Scientists have a relatively precise idea about where whales and their closest terrestrial relatives evolved more than 50 million years ago (early Eocene), thanks to the discovery of ancient cetacean fossils in India and Pakistan. Around 45 million years ago, four-legged whales (protocetids) gradually dispersed out of Asia, westward towards Africa and then reached the east coast of North America more than 41 million years ago.
![]() |
View of the locality Media Luna, where Peregocetus was discovered, in the Pisco Basin, coastal Peru, at the beginning of the excavation, in November 2011 [Credit: O. Lambert] |
Lead author, Olivier Lambert, Royal Belgian Institute of Natural Sciences, Bruxelles,Belgium, presented the team's findings at this year's annual meeting of the Society of Vertebrate Paleontology held this year in Brisbane, Australia.
The importance of primitive whale, Peregocetus pacificus, lies in its completeness, location and age. This specimen represents the earliest skeleton of an amphibious whale from South America (and the whole Pacific).
![]() |
View of the excavation of the skeleton of Peregocetus in Media Luna, with the Pacific Ocean in background [Credit: C. de Muizon] |
Sharing similarities with some western African protocetids, Peregocetus pacificus, supports the hypothesis that early quadrupedal whales crossed the South Atlantic from Africa to South America over 40 million years ago.
These early whales nearly attained a circum-equatorial distribution with a combination of terrestrial and aquatic locomotion abilities less than 10 million years after their origin in south Asia. Using large, most likely webbed feet with long toes, Peregocetus likely used its hindlimbs for underwater locomotion.
![]() |
Another view of the excavation of the skeleton of Peregocetus. Mario Urbina, the discoverer of the locality and whale is on the right [Credit: G. Bianucci] |
Source: Federation of American Societies for Experimental Biology [November 08, 2019]
No comments: