Anseriformes are one of two types of modern bird thought to be confirmed present during the Mesozoic alongside the other dinosaurs, and in fact were among the very few birds to survive their extinction, along with their cousins the galliformes. These two groups only occupied ecological niches during the Mesozoic, living in water and on the ground, while the toothed enantiornithes were the dominant birds that ruled the trees and air. But the fireball that is thought to have ended the era of the dinosaurs destroyed all trees as well as animals in the open, a condition that took years to recover. The anseriformes and galliformes are thought to have survived in the cover of burrows and water, and not to have needed trees for food and reproduction.
The earliest Cretaceous anseriform found so far is Vegavis, a goose-like waterfowl thought to have lived as long as 99 million years ago. Some members apparently surviving the KT extinction event, including presbyornithids, thought to be the common ancestors of ducks, geese, swans, and screamers, the last group once thought to be galliformes, but now genetically confirmed to be closely related to geese. The first known duck fossils start to appear about 34 million years ago.