This may not be true. Have you read The Hot Blooded Dinosaurs by Adrian J. Desmond? This posits that dinos (or a lot of them) had similar feeding requirements to predator animals today, as most of them were endothermic, not exothermic like reptiles. Crocs are reptiles and exothermic (most of them), and while they can generate body heat by shivering, there’s a strict limit to how much warmth that can generate.