Molosser is a category of solidly built, large dog breeds that all descend from the same common ancestor. The name derives from Molossia, an area of ancient Epirus, where the large shepherd dog was known as a Molossus. See also: Hunting Dog Breeds, Photos
Molossers typically have heavy bones, pendant ears, a relatively short and well-muscled neck, and a short muzzle.
A Mastiff is a large molosser dog known for size and strength. The terms "the Mastiff group" and "the Mastiff" has been used synonymous with the term "molosser". As such, any molosser, including bulldogs, Great Danes, mountain dogs, pit bulls, and even small dogs such as the Boston terriers may be considered "Mastiff" in this broad sense.
However, the term is most commonly reserved for Dog breeds with the word "Mastiff" in their name including many of the largest of all dogs.
See also: The most beautiful dog breeds
French Mastiff or Dogue de Bordeaux
Neapolitan Mastiff or Mastino Napoletano
Japanese Mastiff or Tosa-inu, Tosa-ken
Brazilian Mastiff or Fila Brasileiro
African Mastiff or Boerboel
Majorcan Mastiff or Ca de Bou, Perro Dogo Mallorquina
The Bulldog breeds split from the Molossers in Europe and spread to the New World with colonization. Though smaller, Bulldogs are still considered to be Molosser breeds.
The Bulldog is a medium-sized breed of dog commonly referred to as the English Bulldog or British Bulldog. Other Bulldog breeds include the American Bulldog, Old English Bulldog (now extinct), Leavitt Bulldog, Olde English Bulldogge, and the French Bulldog.
Bulldogs are the 5th most popular purebreed in the United States in 2013 according to the American Kennel Club.
Alano español or Spanish Bulldog
Olde English Bulldogge
Brazilian Bulldog or Bulldog Campeiro
Other molosser breeds:
St. Bernard dog