Fig. 4

Undichna britannica, PIMUZ A/I 5060, equivalent of the Hangenberg sandstone, latest Devonian, El Khraouia, near Merzouga and Taouz. A Photo taken under shallowly angled white light with the main light source from the top right. B Drawing made from the photo in A with the main ichnofossils marked in colours (Diplichnites—light blue, Rusophycus light green). Those belonging to U. britannica are marked in dark orange (main trace), red, and light orange (two somewhat discontinuous secondary traces) while more doubtful parts running subparallel are marked in yellow. The dark orange part was likely produced by the caudal fin