Is something eating my Euphyllia skeleton?

[AquaScott]

I just noticed this morning, though this may have been going for a bit. The skeleton was more robust and in tact a few weeks ago. I'm not sure if it's degeneration, or if something is eating it. I have seen my urchin hanging out on the Euphyllias lately, but didn't think anything of it. Would an urchin do it?

 

[Flippers4pups]

Urchin could do that.

 

[AquaScott]

Yep. It was the urchin. I loved the urchin, but it loved my euphyllia and all the coralline algae. It was a hitchhiker and I was super excited the first time I saw it in the tank.