What was the critical factor causing the official separation between the Miniature Fox Terrier and the Tenterfield Terrier lines?
Answer
Official recognition status by the Australian National Kennel Council (ANKC)
The critical point of separation stemmed from the ANKC's stance; they would not accept the name 'Miniature Fox Terrier,' prompting ANKC-aligned breeders to adopt the name Tenterfield Terrier.

Related Questions
What was the critical factor causing the official separation between the Miniature Fox Terrier and the Tenterfield Terrier lines?Which registry did breeders who wished to retain the historical name 'Miniature Fox Terrier' establish?Which color pattern is explicitly accepted in the Tenterfield Terrier standard but strictly disallowed for Miniature Fox Terriers?What concrete structural difference relates to foot shape between the two breeds?What specific health condition is noted as being actively managed by dedicated Tenterfield Terrier breeders?What was the likely ancestral cross used in the Miniature Fox Terrier lineage to enhance speed and agility?What is indicated about the general financial cost comparison between the two breeds?For which reason was the name Tenterfield Terrier partially selected?What vital care aspect is mentioned specifically when discussing the Tenterfield Terrier's foot structure post-walks?What key aspect of lifestyle must be satisfied for both intelligent breeds to prevent boredom and destructive behavior?