the root (no rank)
Eukaryota (domain)
Metazoa (kingdom)
Echinodermata (phylum)
Echinozoa (superclass)
Echinoidea (class)
Euechinoidea (subclass)
Echinoida (order)
[hide inferior taxa]
Echinidae (family)
Echinometridae (family)
Strongylocentrotidae (family)