While soft tissue rarely preserved, that doesn’t mean we don’t find examples of it. For example, below are sections of Triceratops skin, featuring large scales, some of which qualify as “feature scales”
Clayton Phipps and co have discovered what is likely a nearly complete Ankylosaurus in Hell Creek sediments. This is ironically probably the rarest thing he has ever worked on - Ankylosaurus is known from like 1 good specimen and 3 or 4 total. Look at how pristine that skull is!