I looks like it's dry rock in those pics. As long as it's not completely dried out, there might be some life deep inside, but the die-off from partial drying will cause a mini-cycle most likely.
+1 on surprises.
My tanks: 120 Reef w/L2 Algae Scrubber, 60 Reef Pond w/floating Algae Scrubber, 40 Breeder Reef w/L2 UAS Tester Algae Scrubber
I maintain: 144 SW Reef w/L2 Algae Scrubber | 200 SW Reef w/L4 Algae Scrubber
Special knowledge: Algae Scrubbers, Acrylic Fabrication