Complex sentence: Joe Banks, part-time epigrapher found a stone with markings in Mount Hanley that her believes are Ogam script and dates from the 5th century AD, evidence of an ancient Irish settlement in Mount Hanley.
Split into simpler sentences: Joe Banks, part-time epigrapher found a mysterious stone that is believe to hold Ogam script. Know as the Mount Hanley "Ogam" stone, which he believes dates from the 5th century AD and is evidence of an ancient Irish settlement in Mount Hanley.