If you were a small animal, the late cretaceous would have been an awful time to be around. 

 

For a youngster, every day is a struggle to stay alive. Their only chance is to keep out of trouble and grow up fast. 

 

If you’re a Tyrannosaur, every mega herbivore in the environment wants to crush you. 

 

Dinosaurs develop advanced tools to survive, astonishing on the outside and on the inside. And now 65 million years on, cutting-edge imaging technology will peel back skin, muscles and bones to reveal the secrets of nature’s greatest success story. 

 

The largest dinosaurs grow as tall as a 6-storey building, and weigh 50 tons or more. No land animal today even comes close. The jaws of a T-Rex could leave a bite mark over a meter long, and its 30-centimeter teeth could penetrate deep into flesh. But every dinosaur no matter how big or powerful begins life very small. 

 

Oklahoma, 110 million years ago, a herd of sauroposeidon dinosaurs are on the move.

 

We’re talking about an animal who’s probably 80 or 90 feet long, and about 40 feet of that was just neck, so when it stuck its neck straight up, it could probably reach about 6 feet up in the air. 

 

These leviathans are making a journey to nesting sites they’ve used for generations. And developing inside them are hundreds of eggs. They are the future of a species that will be around for 15 million years, more than 75 times longer than humans have been on earth. Yet each egg is no larger than a cantaloupe melon.