Until now, the whale series went something like this:
"Pakicetids (fully terrestrial): ~50 mya
Ambulocetids (semi-aquatic): 49 mya
Remingtonocetids (semi-aquatic): 49 mya
Rodhocetus (a Protocetid, semi-aquatic): 47 mya
Basilosaurids (fully aquatic): 40 mya"
So under the previous timeline, Darwinian biologists didn't have to worry about accounting for the origin of fully aquatic whales until about 40 mya. This new find pushes fully aquatic whales back to 49 mya. Now the timeline looks something like this:
"Pakicetids (fully terrestrial): ~50 mya
New Fossil Jawbone (fully aquatic whale): 49 mya
Ambulocetids (semi-aquatic): 49 mya
Remingtonocetids (semi-aquatic): 49 mya
Rodhocetus (a Protocetid, semi-aquatic): 47 mya
Basilosaurids (fully aquatic): 40 mya"
Discovery of "Oldest Fully Aquatic Whale" Fossil Throws a Major Bone into Whale Evolution Story - Evolution News & Views
look here, it literally went from a tiger to whale in 1 million years. next time one of you decide to put a cute chart make sure its not outdated, tigers to whales. Ha!