Recently I found TimeTree (http://www.timetree.org/ http://www.timetree.org/). The tool produces both timelines and timetrees (ancestry) of taxonomies. Both t

Recently I found TimeTree (http://www.timetree.org/ http://www.timetree.org/). The tool produces both timelines and timetrees (ancestry) of taxonomies. Both tools provide a nice context of the evolutionary environment. If you click through enough, you can usually get to the underlying research for the data as well. Try searching for taxons Spermatophyta (seed plants) and Magnoliophyta (flowering plants) and to see the common ancestor of flowering plants.