Era
20th century
30
19th century
11
21st century
8
Pleistocene
6
18th century
4
1901-1966
4
1945-1989
4
Cretaceous
4
Ordovician
4
Permian
4
Triassic
4
1866-1943
3
1929
3
1969-1974
3
Pennsylvanian
3
To 1500
3
1809-1882
2
1865-1936
2
1903-1950
2
1933-1945
2
1934-2013
2
1935-
2
1941-
2
1954-
2
1965
2
1969-
2
Mesozoic
2
Miocene
2
Oligocene
2
Pliocene
2
Silurian
2
Tertiary
2
-1423
1
1517-1882
1
1632-1677
1
1667-1745
1
1724-1804
1
1734-1815
1
1775-1817
1
1783-1865
1
1785-1851
1
1792-1822
1
17th century
1
1804-1881
1
1812-1870
1
1830-1904
1
1833-1909
1
1838-1926
1
1846-1920
1
1847-1931
1
more ...