Extended Data Fig. 2: Taphonomy of the Haiyan Lagerstätte.

a–g, Soft-bodied tissue preservation of a new hemichordate, YKLP14443. a, Microprobe EDS spectrum of the matrix. b, Stereo microscope image. c, Backscatter electron (BSE) image showing pyrite on the surface of fossil, black arrow indicates the boundary of the fossil and the matrix. d, Elemental map overlay, including silicon (Si), aluminium (Al), oxygen (O), potassium (K), iron (Fe). e–j, individual elemental maps e, Iron. f, Silicon. g, Aluminium. h, Carbon (C). i, Sulfur (S). j, Oxygen. k, Unpolished mudstone from the lower level of the Haiyan Lagerstätte. l, Polished mudstone from the lower level of the Haiyan Lagerstätte. Scale bars, 200 μm (c–i), 1 mm (b),10 mm (k, l).