Rhizaria

A reader revisiting biology finds that the classic five- or six-kingdom model taught in schools has been replaced in modern systematics by six eukaryotic supergroups. Among them is Rhizaria, whose radiolarians — single-celled organisms with intricate mineral skeletons — are drawing amused comparisons to 'biblically accurate angels' because of their radial, ornate symmetry. The observation is sparking light conversation about how much classification of life has changed since many people last studied it.