Indeed, "sea raven" or analogous terms were the usual terms for cormorants in Germanic languages until after the Middle Ages.The French explorer André Thévet commented in 1558, "..beak [is] similar to that of a cormorant or other corvid," which demonstrates that the erroneous belief that the birds were related to ravens lasted at least to the 16th century. They range in size from the pygmy cormorant (Phalacrocorax pygmaeus), at as little as 45 cm (18 in) and 340 g (12 oz), to the flightless cormorant (Phalacrocorax harrisi), at a maximum size 100 cm (39 in) and 5 kg (11 lb).They range around the world, except for the central Pacific islands.
Their relationships and delimitation – apart from being part of a "higher waterfowl" clade which is similar but not identical to Sibley and Ahlquist's "pan-Ciconiiformes" – remain mostly unresolved.
Notwithstanding, all evidence agrees that the cormorants and shags are closer to the darters and Sulidae (gannets and boobies), and perhaps the pelicans or even penguins, than to all other living birds.
They dive from the surface, though many species make a characteristic half-jump as they dive, presumably to give themselves a more streamlined entry into the water.
Under water they propel themselves with their feet, though some also propel themselves with their wings (see the picture, After fishing, cormorants go ashore, and are frequently seen holding their wings out in the sun. They typically have deep, ungainly bills, showing a greater resemblance to those of the pelicans, to which they are related, than is obvious in the adults.
is followed here for three reasons: first, it is preferable to tentatively assigning genera without a robust hypothesis.