This question is for science: How did trilobites become extinct?

Trilobites are a well-known fossil group of extinct marine arthropods that form the class trilobita. Trilobites first appear in the fossil record during the early cambrian period (540 million years ago) and flourished throughout the lower palezoic era before beginning a drawn-out decline to extinction when during the devonian all trilobite orders with the sole exception of proetida died out