Era
Ordovician
Ordovicien
173
From 425 to 500 million years ago
141
Cambrian
102
Silurian
73
From 425 to 570 million years ago
26
Cambrien
23
Devonian
17
From 405 to 500 million years ago
14
Silurien
13
Precambrian
6
Mississippian
5
Cretaceous
4
Dévonien
4
Triassic
4
From 345 to 500 million years ago
3
Paleozoic
3
Carboniferous
2
From 190 to 500 million years ago
2
From 310 to 500 million years ago
2
From 425 million to 5 billion years ago
2
From 65 to 500 million years ago
2
Mississippien
2
Pennsylvanian
2
Précambrien
2
Trias
2
1982
1
Cenozoic
1
Cénozoïque
1
Crétacé
1
Mesozoic
1
Mésozoïque
1
Miocene
1
Ordovocian
1
Paléozoïque inférieur
1
Paléozoïque
1
Tellico-Sevier Belt
1