diff --git a/app/models/taxon.rb b/app/models/taxon.rb
index cc2757dd053..4aa673ba383 100644
--- a/app/models/taxon.rb
+++ b/app/models/taxon.rb
@@ -67,6 +67,9 @@ class Taxon < ActiveRecord::Base
                           :unless => Proc.new { |taxon| (taxon.parent_id.nil? || !taxon.is_active)},
                           :message => "already used as a child of this " + 
                                       "taxon's parent"
+  validates_uniqueness_of :source_identifier,
+                          :scope => [:source_id],
+                          :message => "already exists"
   
   NAME_PROVIDER_TITLES = {
     'ColNameProvider' => 'Catalogue of Life',
@@ -523,6 +526,7 @@ def set_scientific_taxon_name
         :source => source,
         :source_identifier => source_identifier,
         :source_url => source_url,
+        :name_provider => name_provider,
         :lexicon => TaxonName::LEXICONS[:SCIENTIFIC_NAMES],
         :is_valid => true
       )
diff --git a/app/models/taxon_name.rb b/app/models/taxon_name.rb
index 4dae91977e7..4f941e8c3f3 100644
--- a/app/models/taxon_name.rb
+++ b/app/models/taxon_name.rb
@@ -10,6 +10,10 @@ class TaxonName < ActiveRecord::Base
                           :scope => [:lexicon, :taxon_id], 
                           :message => "already exists for this taxon in this lexicon",
                           :case_sensitive => false
+  validates_uniqueness_of :source_identifier,
+                          :scope => [:source_id],
+                          :message => "already exists"
+
   #TODO is the validates uniqueness correct?  Allows duplicate TaxonNames to be created with same 
   #source_url but different taxon_ids
   before_validation :strip_tags, :strip_name, :remove_rank_from_name, :normalize_lexicon
diff --git a/vendor/plugins/ratatosk/lib/ratatosk/name_providers/nzor.rb b/vendor/plugins/ratatosk/lib/ratatosk/name_providers/nzor.rb
index f2d2a097fda..6035dbaf7ff 100644
--- a/vendor/plugins/ratatosk/lib/ratatosk/name_providers/nzor.rb
+++ b/vendor/plugins/ratatosk/lib/ratatosk/name_providers/nzor.rb
@@ -163,8 +163,14 @@ class NZORTaxonAdapter
       # Initialize with a Nokogiri object of a single CoL XML response
       #
       def initialize(hxml, params = {})
-        @adaptee = Taxon.new(params)
         @hxml = hxml
+        existing = Taxon.find(:first, :conditions => {:source_id => Source.find_by_title('New Zealand Organisms Register').id, :source_identifier => @hxml.at('NameId').inner_text})
+        @adaptee = if existing.present?
+          existing
+        else
+          Taxon.new(params)
+        end
+
         @adaptee.name               = @hxml.at('PartialName').inner_text
         @adaptee.rank               = @hxml.at('Rank').inner_text.downcase
         @adaptee.source             = Source.find_by_title('New Zealand Organisms Register')