So I started reading this blog called MAIACETUS...

After much deliberation and input from friends and family I finally chose MAIACETUS for my blog name so I figure I should start by telling you about MAIACETUS. I chose MAIACETUS because it's a new term relevant to the world of marine mammal science. It's also a safer choice than some of the other, more entertaining & daring names I'd chosen (The Blowhole, The Fluke Files!) and I think it sounds cool.

So what is MAIACETUS and, on that note, how does one pronounce it?

First let’s start with the easy stuff…pronunciation! If you’re not a science/biology/latin nerd you might want to say MY-AH-KEETUS or MAH-EEE-AAAH-SEEET-US or MAH-EEE-AAAH-KET-US or the myriad variety of other pronunciation possibilities. I decided to check out the dictionary pronunciation for MAIA- and -CETUS and, according to the American Heritage pronunciation key, MAIA can be pronounced either mā'ə, mī'ə and CETUS is pronounced sē'təs. In other words say either:

MAY-UH-SEE-TUS or MY-UH-SEE-TUS

And that’s it, simple as that :-)

Now, what exactly is MAIACETUS? It’s an exciting paleontological discovery!

In 2000, a 47.5 million-year-old fossil was discovered in Pakistan by a research team led by University of Michigan palaeontologist, Philip Gingerich. Upon discovering the fossil the team realized they found the skeleton of a female whale and her fetus…the first discovery of a fetal skeleton in the taxonomic Group Archaeoceti, the group of whales believed to give rise to modern cetaceans (whales and dolphins)! The new species was called Maiacetus inuus; MAIACETUS means MOTHERWHALE and INUUS is the name of a Roman fertility god.

Adult female and fetal skeletons (type) of the protocetid Maiacetus inuus. Beige is female skull, blue is fetal skeleton

Source: Gingerich et al., 2009

Then in 2004, an 8.5 foot-long male specimen was collected from the same fossil beds. It had similar anatomical features to the female specimen but this skeleton, the most complete known Protocetid skeleton (the taxonomic Family which Maiacetus belonged to in the Group Archaeocetes), was 12% larger and had 20% larger canine teeth or fangs. This difference in sex sizes (known as sexual dimorphism) is not uncommon in whales and helps scientists understand social structure. The size difference in MAIACETUS was moderate (when compared to other sexually dimorphic species) suggesting that males didn’t control territories or harems of females.

As well, MAIACETUS’ teeth were BIG…this meant they were able to catch and eat fish so probably made their living at sea. Thus, according to Gingerich, MAIACETUS species made their living in the sea but came to land to rest, mate and give birth.

Skeleton of Maiacetus inuus (GSP-UM 3551, male)

Source: Gingerich et al., 2009

So, what is so important about these findings? MAIACETUS is a specimen representing the important transitional phase in whale evolution…the move from land back to sea. Hence, these fossils are valuable because they offer new information on the structural and behavioural changes that occurred as whales evolved from land dwelling to fully aquatic mammals.

For more information on MAIACETUS and whale evolution check out…

The Journal Article by Gingerich et al., at PloS ONE
The Amphibious Ancestors of Whales

Maiacetus Inuus - Fossils of Whales Reveal They Gave Birth On Land

Maiacetus, The Good Mother Whale