An artist’s impression of Basilosaurus isis. Image credit: Pavel Riha / CC BY-SA 3.0.
SciNews has a story about a recently discovered whale from the Eocene of Egypt. Called Aegicetus gehennae, this ancient mammal give important clues in the evolution of whale locomotion. A team of paleontologists, including Professor Philip Gingerich of the University of Michigan, published the details in a recent paper in the journal PLoS ONE.
Protocetidae (protocetids) are a group of semi-aquatic whales known from the middle Eocene epoch of Africa, Asia, North America, and South America.
While living whales use their tails to propel themselves through the water, most protocetids were foot-powered swimmers.
The newly-discovered protocetid, Aegicetus gehennae, was more fully aquatic and less specialized as a foot-powered swimmer than earlier protocetids.
It represents a transitional stage between the foot-powered swimming of early whales and the tail-powered swimming of living whales.
“It is the youngest-known protocetid, dating to around 35 million years ago, and is known from one exceptionally complete skeleton and a partial second specimen, making it among the best-preserved ancient whales,” explained University of Michigan’s Professor Philip Gingerich and colleagues.
Aegicetus gehennae had an estimated body mass of about 900 kg, according to the team.
“Compared with earlier whales, it has a more elongated body and tail, smaller back legs, and lacks a firm connection between the hind legs and the spinal column,” the researchers said.
