PANAMA..more than 500 fossils including teeth and bones of rodents, horses, crocodiles and turtles...

A fossilized stalk, recently discovered by the Panama Smithsonian Research Institute, is seen at Panama Canal in this handout released to Reuters July 17, 2008. Engineers digging to widen the Panama canal have uncovered more than 500 fossils including teeth and bones of rodents, horses, crocodiles and turtles that lived before a land bridge linked North and South America.

A fossilized seed, recently discovered by the Panama Smithsonian Research Institute, is seen at Panama Canal in this handout released to Reuters July 17, 2008. Engineers digging to widen the Panama canal have uncovered more than 500 fossils including teeth and bones of rodents, horses, crocodiles and turtles that lived before a land bridge linked North and South America.

Recently discovered fossilized jaw of a crocodile teeth are seen at Smithsonian Research Institute in Panama City, July 17, 2008. Engineers digging to widen the Panama canal have uncovered more than 500 fossils including teeth and bones of rodents, horses, crocodiles and turtles that lived before a land bridge linked North and South America.

A recently discovered fossilized jaw of a carnivore is seen at Smithsonian Research Institute in Panama City, July 18, 2008. Engineers digging to widen the Panama canal have uncovered more than 500 fossils including teeth and bones of rodents, horses, crocodiles and turtles that lived before a land bridge linked North and South America.