Good point which I'm glad you've raised. For me it comes down to the definition of 'hardness'. Correctly, you point out that the CST is small and snappy and feisty as you put it, but that's like comparing a Jack Russel to a Rottweiler. The alligator Snapper can live for up to 200 years and grow...
The Alligator snapping turtle out-lived the dinosaurs which means whatever cataclysm (think asteroid collision) wiped out those big boys 64 million years ago, well the AST shrugged it off. Ice ages - a minor inconvenience to this bad boy who gave up evolving millions of years ago because....they...