LiveScience.com – The last place scientists expected to find the fossil of a freshwater, tropical turtle was in the Arctic. But they did.

AP – Pleurocoelus has served ably as the official dinosaur of Texas. Sure, it was a plant-noshing herbivore in a fiercely barbecue-proud state, but the sauropod dwarfed most other dinos and lumbered with a 20-ton swagger.

A recent study by researchers in England has found that scientists’ knowledge of the evolution of dinosaurs is remarkably complete.