Innovation and Speciation: new amphibious whale found (Evolution)

by David Turell , Friday, August 27, 2021, 17:52 (971 days ago) @ David Turell

In Egypt where a very early group of whale fossils exist, forty million years ago:

https://phys.org/news/2021-08-egyptians-fossil-amphibious-whale.html

"The fossil was found in the Fayum region, a part of Egypt that was once covered by sea and is home to Whale Valley, a UNESCO World Heritage site.

"The newly discovered species, which was more than three metres (10 feet) long and weighed about 600 kilograms (about 1,320 pounds), has been named Phiomicetus anubis.

"Egypt's environment ministry said in a statement Wednesday that the species of whale "was the most ferocious and ancient in Africa".

"'The whale had both the ability to walk on land and swim in the sea," it said, adding that the discovery was evidence of the evolution of whales from land mammals to marine mammals.

"'An anatomical study of the fossil shows that this new species of whale is completely different from other known species," the ministry said.

"It was a "large predator with large, powerful jaws" that allowed it to "control the environment in which it lived'".

Earlier findings:

https://phys.org/news/2019-12-newly-fossil-whale-intermediate-stage.html

"Protocetids are a group of early, semi-aquatic whales known from the middle of the Eocene, a geological epoch that began 56 million years ago and ended 33.9 million years ago. Protocetid remains have been found in Africa, Asia and the Americas.

"While modern whales are fully aquatic and use their tails to propel themselves through the water, most protocetids are thought to have been semi-aquatic and swam mainly with their limbs.

"In their PLOS ONE paper, Gingerich and his colleagues describe a new genus and species, Aegicetus gehennae, the first late-Eocene protocetid. Its body shape is similar to that of other ancient whales of its time, such as the famous Basilosaurus.

"The researchers suggest that an undulatory swimming style might represent a transitional stage between the foot-powered swimming of early whales and the tail-powered swimming of modern whales.

"'Early protocetid whales living 47 to 41 million years ago were foot-powered swimmers. Later, starting about 37 million years ago, whales became tail-powered swimmers," said Gingerich, a professor emeritus in the U-M Department of Earth and Environmental Sciences and curator emeritus at the U-M Museum of Paleontology.

"'This newly discovered fossil whale, Aegicetus, was intermediate in time and form and was transitional functionally in having the larger and more powerful vertebral column of a tail-powered swimmer," said Gingerich, who is also a professor emeritus of ecology and evolutionary biology and of anthropology."

Comment: a transitional form which does not require the later complex physiological changes necessary for full aquatic life.