Dinosaurs leave their mark near Nelson 

Source: ONE NewsDinosaur footprints in northwest Nelson, discovered by geologist Greg Browne

• WATCH the video (1:29)

The first dinosaur footprints ever found in New Zealand have been discovered northwest of Nelson.

It is also the first evidence dinosaurs inhabited the South Island.

The 70-million-year-old footprints belong to sauropods - long-necked, long-tailed herbivores.

Greg Browne, the man who discovered the footprints, says the preservation of the footprints was quite special

"The tide basically came in and preserved quite delicate structures," he says.

There are more than 20 footprints and they are still being studied.

Palaeontologist Hamish Campbell says in one of the prints, you can see the heel and toe and how the foot landed and lifted off.

Campbell believes the dinosaur which made the prints was "something about eight metres...and weighing about two to three tonnes".

Scientists are determining how best to protect the footprints, but wind and water means they will erode over time.

"These things are degrading...on the other hand for all that some will disappear completely perhaps there will be new ones," says Campbell.

Browne, a GNS scientist, says it is "absolutely amazing" they are there in the first place because an inter-tidal environment destroys structures very quickly by wind, tides, currents or waves.

He discovered the footprints in six locations over a 10-kilometre area while studying rock and sediment formations. The largest is about 60cm in diameter while most are 10-20cm in diameter.

Browne says they were left in beach sands which were probably quickly covered and preserved by mud from subsequent tides. He has ruled out other explanations for the features in the rock.

Dinosaur bones have been discovered in northern Hawke's Bay, Port Waikato and the Chatham Islands.

Browne says the footprints add useful information about how dinosaurs moved, how fast they moved and how big they were, as well as how soft the sediment was when they moved through the area.