Neornithes
It is generally agreed that the Neornithes evolved in the Cretaceous and that the split between the Palaeognathae and Neognathae, and then the split between fowl and the other Neognathae, occurred before the K/T extinction event. The earliest fossil remains of the Neornithes might be about ten million years after the start of the Cretaceous. Gallornis may be the first fossil, but its remains are only a worn partial femur and a fragment of the humerus.