Era
Cretaceous
317
Precambrian
192
Tertiary
175
Quaternary
161
20th century
140
Cenozoic
139
Paleozoic
135
Permian
119
Mesozoic
113
Pennsylvanian
113
19th century
101
Eocene
98
Pleistocene
94
Miocene
87
Jurassic
86
Ordovician
79
Devonian
73
Triassic
73
Mississippian
68
Proterozoic
52
Cambrian
51
1879-1955
50
18th century
48
Oligocene
48
Holocene
44
Carboniferous
42
1809-1882
41
Pliocene
38
17th century
35
Silurian
35
Archaean
30
1564-1642
27
Neogene
26
1642-1727
23
21st century
23
Paleocene
23
1838-1914
16
1885-1962
16
To 1500
13
1854-1912
12
1904-1967
11
Paleogene
11
1571-1630
10
1887-1920
10
1473-1543
9
1886-1948
9
1918-1988
9
1928-
9
1834-1902
8
1887-1961
8
more ...