Many, many years ago, I read a book where dinosaurs were assumed to have suvived the K-T event (or it never happened), and they evolved to intelligent species that used not only language (which combined sound, posture, and colour changes on their skin) but also used technology. In the series, a human is captured or somehow gets integrated with one of the evolved dinosaur groups.
Again, from a very faint memory, the dinosaurs had a level of technology that would be about middle ages, and the humans were much more analogous to American Indian.
That's really all I can recall about the book, and I am trying to find it for my daughter to read. Can anyone help me out?