1.2.1. Infraclass Palaeognathae:
This group includes the flightless birds such as ostriches, emus, and kiwis. They are known for their ancient lineage and unique characteristics.
1.2.2. Infraclass Neognathae:
This group includes the vast majority of bird species and can be further subdivided into two superorders: Galloanserae and Neoaves.
1.3. Superorder Galloanserae:
This superorder includes waterfowl (ducks, geese, and swans) and landfowl (chickens, turkeys, and pheasants). These birds are often characterized by their heavy, stout bodies and webbed feet.
1.4. Superorder Neoaves:
Neoaves is the largest and most diverse superorder, comprising over 95% of all bird species. It encompasses a vast array of birds, from sparrows and pigeons to eagles and hummingbirds. Neoaves can be further divided into several orders.