We are informed in this New Scientist article that “Early birds may have dropped teeth to get airborne.” (Colin Barras, 08 December 2009)
If true, it would be no surprise. It’s the same reason airports impose luggage weight restrictions on passengers. Not clear why this is even a story. Apparently, four extinct groups of birds all lost their teeth independently.
That theory is “as good as any other”, says Mike Benton at the University of Bristol, UK, though he remains sceptical. “Losing teeth wouldn’t make a huge difference to balance in the air.”
Essentially, the big problem for birds isn’t losing their teeth, it is replacing them. The birds needed a whole digestive system that substitutes small stones and grit, swallowed into the “crop”, and the behaviour pattern of seeking them out and swallowing them.
I wonder how all that would happen by a multitude of slow Darwinian steps before they starved to death?
There’s got to be more to this. Why did all four known groups lose their teeth without exception? (Journal reference: Proceedings of the Royal Society B, DOI: 10.1098/rspb.2009.0885)
(Note: It’s coffee time. Cartoon birds do have teeth. Here are some images. It’s interesting that, when making a bird think and talk like a human, the cartoonist cannot resist adding teeth.)