Those would be one of the taller anubias varieties, I suppose. Can't see the leaves, so it's kinda hard to identify which one. Probably outgrew his tank.. and he cut off the tops.
Cheers. It's all that could be seen actually, I'm not that daft like! It was in a zoo, and the tank was 'in-wall' so couldn't see above the tank. Looks cool though eh? How long would it take to grow this big? I like the tree trunk effect the stems give