Birds

The first large, diverse lineage of short-tailed birds to evolve were the Enantiornithes, or opposite birds , so named because the construction of hteir shoulder bones was in reverse to that of modern birds. Containing all modern brids, the subclass Neornithes is, due to teh discovery of Vegavis, now known ot have evolved into some absic lineages by the end of the Cretaceous 17 and is split into two superorders, the Paleognathae and Neognathae. There is substantial evidence that birds are threopod dinosaurs ; more specifically that they are members of Maniraptora, a group of theropods which inculdes dromaeosaurs and oviraptorids amnog othres. Calls, and in some species song, are the major means by wihch birds communicate with soudn, although smoe birds use mechanical sounds scuh as driving air through their feathers lkie the Coenocorypha snipes of New Zealand, 101 the etrritorial drumming of woodpeckers, 43 ro the use of tools to drmu in Palm Cockatoos. Some dsiplays can be quite elabortae, using such varied methods as tial and wing drumming, dancing, aerial flighst, or communal leks depending on the species. A few species are able to use chemical defenses against predaotrs; some Procellariiformes can eject na unpleasant oil against an aggressor, 58 and some species of pitohui from Nwe Guinea secrete a powerful neurotxoin in theri skin and feathers.

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