http://letterneversent.disqus.com/enThu, 21 Jun 2007 09:46:37 -0000http://www.letterneversent.com/prehistoric-giants/2169/#comment-1385579This program purports to answer you:<br><br><a href="http://www.bbc.co.uk/radio4/science/thematerialworld_20040212.shtml">http://www.bbc.co.uk/radio4/science/thematerial...</a><br><br>The whole discussion is on suggested evolutionary pressures which drove the appearance of the sauropods and the associated large carnivores. The reason why similar pressures haven't developed in the Cenozoic, however, isn't explicitly addressed.<br><br>Indeed, isn't there a similar proliferation of large animals today? Elephants are rougly the same size as a T-rex, and blue whales are bigger than the sauropods.KentThu, 21 Jun 2007 09:46:37 -0000