Children (14 direct children, 18 direct and indirect children):
Cryptolithus
(tree size 1)
Lace collar trilobite
Anebolithus
Bettonolithus
Trinucleus
(tree size 1)
Onnia
Onnia (trilobite)
Protolloydolithus
Microdiscus
Trinucleinae
Cryptolithinae
Marrolithinae
Tretaspidinae
Declivolithus
(tree size 1)
Costonia
(tree size 1)
Cryptolithoides