One of the facts about evolution that really blew my mind when I first learned about it was that whales had evolved from land mammals that had returned to the sea. Even though I had no formal training in biology beyond eighth grade, I was aware of course of the basic evolution story of how we all evolved from ocean organisms but the idea that at some point the process got reversed for some branches of the evolutionary tree and they become sea-dwelling creatures again just captured my imagination and I have posted about it before.
This animation shows how a reconstruction, based on the fossil record, of how it happened.
So I am always interested in new developments in this area and now comes along a report of the fossil of a new species of four-legged whales that weighed about 600kg and three meters (10ft) in length that was found in Egypt’s Western desert and lived around 43 million years ago.
The partial skeleton was found in Egypt’s Fayum Depression and analysed by scientists at Mansoura University. Although the area is now desert, it was once covered by sea and is a rich source of fossils.
“Phiomicetus anubis is a key new whale species, and a critical discovery for Egyptian and African palaeontology,” the study’s lead author, Abdullah Gohar, told Reuters news agency.
While this is not the first time the fossil of a whale with legs has been found, the Phiomicetus anubis is believed to be the earliest type of semi-aquatic whale to be discovered in Africa.
The first whales are thought to have first evolved in South Asia around 50 million years ago. In 2011, a team of palaeontologists in Peru discovered a 43-million-year-old whale fossil with four legs, webbed feet and hooves.
You can read the paper here.
It is such an amazing thing to consider. I feel sorry for all those evolution deniers who will never feel the sense of wonder that I feel when I think of how simple laws of science can produce such a complex array of organisms.