Species extinctions are about 1,000 times more frequent now than in the 60 million years before humans came along.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/species-extinction-rates-1000-times-higher-pre-human-period-says-study
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/sudan-vision-sudan
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/biodiversity
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/extinct-species
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/flora
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/fauna