I wonder if there are data available considering the longevity (maximum individual age) of cidaroid sea urchins? Both, data from free-living as well as from captive urchins are welcome!
Although not answering your question directly have you seen the following paper, the link is also included:
Bodnar, A.G., Coffman, J.A., 2016. Maintenance of somatic tissue regeneration with age in short- and long-lived species of sea urchins. Aging Cell 15, 778–787. doi:10.1111/acel.12487