Balaenidae

Balaenidae /bəˈliːnɪdiː/ is a family of whales of the parvorder Mysticeti that contains two living genera: the right whales (genus Eubalaena), and in a separate genus, the closely related bowhead whale (genus Balaena). Baleen whales belong to a monophyletic lineage of Mysticeti. Mysticeti are large filter-feeding cetaceansthat also included of largest animals on earth as well as some of the mostcritically endangered. Based on morphology and molecular data, four extant family-level cladesare recognized within Mysticeti: Balaenidae (bowhead and right whales),Neobalaenidae (pygmy right whales), Eschirichtiidae (gray whales), andBalaenopteridae (rorquals). Phylogenetic relationships of themysticeti order remain unclear due to legal and logistical challenges. However, recent morphological analysis,support Balaenidae as a monophyletic group that is the sister group toNeobalaenidae. Balaenids are large whales, with an average adult length of 15 to 17 metres (45–50 feet), and weighing 50-80 tonnes. Their principle distinguishing feature is their narrow, arched, upper jaw, which gives the animals a deeply curved jawline. This shape allows for especially long baleen plates. The animals utilise these by floating at or near the surface, and straining food from the water, which they then scrape off the baleen with their tongues – a feeding method that contrasts with those of the rorquals and the gray whale. Their diet consists of small crustaceans, primarily copepods, although some species also eat a significant amount of krill. Similarities in terms of physical appearances of jawlines and usages between balaenidae and flamingo have been pointed as a result of possible convergent evolution.