The Neapolitan Mastiff or is an Italian breed of large guard dog. The English Mastiff is a breed of large dog. The Tibetan Mastiff is considered a primitive breed. In name and form the Cane Corso predates its cousin the Neapolitan Mastiff. The Pyrenean Mastiff is a very large dog. Bull Mastiff, is River's unnamed Bull Mastiff. The original Tibetan Mastiff breed from its native range usually weighed . Many guard dog breeds have a greater amount of molossoid or mastiff DNA. British Molossian dogs were developed into the English Mastiff. European and Asian records dating back 3000 years show dogs of mastiff type. It is well muscled and less bulky than most other Mastiff breeds. It should not be confused with the Pyrenean Mastiff. The Fila Brasileiro is described as a Brazilian Mastiff or a Brazilian Molosser. It looks like a medium version of Tibetan Mastiff. This was long assumed to have been a Tibetan Mastiff.