Transitional Whale Species Hunted at Sea, Gave Birth on Land
by Brandon Keim
Early whales hunted at sea but spent the rest of their time on land, suggest two newly-described fossil whales — one of them a pregnant female — believed to represent a transitional species between earth- and water-bound behemoths.
Dating from 47.5 million years ago, the whales had large teeth suited for consuming fish, and flipper-like limbs that could support their weight on land, albeit awkwardly. The fetal skeleton was positioned for head-first delivery, typically seen in land mammals. Modern whales give birth tail-first.
“They clearly were tied to the shore,” said study co-author Philip Gingerich, a University of Michigan paleontologist, in a press release. “They were living at the land-sea interface and going back and forth.” Gingerich’s team dubbed the whales Maiacetus inuus. Maicetus means “mother whale,” and Inuus was a Roman fertility god…
(read more: Wired Science)
Citation: “New Protocetid Whale from the Middle Eocene of Pakistan: Birth on Land, Precocial Development, and Sexual Dimorphism.” By Philip D. Gingerich, Munir ul-Haq, Wighart von Koenigswald, William J. Sanders, B. Holly Smith and Iyad S. Zalmout. Public Library of Science ONE, Vol. 4 No. 2, Feb. 3, 2009.
Image: Maternal M. inuus skeleton, with fetal whale in blue / PLoS ONE