Landfowl survived the asteroid by staying toothless and earthbound
Galliformes—landfowl—are heavy terrestrial birds with about 290 species in five families, from chickens and pheasants to megapodes and guineafowl. Together with waterfowl they form Galloanserae. Their ground-dwelling, toothless ancestors outlived tree-ruling enantiornithes when the end-Cretaceous impact cleared the skies.
The order name comes from Gallus, Latin for rooster. Phasianidae now fold in grouse and turkeys as recent offshoots of partridge-like stock; New World quail, cracids, and incubator megapodes complete the living set. Sexual dimorphism is strong, males often flashy courters; most species skip long migration and flee on foot before they fly. They seed and hunt insects across every continent but Antarctica, absent only from inner deserts and permanent ice. Red junglefowl became chickens; wild kin remain upland game.
Galloanserae sit basally among living neognaths after the ratites. Sibley–Ahlquist Craciformes splitting cracids and megapodes is rejected as a phenetic artifact. Buttonquails, mesites, and the hoatzin once sat here wrongly. Austinornis lentus from Texas chalk about 85 million years ago is a pangalliform relative, not crown Galliformes; Argentine coracoid PVPH 237 near 90 million years hints the same branch. Paleogene families Gallinuloididae, Paraortygidae, and Quercymegapodiidae filled early Cenozoic niches.
True galliforms appear by mid-Eocene around 45 million years ago and replace older cousins by the early Neogene. Because early fossils already look phasianid—the youngest living family—other families must be at least Early Eocene and could be Late Cretaceous. Modern phasianid genera emerge near the Oligocene–Miocene boundary some 25–20 million years ago. From malleefowl mounds to peacock trains, the clade that hid on the ground still dominates humanity's barnyards, markets, and busy game bags.
Source: Galliformes
