"West of Eden" by Harry Harrison.
The dinosaur race is known as the Yilanè. The human-like race, the Tanu, had evolved from new world monkeys instead of apes.
The story continues in two sequels, Winter in Eden and Return to Eden.
The Yilanè, having had millions of years of civilization, have a very
advanced society primarily based on a mastery of the biological
sciences, especially genetic engineering, so much so that almost every
tool and artifact they use is a modified lifeform. Their boats were
originally squids, their submarines are enhanced ichthyosaurs (here
called uruketos), while their guns are modified monitor lizards which
eject projectiles using pressurised gas.