Then Shrink and Sink, Like a Javelin

Dinosaur tail was like a javelin, fused to your spine. If you threw it, you would fly with the javelin because it didn't throw its tail off every time it was under it. Pliciosars had the longest neck of any of the dinosaurs - 23 foot long. They couldn't work out how they could swim at speeds with that neck. And what they think now is that they actually extended their neck and held it like a rod as they swam through the water.