Re: Dinosaur whodunit: Solving a 77-million-year-old mystery

[Dann Pigdon <dannj@alphalink.com.au>]

Quoting David Marjanovic <david.marjanovic@gmx.at>:

> > Are eggs that must be turned periodically something unique to avians?
> 
> Yes. Crocodile eggs must _not_ be turned.
> 
> That makes it an interesting question what the intermediate looked like... 
> does someone know if lepidosaur, turtle or monotreme eggs can be turned? 

Lizard eggs can't be turned. When the eggs of lizards are collected in the 
wild, the researchers 
usually place a dot of ink on the upper-most part of the egg to make sure 
they're transported and 
incubated the same way up. I beleive the same is true of turtle eggs.

Monotremes only spend around 10-12 days in the egg before hatching, so perhaps 
they're not in 
there long enough for turning to matter. Playpus eggs are incubated outside of 
the pouch, while 
echidnas incubate their inside. I imagine that the rough-and-tumble lifestyle 
of an echidna means 
that their eggs are constantly jostled and tilted, so they can't be all that 
sensitive.

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Dann Pigdon
GIS / Archaeologist              http://geo_cities.com/dannsdinosaurs
Melbourne, Australia             http://heretichides.soffiles.com
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