Researchers Discovered Lair of an Ambush-Predatory Worm from 20 Million Years Ago
- Eunicid polychaetes have long, segmented bodies, and strong denticulated jaws.
- They are widely distributed in tropical to temperate shallow marine to shores.
- The “Bobbit worm” is one of the largest eunicids that fascinated the public.
- Burrowing “Bobbit worm” only extend a minor portion of their body outside of the sediment, thus observations on their behavior beneath the seafloor are difficult.
- However, the feeding behavior of this giant ambush-predator is amazing.
- “Bobbit worm” hides in burrow and explodes upwards snatching unsuspecting preys with their powerful jaws.
- The preys are still alive when the “Bobbit worm” pulls them into the sediment for consumption.
- Ancient predatory polychaetes have soft-tissue bodies resulting in an incomplete fossil record.
- Nothing is known about the burrows and behavior beneath the seafloor of these ancient polychaetes.
- Researchers used data from Miocene strata in northeast Taiwan to erect a new ichnogenus, Pennichnus.
- Ichnogenus is a group of trace fossils that is given a name because the similarity of the traces suggests they were made by closely related species of organisms.[1]
- Fossil length: 2 meters long
- Fossil diameter: 2 to 3 centimeter
- Fossil shape: L-shaped burrow
- The fossil has distinct feather-like structures around the upper shaft.
- A comparison of Pennichnus to other biologically similar organisms strongly suggests that this new ichnogenus is related with ambush-predatory worms that lived about 20 million years ago.
Related Research: Smelling Danger – Alarm Cue Responses in the Polychaete Nereis (Hediste) diversicolor (Müller, 1776) to Potential Fish Predation
Sources:
Pan, YY., Nara, M., Löwemark, L. et al. The 20-million-year old lair of an ambush-predatory worm preserved in northeast Taiwan. Sci Rep 11, 1174 (2021). https://doi.org/10.1038/s41598-020-79311-0
[1] https://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/ichnogenus
Related External Link: Ambush predator – Wikipedia
