the root (no rank)
Eukaryota (domain)
Metazoa (kingdom)
Arthropoda (phylum)
Chelicerata (class)
Merostomata (subclass)
Xiphosura (order)
Limulidae (family)
Limulus (genus)
[hide inferior taxa]
Limulus polyphemus (species)
Limulus sp. (species)