My source is in post #151. When you ask again, and again, and again, the answer will still be post #151.
At least you managed to finally grasp the difference between "broad" and "specific," so I suppose there is some remote hope for you yet.
Post 151 simply links to a site that sells replicas of Crocodile skulls and contains the super scientific statement that "Crocodiles first appeared nearly 160 million years ago and have changed very little since."
It says nothing at all about mutation rates. What is your reference for your assertion that crocodiles have a low mutation rate? Do you not understand the concept?