Question: Which is extinct, Blue Paul Terrier or Russo-European Laika?
Context: The Chamuco (a Mexican word which means "devil") or Mexican Pitbull is a dog breed not recognized by any Canofile association.  It originated in the center of Mexico, it was developed in this country in the 1970s, product of the accidental or intentional crosses of the American Pit Bull Terrier with the now extinct Mexican Bulldog, street dogs, American Bully, Pitbull Blue, Staffordshire bull terrier, American Staffordshire Terrier, and probably with the Boxer.  Its name comes from the Mexican slang "Chamuco", which means devil because of its temperament and tenacity.  Also it called Mexican pitbull or miniature pitbull, but actually is Dogo of Mexican origin. The Paisley Terrier was a breed of terrier type dog that is now extinct.  Originating in Scotland, the Paisley Terrier was bred primarily as a pet and showdog version of the Skye Terrier, and was the progenitor of today's Yorkshire Terrier.  The breed was called the Paisley terrier since most of the dogs came from that location, but it was also called the Clydesdale Terrier, for another location in the Clyde Valley where the dogs were bred. A Feist is a small hunting dog, descended from the terriers brought over to the United States by English miners and other working class immigrants.  These terriers probably included crosses between the Smooth Fox Terrier, the Manchester Terrier and the now extinct English White Terrier.  These dogs were used as ratters, and gambling on their prowess in killing rats was a favorite hobby of their owners.  Some of these dogs have been crossed with Whippets or Italian Greyhounds (for speed) and Beagles (for hunting ability) - extending the family to include a larger variety of purpose than the original ratter, or Rat Terrier. The Airedale Terrier (often shortened to "Airedale"), also called Bingley Terrier and Waterside Terrier, is a dog breed of the terrier type that originated in the valley ("dale") of the River Aire, in the West Riding of Yorkshire, England.  It is traditionally called the "King of Terriers" because it is the largest of the terrier breeds.  The Airedale was bred from the Old English Black and Tan Terrier (now extinct), the Bull Terrier, the Otterhound and probably some other Terrier breeds, originally to serve as an all around working farm dog.  In Britain this breed has also been used as a war dog, guide dog and police dog.  In the United States, this breed has been used to hunt big game, upland birds, and water fowl, and serve in many other working capacities. Russo-European Laika (Russko-Evropeĭskaya Láĭka) is the name of a breed of hunting dog that originated in the forested region of northern Europe and Russia, one of several breeds developed from landrace Laika dogs of very ancient Spitz type.  The "Russo-European Laika" itself dates to a breeding program begun in 1944 by E. I. Shereshevsky of the All-Union Research Institute for the Hunting Industry, in Kalinin (now Tver) Province. Blue Paul Terrier is an extinct breed of dog. The Kerry Blue Terrier (also known as the Irish Blue Terrier) () is a breed of dog.  Originally bred to control "vermin" including rats, rabbits, badgers, foxes, otters and hares, over time the Kerry became a general working dog used for a variety of jobs including herding cattle and sheep, and as a guard dog.  Today the Kerry has spread around the world as a companion and working dog.  Despite a Kerry Blue winning Crufts (the most important UK dog show) in 2000, it remains an "unfashionable" breed, and is distinctly uncommon; however, it not as threatened as some of the other terrier breeds such as Skye Terrier, Sealyham Terrier, and Dandie Dinmont Terrier. The English Black and Tan Terrier is an extinct species of dog that was drawn into The Kennel Club as the Welsh Terrier and that remains extant outside of the Kennel Club as a "Fell Terrier". The English white terrier (also known as the White English terrier or Old English terrier) is an extinct breed of dog.  The English White terrier is the failed show ring name of a pricked-ear version of the white fox-working terriers that have existed in Great Britain since the late 18th Century. The Teddy Roosevelt Terrier is a small to medium-sized American hunting terrier.  Lower-set with shorter legs, more muscular, and heavier bone density than its cousin the American Rat Terrier.  There is much diversity in the history of the Teddy Roosevelt Terrier breed and it shares a common early history with the American Rat Terrier, Fox Paulistinha and Tenterfield Terrier.  It is said the Rat Terrier background stems from the terriers or other dogs that were brought over by early English and other working class immigrants.  Since the breed was a farm, hunting and utility dog there was little to no planned breeding other than breeding dogs with agreeable traits to each other in order to produce the desired work ethic in the dog.  It is assumed that the Feist (dog), Bull Terrier, Smooth Fox Terrier, Manchester Terrier, Whippet, Italian Greyhound, the now extinct English White Terrier, Turnspit dog and or Wry Legged Terrier all share in the Teddy Roosevelt Terrier's ancestry.  These early Ratting Terriers were then most likely bred to the Beagle or Beagle cross bred dogs (for increased scenting ability) and other dogs.  Maximizing the influences from these various breeds provides the modern Teddy Roosevelt Terrier with a keen sense of awareness and prey drive, an acute sense of smell and a very high intellect.  Although they tend to be aloof with strangers they are devoted companion dogs with a strong desire to please and be near their owners side at all times.
Answer: Blue Paul Terrier