Phalacrocorax is a genus of fish-eating birds in the cormorant family Phalacrocoracidae. Members of this genus are also known as the Old World cormorants.^[2]

The genus Phalacrocorax was introduced by the French zoologist Mathurin Jacques Brisson in 1760 with the great cormorant (Phalacrocorax carbo) as the type species.^[3][4] Phalacrocorax is the Latin word for a cormorant.^[5]

Formerly, many other species of cormorant were classified in Phalacrocorax, but most of these have been split out into different genera. A 2014 study found Phalacrocrax to be the sister genus to Urile, which are thought to have split from each other between 8.9–10.3 million years ago.^[1]

A molecular phylogenetic study published in 2014 found that the genus Phalacrocorax contains 12 species.^[1] This taxonomy was adopted by the IUCN Red List and BirdLife International, and later by the IOC.^[6]

Formerly, the genus Phalacrocorax often included all members of the family Phalacrocoracidae. More recently, some authorities, such as the Clements checklist, recognized Microcarbo as distinct (due to its morphological distinctiveness and the old age of its split from the remaining cormorants), while retaining all other cormorants in a still-broad Phalacrocorax. The IOC checklist went a step further in recognizing Leucocarbo as well as Microcarbo as distinct (while retaining the rest in Phalacrocorax), but this treatment rendered Phalacrocorax paraphyletic (with some members much more closely related to Leucocarbo than others). Nowadays, due to the age of the splits between different cormorant clades, most authorities, including the aforementioned two checklists, now recognize seven cormorant genera: Microcarbo, Poikilocarbo, Phalacrocorax, Urile, Gulosus, Nannopterum, and Leucocarbo.^[1]