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RE: Protoceratopsoid tails adapted for swimming



Not to mention that it is not merely tall neural spines with some inclination 
that matters here, but the position of the increasing height (towards the 
distal end) and the attachment for the lateral muscles of the tail extending 
significantly down the tail. Oviriaptorosaurs have such a latter quality, and 
this has been linked their high mobility (Persons et al., Persons & Currie, 
recent papers on tail mobility), while this quality isn't true in 
protoceratopsids. If the condition in protoceratopsids were true, despite the 
absence of ossified ligaments, hadrosaurs would have the same sculling quality; 
and indeed, this was argued in the past, despite being demonstrably untrue.

Cheers,

  Jaime A. Headden
  The Bite Stuff (site v2)
  http://qilong.wordpress.com/

"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 
Backs)


----------------------------------------
> Date: Tue, 3 Dec 2013 23:18:42 -0500
> From: ruben@mrbrklyn.com
> To: DINOSAUR@usc.edu
> CC: dinosaur@usc.edu
> Subject: Re: Protoceratopsoid tails adapted for swimming
>
> On 12/03/2013 10:40 PM, Ben Creisler wrote:
>> From: Ben Creisler
>> bcreisler@gmail.com
>>
>>
>> A recent paper not yet mentioned on the DML:
>>
>> V. S. Tereschenko & T. Singer (2013)
>> Structural features of neural spines of the caudal vertebrae of
>> protoceratopoids (Ornithischia: Neoceratopsia).
>> Paleontological Journal 47(6): 618-630
>> DOI: 10.1134/S0031030113060105
>> http://link.springer.com/article/10.1134/S0031030113060105
>>
>>
>>
>> The structure of caudal neural spines of protoceratopoids displays
>> adaptation for aquatic and terrestrial mode of life. The increasing
>> height of caudal neural spines in the series Leptoceratops,
>> Udanoceratops, Protoceratops, Bagaceratops i
>> extent of adaptation for swimming and changes in inclination of neural
>> spines are connected with the mechanical balance of the lever. Thus,
>> the anterior caudal vertebrae (1cd–15cd) of Protoceratops and
>> Bagaceratops show an anticliny, which promotes extension (rise) of a
>> heavy tail in terrestrial conditions. In the middle part of the tail
>> (16cd–23cd), with the greatest height of neural spines, a decrease in
>> width and increase in thickness counteract transverse loads
>> accompanying movements on land. At the same time, the supraspinal
>> ligament prevents divergence of neural spines caused by curvature of
>> the tail as it is raised above the ground.
>>
>>
>
>
> I'm not buying it. You don't swim with a heavy boney collar wrapped
> around your neck and head. You go Kurplunt and drown.
>
> Ruben