Radiometric Dating Corroboration

At the risk of terminal thread drift, here's a nifty graph I came across in researching TC's mantle model: The red squares represent major episodes of flood basalt eruptions. The arrows represent extinction events. The sceptical question to ask at this point is whether there are many more extinction events, and the author just picked out the ones that happened to line up with flood basalts? Or are there many flood basalt eruptions and he picked out the ones that line up with extinction events?If this really is a concise record of extinctions and flood basalts, then the link between them seems unassailable.from http://www.firstscience.com/site/articles/self.aspalso see the table here: http://www.geolsoc.org.uk/template.cfm?name=fbasalts