In comparison with all other vertebrates the number of neck-vertebrae of the birds is considerably increased; the lowest number, 14 to 15, is that of most Passeres and many other Coraciomorphae; the largest numbers, 20 or 21, are found in the ostrich, 23 in Cygnus olor and 25 in the black swan.
A gigantic swan, Cygnus falconeri, is known from the Zebug cavern in Malta.
Anser, Anas, Cygnus, since Miocene.
Conspicuous among these are the great white swan (Cygnus anatoides), the black-necked swan (Anser nigricollis), the antarctic goose (Anas antarctica) and the " race-horse " or " steamer duck " (Micropterus brachypterus).
19 northern: - Ursa major, Ursa minor, Bootes, Draco, Cepheus, Cassiopeia, Andromeda, Perseus, Triangulum, Pegasus, Delphinus, Auriga, Hercules, Lyra, Cygnus, Aquila, Sagitta, Corona and Serpentarius; 13 central or zodiacal: - Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, Pisces and the Pleiades; and 12 southern: - Orion, Canis, Lepus, Argo, Cetus, Eridanus, Piscis australis, Ara, Centaurus, Hydra, Crater and The Phoenicians - a race dominated by the spirit of commercial enterprise - appear to have studied the stars more especially with respect to their service to navigators; according to Homer " the stars were sent by Zeus as portents for mariners."
In the 5th century B.C. the Athenian astronomer Euctemon, according to Geminus of Rhodes, compiled a weather calendar in which Aquarius, Aquila, Canis major, Corona, Cygnus, Delphinus, Lyra, Orion, Pegasus, Sagitta and the asterisms Hyades and Pleiades are mentioned, always, however, in re Corvus.
The names in which Ptolemy differs from modern usage are: - Hercules (iv -yovaotv), Cygnus ("Opvts), Eridanus (IIora tos), Lupus (Onpiov), Pegasus (17r7ros), Equuleus ("Iirirov irporogi i), Canis minor (IIpoidwv), and Libra (XnXai, although "vyos is used for the same constellation in other parts of the Almagest).