Re: really weird idea about Ichthyosaurs

["Ralph Miller III" <gbabcock@best.com>]

Betty Cunningham <bettyc@flyinggoat.com> writes:
> What if Ichthyosaurs used their eyes to recieve sound vibrations instead
> of a melon? Perhaps not as true sound but as simple vibration info
> 
> -The eye is full of fluid (like a melon)
> -The eye is huge in nearly all cases-larger than Mosasaurs, Plesiosaurs,
> or Cetaceans.  Perhaps larger than needed for sight alone.
> -The eye is surrounded by very tiny bones that could transmit sound into
> vibration (like ear bones do)

As I understand it, a cetacean's sonar sound-emitting process begins within
the cranium, possibly in the air sac system of the head, and the sound
waves radiate forth in a narrow cone, from a concave bone surface at the
front of the skull, and through the lens we call the melon.  I am under the
impression that the sonar echo is then received through the mandible, which
transmits the vibrations to the inner ear.  To reconcile this data with
your analogy, you might instead propose that the ichthyosaur is _sending_
the sounds laterally out both eyeballs, but if such is the case, the
initial sound emission might function less effectively in pinpointing prey
than the forwardly-directed narrow beam of sound employed by extant
cetaceans.  I trust that list members will correct my description of
cetacean sonar technique if I am in error.

-- Ralph Miller III     gbabcock@best.com

Are we getting off-topic yet?