitt worms.
Despite not providing melange or being large enough to ride, Löwemark and his team plan to search for more trace fossils of the ancient worms, now that they know what to look for. They’ve named the trace fossils Pennichnus formosae, meaning “beautiful feather trace,” which refers to the feathery patterns left when the worm re-enters the burrow with its prey.
Ancient Bobbitt worm (Ubi vermis antiquis bobbitt) is far easier to remember.