It is now found that Trilobites were egg layers just like their relatives, the horseshoe crabs, do now:

http://www.evolutionnews.org/2017/02/roe-roe-roe-never-before-seen-check-out-fossilized...

Comment: There are no known relatives preceding Trilobites. They simply appear in the fossil record, like all of the Cambrian Explosion animals. Great evidence for God.