Purple sea urchins (Strongylocentrotus purpuratus), believe it or not, are actually closely related to humans as revealed by genomic sequencing.  Sea urchins, in general, have a range of lifespans, and purple sea urchins have one of the highest with a maximum of more than 50 years!  This makes sea urchins relevant for a variety of aging research.  

Sketch and fact contributed by Maggie Creamer

Source: Bodnar, A. G. (2015). Cellular and molecular mechanisms of negligible senescence: insight from the sea urchin. Invertebrate Reproduction & Development, 59(sup1), 23-27. DOI: 10.1080/07924259.2014.938195