If you heard of a giant worm that hides in the ground until it's time to pop up and capture its prey feeding on it while it's still alive, you would probably think it's from a horror movie. Yet, this kind of worm actually exists, and has for a long time, according to a new study published in the journal Scientific Reports.
"The feeding behavior of the giant ambush-predator “Bobbit worm” (Eunice aphroditois) is spectacular. They hide in their burrows until they explode upwards grabbing unsuspecting prey with a snap of their powerful jaws. The still-living prey are then pulled into the sediment for consumption," write eerily the authors of the study.
Why is this coming up now? Because the researchers discovered an ancient and possibly extinct ancestor of the worm that may just be even creepier than the current one.
This is quite an accomplishment since the bodies of predatory polychaetes consist mainly of soft tissue, making it difficult for them to be fossilized. The team stated that they used "morphological, sedimentological, and geochemical data from Miocene strata in northeast Taiwan" to identify this 20-million-year old worm.
More specifically, the researchers discovered the species' L-shaped burrows, which measured about 6.5 ft (2 mt) in length and about one inch (two to three centimeters) in diameter. The length of current-day specimens typically falls between 2 to 4 ft (60-120 cm), with some specimens growing up to 10 ft (3 mt).
They called their newly-discovered worm Pennichnus and explained how they studied 319 trace specimens preserved in sandstone sediments across Yehliu Geopark and Badouzi promontory in Taiwan in order to understand it. What they discovered was that the ancient worm had some distinct and rather unusual hunting and feeding habits.
"These data are compared to modern marine environments of the northwest Pacific and to biological analogs, and an argument is presented to suggest that the L-shaped burrows record the hunting behaviors of Miocene Bobbit worms," wrote the researchers.
"After each feed, the ambush-predatory polychaete re-establishes its burrow opening," further explained the researchers. Although the find is an exciting one for research, we are glad that these predatory giant worms are likely not in existence today.