Era
20th century
20
19th century
8
1950-
6
1945-
5
21st century
5
18th century
4
1923-
4
1938-
4
1946-
4
1859-1938
3
1902-1979
3
1925-
3
1926-
3
1932-
3
1941-
3
1949-
3
Early modern, 1500-1700
3
16th century
2
17th century
2
1859-1952
2
1860-1936
2
1865-1939
2
1879-1955
2
1885-1962
2
1901-1980
2
1902-1995
2
1906-1987
2
1908-1996
2
1909-2000
2
1910-1995
2
1912-
2
1914-1989
2
1914-1994
2
1916-
2
1918-
2
1918-1998
2
1927-2008
2
1928-
2
1928-1990
2
1928-2001
2
1928-2009
2
1929-
2
1937-
2
1940-
2
1944-
2
1947-
2
1948-
2
1953-
2
1955-
2
Cenozoic
2
more ...