|Stage 5. Multiple filaments arising from the edge of a membranous structure|
And did a search on "membrane" in the article. It came up in a reference to another study entitled:
"A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well-preserved wing membranes and “hairs” from Inner Mongolia, northeast China" http://www.ivpp.cas.cn/qt/papers/201...6827022386.pdf
That is very interesting.
Multiple filaments stemming from the edge of a pterosaur membranous structure
is of course what I have been talking about.