Hardouinia

Hardouinia — Bo‘r davrida yashagan, yo‘qolib ketgan echinoidlar (dengiz kirpilar) urug‘i hisoblanadi. Uning qoldiqlari Shimoliy Amerika hududida topilgan.

 Manbalar 

 Fossils (Smithsonian Handbooks) by David Ward (Page 182)

 Havolalar  
Hardouinia in the Paleobiology Database