[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Egg-Eating Teeth and Responses of Bois



  Just addressing a specific topic:

John Bois wrote:

<<<<In addition to size increase, dentition diversity
increases.>>>>

and Caitlin Kiernan wrote:

<<<Can you demonstarte a connection between more
complex mammalian teeth and ovivory?>>>

<<No.>>

<If specialized dentition cannot be demonstrated to be
specialized for ovivory, than don't site it as
evidence in your favor.>

  There is specialized dentition used to regard the
ability to crush objects for food. I think I posted on
this. It isn't _required_, but it isn't neccessarily
out of the picture. For instance, while the jaws of
both dicynodonts, oviraptorids, and placodonts have
apparent crushing adaptations (see Romer, 1966, for a
synopsis of all three) as Gans noted (1954) teeth are
not neccessary for crushing objects. Two groups, one
modern and one extinct, have teeth but with crushing
adaptations to the jaws and/or other anatomy.
Placodonts crush within their mouths, and the palatal,
maxillary, and dentary teeth are modified into
crushing plates, as do many dipnoans; on the other
hand, dasypeltids and some viperid snakes, teeth are
present, but not neccessarily used for the processing
of the objects; dicynodontian (read:
non-vjushkoviimorphan) dicynodonts lack teeth, as well
as oviraptorosaurs, but the crushing apparatus occurs
well forward in the alimentary canal, in snakes along
the canal before the stomach; placodonts and dipnoans
reflect oviraptorosaurs and dicynodonts in jaw
construction, but jaw _function_ in the last is more
or less unresolved (just read Hotton, 1994, and Sues
and Reisz, 1997, for general edentulousness
adaptations and refs. therein). I need to go find the
papers in my files of some of these, then I'll post a
biblio with synopsis.

-------

  Regarding tooth function in egg crushing, I am
presently working on what adaptations, in toothed
animals, might reflect ovivory or conchophagy. Most
small mammals have selenodont teeth (with an elongated
cusp), not suited for processing eggs or other shelled
foods, and so it is not so far determined to have an
effect on ovivory, and it is these animals that
consume most eggs in given ecology, which is further
evidence I will present soon.

  The remarks concerning varanid egg-consumption
related to teeth are void -- teeth are not involved in
the consumption of eggs in varanids, as demnstrated
from observing footage of *Varanus komodoensis* eating
eggs, and as a result, the teeth are simple,
piercing/tearing conodont/sub-ziphodont in morphology;
they do in fact have jaws (the acquisitive apparatus)
larger than the consumed object -- this results in a
lack of need for teeth in consuming the egg. It has
been further shown that in consuming objects smaller
than the jaws, or in attacking objects smaller than
the jaws, the teeth are not primarily used in assault
in both varanids and in boid snakes -- again, I'll get
the refs in a later post.

  I would appreciate helpfull and critical comments
and references to further data that would elucidate
remarks made on the matter, not just my own. I'm also
looking into localized ecologies to find egg-eating
and its broader effects, so help in finding specific
cases would be very well appreciated.

=====
Jaime "James" A. Headden

"Come the path that leads us to our fortune."

Qilong---is temporarily out of service.
Check back soon.

__________________________________________________
Do You Yahoo!?
Kick off your party with Yahoo! Invites.
http://invites.yahoo.com/