@neologist,
How do these Bible Thumping threads get turned into "erzats science". It appears you theumpees like to deny scientific discussions and like to hide your belief systems in a religious format. I find that kind of cowardly of you.
The "Migration of nostrils " in cetaceans is NOT a defining evidence associated with the evolutionary connections between Raoellid mammals and cetaceans. The "nostril " is more of a way to "track volutionary morphing"
The real associations are 4 areas that were first defined from a smattering of fossils in the late 1980's and pretty much evidenced by 2007. These areas include
1. Indohyus has a thick coating of bone in a medial space of its middle ear. This
structure, called an
involucrum (nasty word but hey, I didnt pick it, is UNIQUE to all the cetaceans and, little indohyus. All living whales have the involucrum , SO DID INDOHYUS.(There is a NAture article from 2007 that dicusses the structure and its function and its evolutionary track (via fossil bones)
2 Indohyus had a tooth structure unique to it and the early fossil species of whales (pakicetus, Indocetus etc). There was a familar pattern of dentition morphing that evidences a dietary change from vegetarian to meatatarianin about 1 15 my period. All dentition was developed as "fully whale like " (for toothed whales) by the time Basilosaurus was roaming the estuaries of mid Asia.
3Limb bone structure of Indohyus was unique to a whole bunch of water dwelling mammals. The limb bones had a sheath of dense heavy-weight coating of osteoapatite which is unique to ALL early whales, only toothed whales among the living species, todays seals, beavers, hippos and there is a developing sheath in polar bears. These are all animals adapted to aquatic living and the sheath keeps them from bobbing around.
4. O16/O18 ratios in Indohyus' fossil tooth enamel indicated that this critter was indeed aqautic It had toes with thick nails (actually mini-hoofs) on each digit and the digits were seen to morph into longer versions as that feature was a more successful adaptation in younger aged fossil Indohyuses.
AlsoRemember, theres a huge event beginning to occur in the neighborhood around the same time that the Indohyus lived there . In late Pangean times The area of the belly of Asia has a southern neighbor called the Cimmerian Terrain. This is separated by Tethys sea and along about 50 million years ago the entire area began closing (ie , moving the Cemmerian landscape towards the bowels of Asia) , where, by 30 my later, wed begin seeing the rising Himalayas.
Until that time, think of the area like the Atlantic Coast of US. It was a "trailing edge plate" that was loaded with shallow esturies and swamps. These would soon become deeper basins as Cemmeria started moving N at a rather fast rate (tectonically speaking) some say as fast as 10 cm 'year.
So here we see the developing ocean basins and entire oceanic shelves and fossil rich sedimentary beds appeared. Was this a force for transmutation of species?? Who the hell knows but, theres some real circumstantial evidence that relates these fossil species together.
One last thing is that the occurence of the stem species like indohyus and pakicetus etc ALL happened in this area of the earth.