I'm curious as to how they arrived at 330 million years ago.
Fossil was found in rock strata 330 million years old.
In non-scientific articles about science you're not going to get a 10 page long description of how every date in the article was arrived at citing every source and technique used, just as in every newspaper article about some criminal convicted with DNA you're not going to get a 10 page long blow-by-blow description of how the DNA test was done.
"I'm curious as to how they arrived at 330 million years ago."
A guide at a museum was showing tourists a fossil she claimed was 500,011 years old. Someone asked how they could date it so accurately? The guide replied that 11 years ago they were told it was 500,000 years old. :-}
Some scientists swore it couldn't have been a day over 315 million.
The geology of the British Isles is one of the best studied in the world. They have a very clear understanding of the ages of the various geologic layers that those islands are comprised of. It would be simple to identify which layer this feature was located in, and obtain a corresponding age.
God created it 330 million years ago. My scripture book tells me so, "The book of the scorpion."
The best if used by date was stamped on the bottom.