The Mars Volta
The album includes guest appearances by Scott Kelly of Neurosis on "Crystal Skull", Josh Homme of Queens of the Stone Age on "Colony of Birchmen", as well as keyboard player Isaiah "Ikey" Owens of The Mars Volta and singer Cedric Bixler-Zavala of At the Drive-In and The Mars Volta on "Pendulous Skin" and "Siberian Divide", respectively.