Llanocetidae is an extinct

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of ancient toothed

baleen whale Baleen whales (), also known as whalebone whales, are marine mammals of the order (biology), parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankt ...

s from the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

. It was named by American paleontologist Edward Mitchell in 1989 after describing the Antarctic ''

Llanocetus ''Llanocetus'' ( "Llano's whale" ) is a genus of extinct toothed baleen whales from the Late Eocene of Antarctica. The type species, ''Llanocetus denticrenatus'', reached gigantic proportions, with the juvenile specimen reaching an estimated in ...

'', but a 2018 study by paleontologists

Ewan Fordyce Robert Ewan Fordyce (14 July 1953 – 10 November 2023) was a New Zealand palaeontologist. He specialised in the evolution of whales, dolphins, and early penguins. Life and career Fordyce joined the Department of Geology at the University of ...

and Felix Marx included the Peruvian '' Mystacodon'' and an undescribed New Zealand specimen OU GS10897.

References

Baleen whales Eocene cetaceans Fossil taxa described in 1989 {{Paleo-whale-stub