Neornithes

Definition

Neornithes are the clade that includes all modern birds. They are characterized by advanced flight adaptations, such as a keeled sternum and lightweight bones.

5 Must Know Facts For Your Next Test

1. Neornithes is the most diverse group of vertebrates with over 10,000 species.
2. They are divided into two major groups: Palaeognathae (flightless birds) and Neognathae (all other birds).
3. The majority of Neornithes possess a unique respiratory system involving air sacs that allow for efficient oxygen exchange.
4. Feathers in Neornithes serve multiple purposes including flight, insulation, and mating displays.
5. Neornithes exhibit a wide range of reproductive strategies but generally lay eggs with hard shells.

Review Questions

Related terms

Palaeognathae:

A subgroup of Neornithes comprising primarily flightless birds like ostriches and emus

Neognathae: The largest subgroup within Neornithes, including all modern flying birds

Keel: A specialized structure on the sternum of many birds to which flight muscles attach