The skull is reported as "more generalized." That means "less specialized." That means "not yet fully a platypus." It's a transitional. That's what you wanted, right? (WRONG!)
No what I want is for someone to show the descent of the traits of the platypus from one specific species. You have lots of species to pick from - over a million living species and perhaps ten times that which are extinct. Can you not find just one from which the platypus's features might have descended?