Big Paws Only Dog Forums

Hi all, new user here.  I have a 4 month old puppy that I adopted from a shelter about a month ago.  They told me he is a bull dog mix, but many have said that is untrue.  After some research it appears he has newfoundland in him based on his markings, head shape and muzzle area.  Only thing is that he is short haired so hes probably mixed.  Any ideas?  A lot of people ask does he have dewclaws, so that answer is yes. The first pic is him approx 2 months old.....the second is the most recent at 4 months.  Thanks for any input.

EDIT: I also just noticed he has webbed toes on his feet