Taco Bell and its famous talking Chihuahua lost a dogfight at the Supreme Court Tuesday. 

The court, without comment, declined to get involved in a copyright battle over who came up with the idea for the fast-food chain spokesdog. 

Taco Bell had urged the court to throw out claims by two Michigan men that the Mexican food restaurants stole their idea for a talking Chihuahua. 

In a rare bit of whimsy amid the dry claims of copyright law, Taco Bell's lawyer, veteran Supreme Court litigator Carter Phillips, began his legal brief by noting, ``This is a tale of two dogs.'' 

The Michigan men claim they pitched the idea of using a cartoon Chihuahua to sell Taco Bell food more than a year before the company began airing its dog ads in 1997. 

The Taco Bell ads, since discontinued, featured a real Chihuahua who appeared to say in Spanish, ``Yo quiero Taco Bell,'' or, ``I want Taco Bell.'' The ad campaign became wildly popular, with spinoff stuffed toys, T-shirts and other products. 

Joseph Shields and Thomas Rinks allege Taco Bell advertising executives stole their idea for a character called ``Psycho Chihuahua'' after making a verbal agreement to use the men's design. 

Taco Bell claims the company decided to use a talking dog only after TBWA/Chiat Day, a much larger advertising company, proposed it independently. 

The men sued under state law in 1998, alleging Taco Bell breached its contract and wrongly made money from the ad campaign. A federal judge dismissed the case the following year after finding that federal copyright law trumped those state law claims. 

A federal appeals court reversed that decision last year, and reinstated the case. 

Taco Bell then appealed to the Supreme Court. 

Taco Bell owns or franchises thousands of Mexican-style restaurants worldwide from its base in Irvine, Calif. The company is a subsidiary of Tricon Global Restaurants, Inc., which also owns Pizza Hut and Kentucky Fried Chicken.