Staff at a Thailand crocodile farm are nursing an unusual new arrival: a pair of conjoined crocodiles.

Chang and Eng - named after the world's most famous Siamese twins - were hatched on Saturday at the Samut Prakarn zoo just south of Bangkok.

The animals each have a head, but share a common lower body with one tail and have four legs each.

A spokeswoman at the farm, which claims to be the world's biggest with 60,000 crocodiles, said the crocodiles were being cared for by staff.

Human drama

Among humans, the birth of two connected babies can be extremely traumatic and approximately 40-60% of these births are delivered stillborn. About 35% survive just one day.

The overall survival rate of conjoined twins is somewhere between 5% and 25%.

The original Chang and Eng were born in 1811 to a fishing family in Samut Songkram, a seaside province near Bangkok, joined by an eight-centimetre cord of flesh just below the chest.

Thailand was then called Siam, and the twins' unusual physical characteristic gave birth to the phrase Siamese twins, which means identical siblings joined at birth.

Chang and Eng went to the United States when they were 17 years old, and gained fame and wealth by displaying themselves. They married, had children and lived until the age of 62.