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The new tools of molecular biology changed the study of bird systematics, which changed from being based on phenotype to the underlying genotype. The use of techniques such as DNA–DNA hybridization to study evolutionary relationships was pioneered by Charles Sibley and Jon Edward Ahlquist, resulting in what is called the Sibley–Ahlquist ...
The study of birds is called ornithology. Birds are feathered theropod dinosaurs and constitute the only known living dinosaurs . Likewise, birds are considered reptiles in the modern cladistic sense of the term, and their closest living relatives are the crocodilians .
In the United States, the collection and possession of wild bird eggs is also restricted, and in some cases is a criminal act. Depending on the species, the Migratory Bird Treaty Act , [ 17 ] the Lacey Act , [ 18 ] the Endangered Species Act , [ 19 ] or other laws may apply.
Bird collections are used for a wide variety of purposes. All biological species including those of birds are represented by a holotype, the vast majority of which are full specimens (mostly skins) and in modern times explicitly designated in the original description of the taxon. All other putative members of the species may be compared to the ...
As the bird stem group evolved, distinctive bird features such as feathers and hollow bones appeared. Finally, at the base of the crown group, all traits common to extant birds were present. Under the widely used total-group perspective, [ 17 ] the Crocodylomorpha would become synonymous with the Crocodilia, and the Avemetatarsalia would become ...
Systematic biology (hereafter called simply systematics) is the field that (a) provides scientific names for organisms, (b) describes them, (c) preserves collections of them, (d) provides classifications for the organisms, keys for their identification, and data on their distributions, (e) investigates their evolutionary histories, and (f ...
The ratites are mostly large and long-legged, flightless birds, lacking a keeled sternum. Traditionally, all the ratites were place in the order Struthioniformes . However, recent genetic analysis has found that the group is not monophyletic, as it is paraphyletic with respect to the tinamous , so the ostriches are classified as the only ...
In biology, a taxon (back-formation from taxonomy; pl.: taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking , especially if and when it is accepted or becomes established.