The Tertiary period saw a gradual worldwide cooling of climate from tropical temperatures in the Paleocene to more moderate temperatures. Tectonic plate movement was ongoing, including the complete breakup of Gondwana and the collision of India with Eurasia. Life during the Tertiary included modern birds beginning to emerge, the rise of placental mammals, snakes, teleost fish and pollinating insects, as well as the existence of grasses and flowering plants, but did not yet include human beings.