[crpntr@ix.netcom.com: Re: Walking with dinosaurs]

[Mickey Rowe <rowe@psych.ucsb.edu>]

On Tue, 18 Apr 2000 19:24:34 -0400 (EDT) John Bois
<jbois@umd5.umd.edu> had the audacity to write:

> My leader, Mickey Rowe,

For the record, I have not lead John anywhere.  I haven't even been to
most of the places he goes!

But more importantly he also wrote:

> we can visualize nest predation where gape is not an issue.  [...]
> gape is subject to misconception even by the wisest of researchers.
> For example, Kenneth Carpenter, in his otherwise fantastic book (a
> must read, in my view) cannot consider mammals as a potential cause
> of extinction because, "(considering) the small size of their
> mouths, it seems doubtful that any of these could have cracked open
> a dinosaur egg."

I forwarded John's comments to Ken who responds:

------- Start of forwarded message -------

  Thanks for the kind words on my book. Regarding the mouth size, you
  must understand that MOST carnivorous mammals were the size of a
  shrew, hence would barely be able to get their mouth around your
  pinky. In addition, the teeth are all very high cusped, as in a
  shrew, and indicate a diet of insects. A shrew-size mammal cannot
  push a navel orange-size egg (the average size of dinosaur eggs)
  against another to break it open, let alone get its mouth around
  it. However, Gobicodon and Didelphodon, cat-size, could easily crack
  open snaller eggs or ends of eggs in their mouth (e.g., the end of a
  Elongatoolithus egg). I don't think that rolling eggs together to
  break them open was a very important strategy because dinosaurs
  apparently buried their eggs. Ostrich eggs that get broken by
  banging against another are laid in the open where there is no
  constraining earth to keep the eggs from rolling. That then leaves
  only the mouth as a way of breaking open an egg. Don't forget, I
  also mentioned that many dinosaur eggs show the tops caved in. In a
  clutch, all the eggs are broken at the top, implying that they were
  buried so that the eggs could not roll around as they were being
  broken. See Bertram's book on ostriches. He shows a wild dog eating
  an ostrich egg - the opening is on the side because the egg was
  rolled over so as to make it easier for the dog to feed. I hope you
  all enjoyed the baby sauropods in WWD. See you all at the
  Discovery.com discussion forum.

  Kenneth Carpenter, Ph.D.
  Fossil Lab, Dept. of Earth Sciences
  Denver Museum of Natural History
  2001 Colorado Blvd.
  Denver, CO 80205

  phone (303)370-6392 fax (303)331-6492

  email: KCarpenter@DMNH.org 
         Crpntr@ix.netcom.com
------- End of forwarded message -------

-- 
Mickey Rowe     (rowe@psych.ucsb.edu)