Google Books Ngram Viewer

Graph these comma-separated phrases:
case-insensitive
between and from the corpus with smoothing of .  
Search in Google Books:

1800 - 1880 1881 - 1886 1887 - 1917 1918 - 1994 1995 - 2000 pterosaur English
1800 - 1854 1855 - 1864 1865 - 1871 1872 - 1957 1958 - 2000 pterodactyl English

Run your own experiment! Raw data is available for download here.
© 2013 Google - Privacy & Terms - About Google - About Google Books - About Ngram Viewer