People have been trying to remove rocks using sledgehammers and crowbars from a beach where a 220 million-year-old dinosaur footprint was found.
Described as the "best specimen ever found", the footprint was discovered by four-year-old Lily Wilder during a trip to Bendricks Bay, near Barry, last month.
It is impossible to tell which dinosaur made the print, but as it is 10cm long it is believed to be from a type that stood 75cm tall and was 2.5m long.
Permission had to be sought from Natural Resources Wales to legally remove the fossil from the beach, which is a site of Special Scientific Interest.
It was removed last week and will be studied by experts at the National Museum in Cardiff.
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Despite this, around 50 people headed to the beach at the weekend and some were equipped with tools to try to remove rocks from the site.
The beach where the fossil was found is a Site of Special Scientific Interest, making it illegal to remove, damage or destroy rocks, and those who do can be fined up to £20,000.
Natural Resources Wales explained that "several areas" of the site had been damaged as a result of people trying to take items away with them.
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A spokesman said: "We’ve been made aware of a number of reports of anti-social behaviour this weekend, following the news of a new dinosaur footprint being discovered at a beach in south Wales.
"Around 50 people attended the site near Barry – and although the majority of visitors left no trace of their visit, we’ve unfortunately received reports of several people trying to remove rocks with sledgehammers and crowbars, leading to several areas of the site being damaged.
"The site where the fossil was discovered is a Site of Special Scientific Interest (SSSI) which contains geological features that require careful site management in order to protect and preserve them.
"SSSI are protected under the Wildlife and Countryside Act and it is illegal to remove, damage or destroy rocks from this site without permission. This can lead to fines of up to £20,000.
"Under the current Welsh Government guidelines you should only visit the site if you live locally to the area."
Anyone who sees somebody attempting to remove rocks from the area is urged to report it by calling Natural Resources Wales' incident hotline on 0300 065 3000.
