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

Re: Meter-wide "dinosaur" eggs reportedly found in Chechnya



Would these considerations apply only to hard-shelled eggs that had to fit in 
the oviduct and pass through the pelvic girdle? Would a flexible-shelled, 
elongate egg (say) have been bound by different size constraints (though a soft 
shell might tear more easily on a heavier egg)?

Ronald Orenstein 
1825 Shady Creek Court
Mississauga, ON
Canada L5L 3W2

On 2012-04-15, at 9:39 PM, Tim Williams <tijawi@gmail.com> wrote:

> Mike Taylor <mike@indexdata.com> wrote:
> 
>> Alexander (1989:156-157) touches on this in The Dynamics of Dinosaurs
>> and Other Giants.  He doesn't give a number or even a range for the
>> size limit due to respiration issues, but does say "even elephant
>> birds were probably a long way from that limit".  (At 30 cm in length,
>> they are the largest known eggs.)  He also suggests that elephant-bird
>> eggs may be near a different limit, in that the shells of eggs much
>> larger would have been too thick for the chicks to hatch, but no
>> numbers are given.
> 
> 
> 
> Maximum egg size is also offered as a possible reason why the enormous
> Australian dromornithids (such as _Dromornis_) didn't get even bigger.
> Either that, or a larger body mass was limited by metabolic
> constraints, specifically the need to support an elevated, avian-level
> metabolism based on low-energy browse.  Both these reasons appear in
> the "Magnificent Mihirungs", as possible explanations for why
> dromornithids (mihirungs) lost out to large marsupials like the
> diprotodontids that were able to surpass the dromornithids in mass.
> 
> 
> 
>> No doubt others have looked into this in greater detail, but sadly
>> Alexander gives no references.
> 
> 
> 
> I've yet to find a reference.  Not one that provides quantitative data, 
> anyway.
> 
> 
> 
> 
> 
> 
> 
> Cheers
> 
> Tim