Era
Cretaceous
96
From 65 to 140 million years ago
60
Pleistocene
51
Tertiary
42
Jurassic
41
Miocene
34
Mesozoic
32
Cenozoic
29
Paleozoic
29
Devonian
28
Ordovician
28
Eocene
26
From 140 to 190 million years ago
24
From 2 to 65 million years ago
23
Carboniferous
22
From 10 thousand to 2 million years ago
21
From 230 to 570 million years ago
20
Cambrian
19
From 425 to 500 million years ago
19
Permian
18
Quaternary
18
Triassic
18
Silurian
16
From 10 to 25 million years ago
15
Oligocene
15
From 280 to 345 million years ago
14
From 345 to 405 million years ago
14
From 40 to 55 million years ago
13
19th century
12
From 65 million years ago
11
Holocene
11
From 65 to 230 million years ago
10
Mississippian
10
Pliocene
10
From 190 to 230 million years ago
9
Paleocene
9
From 2 to 25 million years ago
8
From 310 to 345 million years ago
8
Neogene
8
Precambrian
8
From 500 to 570 million years ago
7
20th century
6
From 2 to 10 million years ago
6
From 230 to 280 million years ago
6
Pennsylvanian
6
From 405 to 425 million years ago
5
From 280 to 310 million years ago
4
1810 or 1811-1889
3
18th century
3
From 10 to 40 million years ago
3
more ...