Tropicbirds

The Phaethontiformes are an order of birds. They contain one extant family, the tropicbirds (Phaethontidae), and one extinct family Prophaethontidae from the early Cenozoic. Several fossil genera have been described, with well-preserved fossils known as early as the Paleocene. The group's origins may lie even earlier if the enigmatic waterbird Novacaesareala from the latest Cretaceous or earliest Paleocene of New Jersey is considered a tropicbird.

Many phaethontiform fossil taxa are known from the Paleocene and Eocene, but the fossil record becomes much more scant after the Oligocene. This suggests that around this time, the group may have moved out of the nearshore habitats where they were easier to fossilize and evolved the pelagic lifestyle that is still retained by the few surviving members today.