These are the 'Dinochair' dinosaur office chairs available from Sichuan, China based MCSDINO Studio (of this cowboy riding on t-rex costume fame). The completely unadjustable fiberglass chairs measure 39" long, 39" high, 17" wide and are available in blue, pink, yellow (looks orange to me), and green. Unfortunately, they cost $934 apiece ($560 + $320 FedEx delivery + potential $54 import charge), and, I'm going to be honest: as much as I do love them, they look like they'd be more appropriate in a daycare setting than in front of a computer. I mean that can not be good for your back at all. Or ass. Or any part of you really. It's like they dropkicked ergonomics into a volcano and replaced them with a bunch of rapid-onset preexisting conditions. Plus, come on, how are you supposed to get any work done with the constant boner?
Keep going for a handful more shots and a video.
Thanks to Clem, who agrees these were almost certainly designed for some sort of quarter operated carousel at the mall and not computing.