Grave of Gnaeus Musius, Leg XIV?

[caiusbeerquitius]

I wrote above:

Historically the Dacian wars seem to have been an exception: Here the rectangular shields also occur in large numbers on the tropaeum traiani in Adamklissi. Earlier and later a group might very well have either a mix of shields, or either type exclusively.

We also should keep in mind that this may have been a feature only visible among the Legions taking part in the Dacian wars, it may very well be that other contemporary Legionary troops were using the oval shields.