[arnsholt]

Carbon dating can help, since it gives an upper bound on the age (a terminus post quem if you want to be fancy; the manuscript wouldn't have have been written while the parchment was still hide on a cow) and the pages would probably have been written on fairly recently after being turned into parchment. Of course parchment can have its initial contents scraped off and reused, or overwritten which complicates matters. But as you say, an expert palaeographer can probably eyeball the age of a manuscript quite often, since the style of handwriting is largely dictated by both time and place. For example, to my (untrained) eye the hand in the manuscript in the article looks a bit like an insular script[0], which is specific to the British isles at time in question. An Italian of French manuscript of similar age would have a different script. And as others have pointed out for some manuscripts record sleuthing can find stuff surprisingly far back.

0: https://en.wikipedia.org/wiki/Insular_script

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