Wednesday, February 4, 2009

Darwin Day Special: Discovery of new transitional fossil of whales announced

Boy oh boy, give me a little free time and look at all the posts I can publish! I'll leave the news about the giant fossil snake, Titanaboa cerrejonensis, for you to find on your own by the way.

Philip Gingerich and colleagues have just published an article describing fossils of whale ancestors they discovered in Pakistan. They found two adults, one male and one female, and as they uncovered the fossil of the female whale they discovered a fetus inside. These early whale ancestors still had legs, and most likely gave birth on land.

The fetus had teeth and was facing head first toward the birth canal which is why the researchers believe the animals gave birth on land. As you can imagine, heading into the water head first to take one’s first gulp of air would be disastrous for the baby. Modern whales are born tail first.

The well formed teeth suggest the young were very precocious, and ready to feed soon after birth.

The name of this 45 million year old ancestral whale fossil is Maiacetus inuus. You can read the article by Gingerich and colleagues here as well as see photos and drawings of the fossils.

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