How far back does the evolutionary history of Anseriformes extend?

Anseriformes represent an ancient lineage of birds. Fossil and genetic evidence indicates that their ancestors were among the earliest lineages in the evolution of modern birds, extending back to the Cretaceous Period more than 65 million years ago.1

While the order's roots are deep, the rich fossil record for modern waterfowl begins later, during the Late Eocene Epoch, which occurred approximately 37 to 33.7 million years ago.1