“the first fossilized example of this extremely decay-prone tissue. “
“fossilized” Seems pretty clear from your own example.
You need to be careful about what they are calling fossils these days. For instance, take a look at the following description of a T rex. “fossil”:
“ In modern bone, removing the minerals leaves supple, soft organic materials that are much easier to work with in a lab. In contrast, fossilized bone is believed to be completely mineralized, meaning no organics are present. Attempting to dissolve the minerals from a piece of fossilized bone, so the theory goes, would merely dissolve the entire fossil. But the team was surprised by what actually happened when they removed the minerals from the T. rex femur fragment. The removal process left behind stretchy bone matrix material that, when examined microscopically, seemed to show blood vessels, osteocytes, or bone building cells, and other recognizable organic features.”