Some did. American oral traditions describe Mishipishu, the stegosaur, as having red fur:
I'm just being skeptical. Dinosaur skeletons appear to have more in common with birds and reptiles than mammals. Yet there are very, very few complete dinosaur skeletons. And it's from the skeletons where we get 99.9 percent of what know of dinosaurs. Did dinosaurs have fur?
Here's the problem: The ancestors of mammals branched off the reptilian trunk way far back before the diapsids, much less the dinos, were a distinct branch.
That's the theory.
That's what I mean when I say you don't inherit from your cousins. By the time the ancestors of mammals were becoming mammals, the dinos were on a very different branch. How do the mammaries get across the tree?
If mammaries developed for some reason for some species, why not for another. Why do some sharks lay eggs and others give birth live (albeit without nursing?)
The only goal is survivability right now. What works, works, but just for right now. Multicellularity can work better for some species, some times. We still have examples of animals like slime molds, Volvox, and others which are only barely or only part-time multicellular.
But algae and bacteria remain with us. And they can exists whereever more "advanced" lifeforms exists and in places they can't.
No. Scales, mostly. Some later ones had feathers. Some later yet are hard to tell from birds. Some later yet are in your backyard looking for worms.
If mammaries developed for some reason for some species, why not for another.
Mammals appear to be highly modified sweat glands. Ever see a bird sweat? Never mind Gilbert and Sullivan's "And a cold perspiration bespangled his brow! Oh willow! Tit willow! Tit willow . . ."
But algae and bacteria remain with us. And they can exists whereever more "advanced" lifeforms exists and in places they can't.
Yes, so? Have you studied anything about evolution outside of creationist/ID propaganda?
Some did. American oral traditions describe Mishipishu, the stegosaur, as having red fur: