in actionScript
add
[RemoteClass(alias='br.moss.air.model.AnimalDimension')]
[Bindable]

where br.moss.air.model.AnimalDimension is the name of your class as
defined in
rubyamf_config.rb

as for exemple:
ClassMappings.register(
  :actionscript => 'br.moss.air.model.AnimalDimension',
  :ruby => 'AnimalDimension',
  :type => 'active_record',
  :attributes => ["id", "raca", "especie", "sexo"])

[]s
Bhola