When you explore the tree of life, one thing you will notice is that it has many extinct species. Consider terrestrial vertebrates for example... http://www.t

When you explore the tree of life, one thing you will notice is that it has many extinct species. Consider terrestrial vertebrates for example... http://www.tolweb.org/Terrestrial_Vertebrates/14952 http://www.tolweb.org/Terrestrial_Vertebrates/14952