Re: KT boundry event: why do bats have teeth if birds don't?

UC wrote:

John Harshman wrote:

UC wrote:

By the way, why do bats have teeth?

The better to eat bugs with, my dear? Is that a serious question about
adaptive evolution, or some rhetorical gambit? If it's a serious
question, we could all speculate, and I will if you like.

Well, since bats occupy in many cases similar niches to birds, why did
birds lose their teeth and bats retain theirs? Why no convergence?

Happy to speculate. I think it has to do with necks. Birds, like other
theropods, have long necks. Bats, like other mammals, have short necks.
(Even giraffes have short necks if we go be a count of vertebrae.
Mammals have 7, birds averaging around 12.) Birds end up using their
long necks and the heads on the end of them as primary manipulative
tools, so are not inclined to give up the necks.

The point of tooth loss is not to save weight per se, but to
redistribute it more toward the center of gravity, which helps keep them
more maneuverable in flight. Which explains why many birds, lacking
teeth, swallow rocks that are just as heavy as a mouthful of teeth would
have been. No weight saving, but a useful redistribution.

Bats, on the other hand, with their short necks, have less problems with
center of gravity, and can afford more easily to retain the teeth.

Another point is that mammals, unlike most other carnivorous or
insectivorous tetrapods, heavily process their food in their mouths;
i.e., they chew. This saves some effort and space in the digestive
system, which losing the teeth would require compensating for. Toothed
birds and other theropods, on the other hand, used their teeth only for
grasping prey before swallowing it whole, a much less important and more
easily replaced function.

.

Relevant Pages

  • Re: Out Of Africa Or Eternity?
    ... All modern birds have all the DNA for a complete set of teeth. ...
    (talk.origins)
  • Re: KT boundry event
    ... I don't know if it is proper to use the modern terms to refer to them. ... Cretaceous there were already several kinds of birds. ... species were small and probably ate insects and spiders. ... Odontornithes, or BIRDS with teeth. ...
    (talk.origins)
  • Re: KT boundry event
    ... Odontornithes, or BIRDS with teeth. ... The correct plural is "platypodes". ... than you who doesn't consider them mammals? ...
    (talk.origins)
  • News: Mega-bird had a five-metre wingspan... and teeth
    ... PARIS (AFP) - A bird that swooped over the waters covering what is now ... to tip and had bony teeth with which to grab its food, ... Gerald Mayr of Germany's Senckenberg Research Institute said Dasornis ... now-extinct giant birds called Pelagornithids. ...
    (talk.origins)
  • Re: The REAL problem with science
    ... Among the smarter birds, parrots may be self-aware. ... New research shows that magpies can recognise themselves - the first ... the ability to recognise oneself in a mirror develops ... The feel of the mark on their necks did not seem to alarm them. ...
    (talk.origins)