The tuatara of New Zealand, often called a 'living dinosaur', has DNA evolving faster than any other animal yet examined, according to a new study.

The study, by researchers at the Allan Wilson Centre for Molecular Ecology and Evolution, recovered DNA sequences from the bones of 8,000-year-old tuatara and compared them to living tuatara.

'What we found is that the tuatara has the highest molecular evolutionary rate that anyone has measured,' said David Lambert, who led the study.

Scientists expected the tuatara, which does everything slowly - they grow slowly, reproduce slowly and have a very slow metabolism - would have evolved slowly, ScienceDaily reported.

But they evolve extremely quickly, supporting a hypothesis that suggested that the rate of molecular evolution was not connected to the rate of morphological evolution.

Lambert said the finding will be helpful in terms of future study and conservation of the tuatara, and the team now hopes to extend the work to look at the evolution of other animal species.

'We want to go on and measure the rate of molecular evolution for humans, as well as doing more work with Antarctic fish to see if rates of DNA change are uncoupled in these species.

'There are human mummies in the Andes and some very good samples in Siberia where we have some collaborators, so we are hopeful we will be able to measure the rate of human evolution and in these animals too.'

The tuatara, Sphendon punctatus, is found only in New Zealand and is the only surviving member of a distinct reptilian order called Sphehodontia that lived alongside early dinosaurs and separated from other reptiles 200 million years ago.