Neornithes are the most recent common ancestor of all living birds and all their descendants. There are about 9,000 to 10,000 known living species in the world.

…birds, assigned to the infraclass Neornithes, or Carinata. Living alongside Hesperornis and other Odontornithes was a group of flying birds that included Ichthyornis and Apatornis . Although not related to gulls, these birds resembled them superficially and may well have been their ecological counterparts.

All modern birds lie within the crown group Aves (alternately Neornithes), which has two subdivisions: the Palaeognathae, which includes the flightless ratites (such as the ostriches) and the weak-flying tinamous, and the extremely diverse Neognathae, containing all other birds. [55]

Birds (Aves) are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich. They rank as the class of tetrapods with the most …

Neornithes is the most diverse group of vertebrates with over 10,000 species. They are divided into two major groups: Palaeognathae (flightless birds) and Neognathae (all other birds). The majority of Neornithes possess a unique respiratory system involving air sacs that allow for efficient oxygen exchange.

Neornithes was originally proposed as a replacement for Ornithurae by Gadow in 1892 and 1893. Gauthier and de Queiroz, therefore, consider Neornithes a junior synonym of Ornithurae, [ 4 ] though many other scientists use Neornithes to refer to the much more restrictive crown group consisting only of modern birds (a group for which Gauthier uses ...

2004年6月10日 · In this review we highlight current understanding of the early fossil history of Neornithes in conjunction with available phylogenetic resolution for the major extant clades, as well as recent advancements in genetic methods that have constrained time estimates for major evolutionary divergences.

2014年3月15日 · Knowledge of the evolutionary history of crown group birds (Neornithes) has significantly improved through emerging congruence among phylogenetic hypotheses and the description of numerous new Palaeogene stem group representatives.

During the Mesozoic, several extinct lineages of birds shared the world with early Neornithes. The Ichthyornithiformes could fly and bore teeth in the jaws; known forms seem to have resembled gulls in their lifestyle, if not their structure.

2024年12月8日 · Higher-order phylogeny of modern birds (Theropoda, Aves: Neornithes) based on comparative anatomy. II. Analysis and discussion. Zoological Journal of the Linnean Society 149(1): 1–95. DOI: 10.1111/j.1096-3642.2006.00293.x PMC: 2517308. PMID: 18784798. Reference page.