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RE: dino-lice

  I would like to note that no animal eats eggs of any sort exclusively, up to 
and including the African egg-eating snake, *Dasypeltis* spp.; their diet also 
includes various lizards, small, small mammals and even other snakes. Virtually 
all snakes are opportunistic carnivores. Egg-eating as a specialization, 
however, does seem to drive morphology into a unique series of cranial, 
vertebral and muscular adaptations. *Oligodon* spp., the kukrisnakes, also 
possess specialized, broad rear-fanged teeth which adapt them to slicing open 
eggs (or really, anything else they bite) rather than simply puncturing.


Jaime A. Headden
The Bite Stuff (site v2)

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 

> Date: Thu, 21 Apr 2011 22:19:01 -0700
> From: ron.orenstein@rogers.com
> To: augustoharo@gmail.com
> CC: dinosaur@usc.edu
> Subject: Re: dino-lice
> In tropical humid forests many species of birds breed over a good part of the
> year, with breeding recorded in every month, so egg-eaters could find nests
> throughout the year. However, with the exception of African egg-eating snakes 
> I
> cannot think of any vertebrate that eats eggs exclusively; most nest-robbers 
> are
> pretty opportunistic.
> Ronald Orenstein
> 1825 Shady Creek Court
> Mississauga, ON L5L 3W2
> Canada
> ronorenstein.blogspot.com
> ----- Original Message ----
> From: Augusto Haro 
> To: Ronald Orenstein 
> Cc: Dinosaur Mailing List 
> Sent: Fri, April 22, 2011 12:51:38 PM
> Subject: Re: dino-lice
> 2011/4/22 Ronald Orenstein :
> > A snail-picking adaptation might have led to a digit such as those in
> > alvarezsaurs, but why would the other digits be lost (they might be useful 
> > in
> > picking the animal out of the shell, for example)?
> May be, but I was thinking perhaps just a hook is optimal for
> snail-hooking, and that a similar development of other fingers may
> obstaculize it.
> > And why would such a
> > strongly-muscled arm be required?
> I think the forearm is strong relative to the size of the forearm, not
> so much relative to the size of the entire animal. Perhaps no more
> than in coelurosaurs with longer limbs. Before I wrote (but think it
> did not reach the list), that, so to speak, you choose the size of the
> pincer according to what do you want to pick. You would not use a
> pincer used to remove nails to extract a barely visible splint from
> your skin. So, perhaps if you want to break large termitaria, you use
> a large, strong forelimb, as in anteaters, pangolins, giant armadillo,
> etc. If you need to break something small, you may more economically
> use a smaller version of this. If you need to partially break a small
> thing (I was favouring perforating eggs for the thin snout to enter
> the hole, and to avoid its contents oozing), you need greater
> precision and this is given by a small version ot the same principle.
> For example, a large knife may be useful to get slices of a large
> vegetable, but may crush a small vegetable, where slices may be better
> made with a small knife.
> By the way, a question to you, which are an ornithologist: Do all
> birds deposit their eggs in the same season of the year in a given
> place? Because if this is true, then egg-eating (my favourite
> hypothesis) would not be so easy the rest of the year...
> > If the arms were used in foraging it seems more likely that they would have
> >been used as levers against considerable force
> > -- perhaps pulling apart some tangled mass of plant fibres or ripping into a
> > cycad trunk, for instance -- if they had access to some sort of trunked or
> > otherwise erect plant the difficulty of them having to stoop to ground level
> >to
> > burrow might not exist. Could the arms of alvarezsaurs be analogous to the
> > enlarged rooting teeth or tusks of some herbivorous mammals - given that 
> > tooth
> > modification was not on the cards for them - rather than to any limb 
> > structure
> > in another animal?
> These are possibilities... Indeed, they may not be mutually exclusive,
> because many structures can give many good uses, and perhaps looking
> for the one which was selected for implies dismissing the possibility
> that having something good for many uses, instead of specialized for
> the best performance at a unique task, in itself was something to be
> selected for.