What in the world!?

[Mschmidt]

Do psammacora have sweepers? And how did the rock get so clean!?

Same spot 3 days ago

 

[tbrown]

You forgot the second picture?

Is that a Psamacorra or a Pavona/Lepto? My Mint Chip Pavona gets some nasty sweepers - almost 2" at times.

I'd say that looks like an urchin got a hold of that spot though...

 

[Mschmidt]

You're right...

It's a psammacora. Firework psammacora from tg to be specific.