*Mauisaurus* vs large pterosaurs

[don ohmes <d_ohmes@yahoo.com>]

Considering elasmosaurs, and taking Mauisaurus as the extreme example: if one 
takes the small steps of assuming an ability to control buoyancy, and a 
'breath-holding' capacity to be expected in a large aquatic animal, then the 
ability to 'tread water' w/ the long axis of the body oriented vertically, and 
the nose at the surface is a given. It is my admittedly 'seat-of-the-pants' 
opinion that their design is actually quite appropriate to such behavior. 
Further, propelling the main body upward until the entire neck is in the air is 
trivial. In Mauisaurus, this exercise would end w/ the head 12-15m above the 
water surface, assuming the main body did not breach. 

Thus, any pterosaur below that altitude would be well w/in reach of the mouth 
of a large elasmosaur. Assuming an ability to bend the neck 30 degrees in any 
direction, there is a large cone (approximately 12m in diameter, assuming a 10m 
neck) wherein 'adjustments' could be made at the end of a strike that begins w/ 
the nose at the water's surface. Even a flex of 15 degrees gives an approximate 
cone of 6m. Almost any contact w/ a pterosaur's wing could knock it out of the 
air, even if no grip was attained by elasmosaurid teeth. Large pterosaurs would 
logically be more vulnerable to this type of attack than smaller, being less 
maneuverable.

Further, an elasmosaur swimming below the surface in clear water could 
accelerate at a positive angle of 25 or 30 degrees relative to horizontal. 
Given a 15m neck, this would put the head approximately 10 m above the water 
surface when the main body breached the surface. Pterosaurs 'hover-fishing' 
into the wind might have a groundspeed near zero, and therefore would be quite 
vulnerable to cruising elasmosaurs. Any pterosaur actually sitting on the water 
would be a 'dead duck', of course.

Note that the largest pterosaurs and the largest elasmosaurs co-existed, and a 
'first-glance' seems to show a size correlation between the animals through 
time.

It is my opinion that the speculation that the long-necked plesiosaurs may have 
been adapted to be significant predators of marine volants generally, and large 
pterosaurs in particular, is justified. Even the relatively stiff neck would be 
advantageous. (Read "giant pterosaur-killing arrows"...)

I have never seen this seemingly obvious idea in print, though, nor heard it 
advanced in conversation. Does anyone have a reference to the contrary, 
rebuttal, criticism  or comment?

Don

Basic elasmosaur morphology taken from the Wikipedia (the source of first, not 
last resort) "Plesiosaur" article.