I'm trying to remember the title of a book I read approximately 15 years ago. My memory of the plot is a bit hazy, but it centered around time-travel. If I recall correctly, in the story people would travel back in time for recreational purposes, observing some sort of protocol to avoid changing future events. One person ignores this protocol, and "corrupts" the space-time continuum.
As a result of this a race of sentient dinosaurs develop and become a major element in the plot. The few specific details that I remember about the story come from around this point. I'm fairly certain that there is mention made of the dinosaurs warring with primitive human tribes (in particular, the humans may have been described as Japanese or samurai warriors) using spears and other early weapons.
More specifically, at some point the dinosaurs capture and imprison a human woman, I believe from the future along the original, non-corrupted timeline. While in captivity she observes their culture and attempts to learn their language. The first/most prominent dinosaur she speaks with has an anthropomorphized name of "Struth", I believe, with the actual pronunciation in dino-speak being slightly different.
After some time she is given an opportunity to gain acceptance into their society by completing an initiation ritual. She is given a dull ceremonial knife and a bowl and no instructions, and is left to work out the requirements of the ritual on her own. What she eventually does is use the knife to cut her hand/arm, collecting her blood in the bowl. Once she has collected as much blood as she feels she can safely part with, she then proceeds to take the bowl and dump it out on top of the dinosaurs' elder/tribal leader.
Those are about the only specifics I remember. It's probably not much to go on, but does anyone have any idea what book this might have been?