The England and Wales Census 1871 records the occupation of my gg grandfather Daniel JACKLIN 1842-1897 as 'coprolite labourer'. During this period of the 19th century the Coprolite industry provided plenty of work for the villages such as Orwell and Whaddon, south-west of Cambridge, England.

Updates:
2015-03-08 The original link is broken; here is an alternative at Wikipedia.