Era
Cretaceous
179
Tertiary
124
Precambrian
75
Paleozoic
70
Permian
62
Eocene
61
Pennsylvanian
60
Devonian
58
Ordovician
58
Mississippian
57
Cenozoic
54
Miocene
54
Quaternary
45
Pleistocene
43
Triassic
43
Jurassic
41
Mesozoic
38
Proterozoic
38
Pliocene
27
Cambrian
26
Oligocene
25
Silurian
20
Carboniferous
18
Holocene
17
Archaean
15
Paleocene
15
Neogene
14
Paleogene
5
1864-1945
2
1805-1885
1
1809-1865
1
1938-
1
Dovanian
1