Whale of a time: Artist's conception of a male Maiacetus innus as it would have appeared in life.
Credit: John Klausmeyer, University of Michigan Museums of Natural History
Although the hind limbs would have been capable of bearing the weight of the animals body on land, said Gingerich, the proportions of its limbs to its toes would have made walking difficult, preventing Maiacetus from venturing too far from shore.
Like other early whales it fed at sea coming ashore to rest, mate and give birth, said Gingerich. "They were clearly tied to the shore… they were living on the land-sea interface and going back and forth."
Compared to known fossil whales, Maiacetus occupies a more intermediate stage in the transition between land and sea dwelling. It offers invaluable new information on structural and behavioural changes that accompanied that transition, said the researchers.
Beautiful transition
"Whale evolution was already one of the best documented evolutionary transitions in the fossil record. This adds another beautiful step in the ladder" said Hans Thewissen, an evolutionary biologist at the Northeastern Ohio Universities in Rootstown, USA.
"All this is rather amazing fifteen years ago, none of these transitional whales where known from skeletons, and creationists were making fun of scientists for claiming whales were derived from land mammals because there was not a single fossil showing that," added Thewissen, who was not involved in the study.
Specimens this complete are a virtual "Rosetta Stone," said Gingerich. "They provide insight into the functional capabilities and life history of extinct animals that cannot be gained any other way."
