Re: plesiosaur propulsion

[Scott <HORTON@BCRSSU.AGR.CA>]

>>  Sea creatures bend their bodies back and
>> forth, propelling themselves through the water.  Did plesiosaurs do a
>> similar motion? 

>No.  They paddled like a sea turtle.

>> Or, were they not concerned with speedily moving their bodies
>> through the water, floating slowly about like manatees, but darting their
>> heads here and there for food?

>More or less.  I would say they were faster and more active than
>manatees, but they were definately not speed chasers.
>swf@elsegundoca.ncr.com                sarima@netcom.com

  Rather than using their paddles like the oars of a rowboat, a new study that
I just heard of suggests that the paddles were moved vertically up and down to
function like underwater wings. It is claimed that this could provide high
speed propulsion for plesiosaurs. Maybe the nearest modern equivalent might be
a penguin?
  This is not my idea and I myself am a little bit skeptical.
  Some plesiosaurs had tails long enough to provide propulsive force, some
didn't. Certainly a long neck makes catching fish easier without requiring
fast body speed. I always thought that a plesiosaur would be too slow to escape
a predator (mosasaurs?), though.

Scott Horton
Geophysicist/Computer Programmer