A well-preserved set of appendages of Olenoides serratus from the Burgess Shale, one of the two trilobite species analysed in the recent study. You can see the delicate spines on the trilobite's pair of opposing limbs. Image by Sarah Losso
The Science News column from the Natural History Museum in London has a story about trilobites. A new paper by Dr. Greg Edgecombe, a researcher at the museum who focuses on the evolutionary history of arthropods, about how some trilobites fed was published in the Royal Society B. Instead of teeth, it appears that these trilobites used their legs to crush and shred their prey before passing the food to their mouths.
By studying modern horseshoe crabs, researchers have been able to build up a picture of how some extinct arthropods such as trilobites may have fed on hard-shelled prey.
Some trilobites probably used their legs to crush their prey before passing the food to their mouths.
Trilobites are arthropods that lived on Earth between 521 to 252 million years ago. To date there are more than 20,000 species recorded, making them one of the most successful groups of early arthropods to have evolved. Despite leaving a vast fossil record, very little is known about how they may have eaten.
It turns out that just like we use chopsticks to move food towards our mouth, some trilobites may have stabbed and crushed their prey with their legs as they ate.
'We used the horseshoe crab, a living arthropod that eats hard prey, to bring life to models of how two species of trilobite used their legs when feeding,' says Greg.
The researchers found that one trilobite species, Redlichia rex, shows a similar leg structure and pattern of strain at its leg base as the horseshoe crab, indicating it used its legs to crush shelled creatures before eating them, a behaviour called durophagy.
This feeding behaviour may have accelerated the 'arms race' between trilobite predators and their shelled prey.
