One of the footprints on the track left by a tetrapod on Valentia Island, Co Kerry, 350 million years ago has been damaged.
Dúchas, the heritage service, does not believe the damage is the work of a professional fossil hunter. However, it is increasingly aware of the vulnerability of Europe's first tetrapod track and the longest of the known trackways in the world.
Planning permission has been received for works surrounding the site. A pathway and stone wall will be developed, making the site safer and more secure. A park for 15 cars provided. A caretaker will be appointed later, according to Mr Pat Foley of Dúchas.
In the meantime, vigilant locals and the landowner, Mr Patrick Curran, keep a careful watch on the site, at the edge of the sea in Dohilla.
Mr Curran was bringing up mussels from the sea at the Point, just down the cliff from Valentia Radio Station, in 1992 when Mr Iwan Stossel, a Swiss geology student came running over to say he had found rare footprints on the slate next to the sea on Mr Curran's land.
Ireland is only now waking up to just how rare those prints are.
There are more than 150 prints in a distinct track, which has been verified as the first discovery of its kind in Europe of a tetrapod and the longest known such track in the world. It is thought the ancient creature, the ancestor of both mammals and dinosaurs, left its mark on Dohilla about 350 million years ago.
The prints on the Valentia slate were probably made - when Ireland was still south of the Equator - when the tetrapod walked in a shallow tropical stream during the Devonian period, the age of fish and fin when limbs began to emerge.
The name tetrapod is from the Greek for four-footed. Scientists have come up with an image of a squat, crocodile-like animal with heavy legs and a tail.
Hundreds of visitors walk down to the unmarked site during the summer, according to locals, many having taken the ferry across from Renard near Caherciveen.
The visitors are mostly German, American or Swiss, but an increasing number are Irish. They have all come to see the dinosaur prints.
The tracks are clearly visible from the clifftop.
When the sun shines a certain way the dog-like prints almost light up.
Dúchas plans to erect a structure to make it safe to look down from the top of the cliff, and steps will be built to enable visitors to go down for a closer look.
The work, expected to cost around €70,000, will begin in the next few weeks, Mr Foley of Dúchas said.
Islanders are beginning to realise what the prints will mean to Valentia. Mr Richard Foran, the lifeboat secretary and lighthouse keeper at Skellig, says it will have a dramatic impact on the island.
"The tetrapod will be the making of the island. In a few years this will be as important and more accessible than the Skellig," he said.