Related how?

Biota (Life)
Eukaryote (Eukarya)
Podiata
Unikont (Unikonta)
Opisthokont (Opisthokonta)
Holozoa
Filozoa
Apoikozoa (Choanozoa)
Animal (Animalia)
Metazoa
Epitheliozoa
Eumetazoa
Bilateria
Deuterostome (Deuterostomia)
Echinodermata (Echinoderms)
Sea urchin (Echinoidea)
Euechinoidea
Irregularia
Neognathostomata
Pygaulidae

Trematopygus d'orbigny, 1857 (67882909)

Children (2 direct children, 2 direct and indirect children):

Trematopygus excentricus

Trematopygus novaki