Well there is a very good reason why we do not. Paleontology is not a science, it a self-fullfilling prophecy. If it has 3 earbones then they call it a mammal - even though they do not have the slightest idea whether it had mammary glands or not. Take the platypus again - it lays eggs. If it was not a living being paleontologists would say that it gave live birth - because what the heck it had 3 earbones. We know exceedingly litle about extinct species. In spite of lots of good dinosaur specimens we do not know if they had mammary glands, we do not know if they had scales, feathers, green skin, brown skin, purple skin, we do not know if they were warm blooded or cold blooded and a hundred other characteristics which are very much a part of a species, very much a part of the genome of a species and very much the concern about someone really trying to determine if evolution is true.
LOL! Ouch.
And they do that despite all the modern non-mammalian species running and flying around that gore3000 can name with hammer-anvil-stirrup earbones. Show those evos no mercy, gore! Start naming them!
Evolution says that mammary glands on a dinosaur would be stunningly unlikely. Please do not skip this next question, it's very revealing of what's going on here. Do you understand what you are arguing against, evolutionary theory, well enough to say why mammary glands on a dinosaur are basically excluded? (Here it is again. Evolution has something to tell us. In ID/creationism, anything goes.)
. . . we do not know if they had scales, feathers, green skin, brown skin, purple skin,
There are instances of skin impressions.
. . . we do not know if they were warm blooded or cold blooded and a hundred other characteristics which are very much a part of a species . . .
In many cases, we have bone evidence of warm-bloodedness in later dinosaurs. There are many things, such as just for one example whether two similar creatures would have been sexually compatible or had completely speciated, it cannot tell us. So what? You want too much for the incompleteness of the available data. That's a problem for all serious theories equally.