The ancestors of modern whales made their transition from land to sea about 53 million years ago. Now, a new study from San Diego State University has found that, at one point during the middle of this transition, the whales had their mouths full of teeth along with beards. Boths. Let us remember that blue, humpback and gray whales are born without teeth because they have what we know as a beard, a series of plates composed of hair-like structures that grow from the roof of the mouth and that serve as a sieve to filter their food. But they have teeth in the womb.
Now we know that it was not always like this, that embryonic teeth are evidence of a time when ancient whales did possess teeth and consumed larger prey.
For this study, the researchers used the technique of computed tomography (CT) high resolution scan to scan a 25 million year old fossilized whale skull that belonged to Aetiocetus weltoni, an evolutionary “cousin” of modern whales now extinct and whose fossils were found north of the Pacific, in Orégón (USA). USA). The analysis revealed that he had teeth and beards at the same time in adulthood.
This transitional fossil was therefore discovered along the Oregon coast by graduate students of the Museum of Paleontology at the University of California, Berkeley, and loaned to the biologist and lead author of the study, Eric Ekdale, of the State University of San Diego, and paleontologist Thomas Deméré of the San Diego Museum of Natural History. Since beards decompose and are rarely preserved intact in fossils, scientists had to base their experiments on digital reconstructions with CT images to look for evidence of barbs in Aetiocetus,whose skull had about forty-four teeth (molars with crowns, curved canines and incisors). The study revealed grooves and holes in the roof of the mouth that connect internally with a vascular canal in a manner consistent with the pattern of blood vessels leading to whiskers in modern specimens.
The study also revealed separate connections that would have brought blood to the upper teeth, which is consistent with the pattern of blood supply to the teeth of tooth-bearing whales such as sperm whales and killer whales, porpoises or even dolphins.