Genus
Porterfieldia Cooper, 1953
List of species
1. Porterfieldia humilis Hadding, 1913 | Ordovician
Luokittelu
| Organism group | Biota |
| Kingdom | Animalia |
| Phylum | Arthropoda |
| Subphylum | Trilobita |
| Order | Ptychopariida |
| Suborder | Olenina |
| Family | Olenidae |
| Superfamily | Triarthrinae |
| Genus | Porterfieldia |
| Species | humilis |
| Genus | Triarthrus |