A Silurian mystery - Final summing up
All of these possible answers are based on comparing what we can see in the rock with processes that we can observe affecting coral reefs today and our observations and understanding of the way the animals live and interact.
You can decide for yourself which you think is the most likely explanation of what you have observed.
Sadly, we'll never know the whole truth about what happened to these creatures 400 million years ago, but that's what makes palaeontology interesting!
One last question to think about; did everything which lived on or in the Wenlock Reef leave any evidence of itself?
Based on all the evidence and some good possible answers from detective work like you've done, palaeontologists have recreated the Wenlock Reef, complete with all its inhabitants, as they think it might have looked 400 million years ago. Take a look to find out more about the creatures and reef ecology.