Re: Leaellynasaura, Tails, and Integument

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

On Tue, Jul 13th, 2010 at 4:39 AM, Jocelyn Falconnet <j.falconnet@gmail.com> 
wrote:

> "Dorsoventral and cranial expansion of
> postzygapophyses (up to 44% of vertebral body length) on vertebrae in
> the terminal half of the tail of L. amicagraphica suggests an
> alternative to ossified tendons to provide caudal axial rigidity."

> As far as I understand, the caudal vertebrae of *Leaellynasaura*
> exhibits several anatomical features seemingly related to the
> stiffening of the tail, analogous to the adaptations seen in the
> classical theropod and ornithischian examples. Pretty interesting
> example of convergent evolution and functional evolution.

My question is: would such a stiffening system restrict lateral movement of the 
tail? If the stiffening 
was mainly to hold the tail erect, then perhaps it only had to prevent it from 
bending in the sagittal 
plane. That might leave enough lateral flexibility to curl the tail about the 
body - or at least to allow 
the animal to turn around inside a burrow.

Then again, if the stiffening was mainly present in the terminal half of the 
tail, might the base of 
the tail be flexible enough for a cute little Leaellynasaura to tuck it's 
sleepy head and neck under it 
in a suitably adorable fashion?

-- 
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Dann Pigdon
Spatial Data Analyst               Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj
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