Dodatak:Abecedni popis trilobita: I
Ib uredi
Ibexaspis,
Id uredi
Idahoiidae, Idiorapha,
Ig uredi
Igarkiella, Iglesiella, Ignotogregatus,
Ij uredi
†Ijacephalus Ogienko, 1974 uredi
Trilobita → Ptychopariida → Acrocephalitidae
†Iyouella Geyer and Palmer 1995 uredi
- †Iyouella contracta Geyer & Palmer 1995
Trilobita → Redlichiida → Holmiidae
Il uredi
Illaenacea Illaenidae, Illaenina, Illaeninae, Illaenoides, Illaenula, Illaenuridae, Illaenurus, Illaenus,
In uredi
Iniospheniscus, Iniotoma, Inouyina, Inoyellaspis, Interalia,
Io uredi
Iohomia, Iolgia,
Ir uredi
Iranaspis,
†Irgitkhemia Chernysheva 1977 uredi
Animalia → Arthropoda → Trilobita → Redlichiida Irinia, Irvingelloides,
Is uredi
Isabelinia,
†Isbergia Warburg 1925 uredi
- †Isbergia planifrons Warburg 1925
Trilobita → Proetida → Aulacopleuroidea → Rorringtoniidae → Rorringtoniinae Ishpella, Isocolidae, Isotelinae, Isoteloides, Isotelus, Issafenia, Issafeniella, Isyrakopeltis,
It uredi
Itagnostus, Ityophoridae, Ityophorus,
Iv uredi
Iveria,
Iw uredi
Iwayaspis,
Iy uredi
†Iyouella Geyer and Palmer 1995 uredi
- †Iyouella contracta Geyer & Palmer 1995