This exhibit doesn't rotate. Its a mixed species habitat with all three primate species, not sure why you only saw the Titi Monkeys on your visit, that's odd, but I've seen all three species sharing this exhibit before.
@Neil chace Oh! I only saw the titis inside, and briefly saw a saki outside, so thought it rotated the three. I saw the tamarins, too, but they were too quick for me to get a photo of.
@TinoPup yeah, the tamarins have access to the large exhibit in the center (with the birds and sloths), however on multiple occasions I have seen them hanging onto the mesh of this habitat.
@Neil chace I didn't know about the tamarins so was a bit surprised to see them suddenly come running out from the ceiling! The went straight into the middle, becoming lost in the branches.
@TinoPup It's a shame you couldn't get a better look at them. I love it when zoos keep golden lion tamarins in habitats with access to natural light, as I find way too often zoos don't and they end up an off-white color. But when the tamarins get to show off their natural, bright gold color- such as at Roger Williams, it is a much better experience both for the guests and for the tamarins!