The Diadematidae are a family of sea urchins. Their tests are either rigid or flexible and their spines are long and hollow. \n* Astropyga (Gray, 1825) \n* Astropyga radiata (Leske, 1778), extant \n* Astropyga pulvinata (Lamarck, 1816), extant \n* Astropyga magnifica (Clark, 1934), extant \n* Centrostephanus (Peters, 1855) \n* Centrostephanus asteriscus (Agassiz & Clark, 1907), extant \n* Centrostephanus coronatus (Verrill, 1867), extant \n* Centrostephanus fragile (Wiltshire in Wright, 1882), Santonian, Maastrichtian, Danian \n* Centrostephanus longispinus (Philippi, 1845), extant \n* Centrostephanus nitidus (Koehler, 1927), extant \n* Centrostephanus rodgersii (Agassiz, 1863), extant \n* Chaetodiadema (Mortensen, 1903) \n* Chaetodiadema granulatum (Mortensen, 1903), extant \n* Chaetodiadema keiense (