No, I addressed the main point you made that there are numerous ways to tell a mammal. There are not, and I addressed that the only one, the three earbones, is not a necessary characteristic for an animal having mammary glands. It is a statistical one only and such statistical ones such as the statement still made by a museum that all mammals have live birth shows that such statistical characteristics are not evidence as the platypus showed. Further, as I pointed out, since it is not a necessary characteristic and since evolution supposedly works in a gradual manner, it cannot be said that any non-extant species had mammary glands or how such an function ever developed in a gradual evolutionary manner.
Oh, and one more thing, they are called mammals because they have mammary glands, not because of their bone structure.
Oh, and one more thing, they are called mammals because they have mammary glands, not because of their bone structure.
It might not be a "necessary" characteristic if one was to design a mammal from scratch, but in the real world the two are invariably, with no exceptions, found together. Mammals could just as easily have been called "animals with three inner ear-bones" or "animals with a single-boned jaw". Those characteristics are just as specific to mammals as mammary glands. Mammary glands are just a little more obvious, that's all. They are no more characteristic of the mammalian group than the earbones or the jaw.
It is a statistical one only and such statistical ones such as the statement still made by a museum that all mammals have live birth shows that such statistical characteristics are not evidence as the platypus showed. Further, as I pointed out, since it is not a necessary characteristic and since evolution supposedly works in a gradual manner, it cannot be said that any non-extant species had mammary glands or how such an function ever developed in a gradual evolutionary manner.
When it comes to extinct species, there are no mathematical proofs. You can use the evidence available to support your conclusion. The bones say they're mammals. There is nothing in the bones that goes against this hypothesis, so it stands. Assuming that evolution explains how the various groups of mammals came to exist, then lactation arose before the three modern groups diverged. And even if I didn't find evolution convincing and believed that God actively created each individual species over hundreds of millions of years, I would still be persuaded by the skeletons that these animals were mammals. The alternative is that some other, unknown, non-mammalian group may have just happened to have the exact same types of skeletons. The evidence says mammal and there is absolutely nothing to suggest that they were anything else, evolution or no evolution.