A: This animal is the largest of any mammal.
vs.
B: This animal is the largest of all mammals.
What are the subtle differences between A and B?
A: This animal is the largest of any mammal.
vs.
B: This animal is the largest of all mammals.
What are the subtle differences between A and B?
There is no difference. In sentence A, 'any' in effect means 'all', which makes sentences A and B equivalent in meaning.