Historical Period
Quaternary
43
Paleozoic
39
Cretaceous
38
Pleistocene
38
Precambrian
37
Devonian
24
19th century
23
Cambrian
18
Ordovician
18
Cenozoic
17
Mesozoic
17
Tertiary
17
Silurian
15
Carboniferous
13
Neogene
9
Permian
9
18th century
8
Holocene
8
Mississippian
8
Triassic
8
Jurassic
7
1726-1797
6
Eocene
6
Pliocene
6
1809-1882
5
Miocene
5
17th century
4
20th century
4
Proterozoic
4
1848-1860
3
Pennsylvanian
3
1797-1875
2
Archaean
2
1635?-1715
1
1638-1686
1
1714-1837
1
1730-1811
1
1761-1817
1
1761-1841
1
1763-1840
1
1769-1828
1
1776-1842
1
1805-1877
1
1808-1890
1
1813-1895
1
1820-1895
1
1839-1914
1
1841-1922
1
1843-1918
1
1849-1901
1
more ...