It was 36 million years ago that whales began to lose their teeth


Many do not know, but the ancestors of the present great whales had teeth, hunted and chased prey, thus indicated the analysis done to a 36.4 million-year-old whale fossil found in southern Peru.

The study was published this week in the journal Current Biology, but it is not explained concretely at what point the whales lost their teeth and evolved into the animals we know today, with bristles that serve to filter water and collect food, However, it is said that there was a past with whales that had hind limbs, which fed by suction and that dived to hunt the prey.

This fossil, discovered in the Pisco Basin in southern Peru, belonged to the oldest known member of the group of the cetaceans misticetos, this being a suborder that includes the Blue Whale, the Whale of Bossa or the Whale Free.

At about 4 meters in length, this late Eocene animal (between 55 and 36 million years ago) was much smaller than its current relatives, however, very different from the skull. Present whales do not have teeth, but keratin fibers, known as ‘beards’, serve to trap small marine animals from which they feed.

“This finding by our fellow Peruvian Mario Urbina fills a gap in the history of the group and provides clues about the ecology of the early mystic”, said paleontologist and co-author of the study Olivier Lambert of the Royal Belgian Institute of Natural Sciences.

According to the official, quoted in the magazine, the fossil study also suggests that, in addition to teeth, the whale would also have specialized in suction feeding, since their teeth exhibit a pattern of wear relatively different from that found in whales even more Old.

The members of these species, classified as “basilosauridae”, were active hunters, similar to the current killer whales, had mouths suitable for biting and also attacking. The whale whose fossil was now discovered in Peru had a more adequate mouth to suck food, prompting researchers to conclude that it represents an intermediate step between predatory and current whales.

Lambert recalled those who criticize the theory that whales come from a terrestrial ancestor to say that the now discovered fossil reveals the intermediate steps of the evolution of the species.

Another surprise of the “his” whale was the finding of hind limbs, although atrophied, something that palaeontologists thought disappeared in the “basilosauridae”.