Researchers at Simon Fraser University have found evidence that large predatory worms – some as long as two meters – roamed the ocean floor near Taiwan more than 20 million years ago. The finding, published today in the journal Scientific reports, is the result of restoring an unusual fossil trail that they identified as a hole in these ancient worms.
According to the study’s lead author, SFU Science Yu PhD student Yu-Yen Pan, fossil traces were found in a rocky area near coastal Taiwan. Fossil traces are part of a research area known as ichnology. “I was fascinated by this monstrous hole at first glance,” she says. “Compared to other fossil tracks, which are usually only a few tens of centimeters long, this one was huge; two meters long and two to three centimeters in diameter. The distinctive feather-like structures around the upper hole were also unique and none previously studied. the fossil has not shown similar characteristics. “
Pan and SFU Professor of Earth Sciences Shahin Dashgard are part of an international team that named the homes of these ancient giant worms Pennichnus beautiful!. Pan initiated the work while completing a master̵
After studying 319 specimens preserved in the early Miocene strata (22 million – 20 million years ago) in northeastern Taiwan, the morphological model of this fossil was built.
“Shahin encouraged us to turn to marine biologists, marine photographers and aquarium keepers to compare the holes to biological counterparts, which led us to conclude that this fossil was produced by giant, predatory worms in an ambush,” Pan said. .
The modern Bobbit worm, which is also large and predatory, is sometimes called a “sand attacker”, sensing its prey with its antennae, then grabs them with its powerful jaws and retreats into its burrow. When buried, his body occupies the entire hole, which explains the two-meter hole observed in Pennichnus.
Further analysis revealed a high concentration of iron around the upper hole, leading researchers to believe that the worm secretes mucus to strengthen and repair its hole wall after each meal.
The modern holes for Bobbit worm holes are similar to those of Pennichnus, suggesting that the sediment collapsed into the hole when withdrawing or pulling still-living prey under the seabed.
Marine predatory worms have existed since the early Paleozoic (> 400 million years ago), but their soft-tissue bodies decay, leaving little trace of their existence. Pennichnus formosae is thought to be the first known fossil record produced by an underwater planted predator, allowing researchers a rare opportunity to learn more about the behavior of this ancient sand attacker.
Materials provided by Simon Fraser University. Note: Content can be edited for style and length.