This is the shell of the *diploria labyrinthiformis*, a species of the Mussidae and Merulinidae family, and also known commonly as the brain coral found in the western Atlantic Ocean and Caribbean Sea. Its deep, interconnected double valley patterns is what gives it the brain-like quality.
More info here: https://en.wikipedia.org/wiki/Brain_coral
ID number: 339.12
Captured with Artec Spider 3D Scanner https://www.artec3d.com/portable-3d-scanners/artec-spider-v2