In a galaxy very far away, two planets were born in a fiery collision and began to circle a yellow sun. One was watery while the other was hot and arid, but life was tenacious, and managed to develop slowly on both worlds. On the watery planet, fish crawled from the sea and became amphibians, then grew greenish fur to protect them from the cold, and finally walked upright and bore patches of green hair only on their heads. On the arid planet, creatures like large slugs developed bones from their cartilage, crept through the desert as lizards, and finally evolved into red-furred creatures with cat-like faces and monkey's limbs. On both planets the natives grew more intelligent, learned about trade and war, and sang songs celebrating their exploits. The centuries went by, and eventually it was inevitable that two civilizations living so close to each other would find a way to meet. the history of all civilizations could have predicted that their meeting would not be peaceable...
Used availability for Michael Kurland's First Cycle
January 1982 : USA Mass Market Paperback