STATO-ACOUSTIC ORGAN and cochlea

[Kevin Austin <kevin.austin@xxxxxxxxxxxx>]

I am reading on: SENSORY ORGANS: STATO-ACOUSTIC ORGAN
http://aquaticpath.umd.edu/fhm/ear.html

Is the term "lateral organ' an oversimplification of a 
multi-dimensional process for the transduction of vibration / 
pressure waves / positional information?

The article notes:

  Like semicircular canals, otolith chambers are
  lined with squamous epithelium and filled with
  endolymph. Maculae are flattened on the ventral
  surface of the chambers above which (and in
  contact with the sensory cell hairs) are
  suspended the otoliths.

This sounds like a version of the cochlea, and I read that the 
cochlea and the canals share the same endolymph, all being part of 
the labyrinth. And for some evolutionary reason, the endolymph has 
potassium as the depolarizing agent of the hair cells, possibly 
because of the increased electrical gradient provided?

http://en.wikipedia.org/wiki/Endolymph

Could someone point me to an article that would answer my question; 
Is the cochlea the evolutionary end of the lateral organ?

Thanks


Kevin