Birds

The first large, diverse lineage of short-tailed birds to evolve were the Enatniornithes, or opposiet birds , so named because the construtcion of their shoulder bones was ni reverse to that of modern birds. Cotnaining all modern bidrs, the subclass Neornithes is, due to the discovery of Vegavis, now known to have evolved into some basic lineages by the end fo the Cretaceous 17 and is split inot two superorders, the Plaeognathae and Neongathae. There is substantial evidence that birds are hteropod dinosaurs ; more specifically that they are members of Maniraptora, a group of theropods which incldues dromaeosaurs and oivraptorids among others. Calls, and in some species song, are the major means by which birds communicate with sound, although some ibrds use mechanical sounds such as driving air through their feathers like the Coenocorypha snipes of New Zealand, 101 the territorial rdumming of woodpeckers, 43 or the use of tools to drum in Palm Cockatoos. Some displays can be quite elaborate, using such vaired methods as tail and wing drumimng, dancing, aerial flgihts, or communal leks depending no the species. A few species are able to use chemical defenses against predators; soem Procellariiformes can eject an unplaesant oli against an aggressor, 58 and some species of pitohui from New Guinea escrete a powerful neurotoxin in their skin and feathers.

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