As for the rest of you invertebrates
Continue on your way!
Swarm the oceans!
Remember your trilobite forebears!
They brought you into this new world!
So they did.
The extinction gave new opportunities
To the animals.
New niches were opened.
Bryozoans formed forests as corals created reefs.
Brachiopods littered the seafloor.
Habitats opened up.
New creatures moved in.
Adaptive radiation brought new styles
To shelly animals.
A nice little bit of insurance from predators,
While Brachiopods articulated Conodonts made teeth out of bone.
Graptolites floated lazily by
Guiding fossil hunters to the Ordivician and Silurian.