Ynnin were uplifted 850 000 years ago by the Thennanin, who found a culture akin to a neolithic trading society on planet Ynn. Both male and femal Ynnin have a kangaroo-like posture and gait.

Proto-Ynnin lived in herds of about twelve to forty females and young. During mating, matrifocal herds dissolved as males competed for prime territory, displayed and gathered temporary brood herds. As omnivores they ate grubs and scavenged meat as well as scrub and grass.

Ynnin seem earnest and fanatical but scrupulously fair, but they can also be very idealistic. They have become excellent ecologists, an aim that permeates their culture. Often serve individual Thennanin as bodygurads and administrative aides.

Sources: Contacting Aliens, An Illustrated Guide to David Brin's Uplift Universe, The Uplift War, GURPS Uplift,