Ulnaria fanjingensis sp. nov., internal view, SEM A a complete valve B middle part detail from A, note the clear central area C detail of another valve center showing the clear central area D a pole from A, note the tapering valve and rostrate apex E, F two apical details from A, note bilabiate rimoportulae and rostrate apices. Scale bars: 20 μm (A); 5 μm (B–D); 1 μm (E, F).