Fig. 1: Part and counterpart of two fossil spiders shown in plain light and under UV illumination.

Fossils Aix_25 (a) and Aix_17 (b), shown in plain light and under UV illumination. In plain light, the fossils do not contain many discernible details, but under UV illumination, the autofluorescence reveals additional detail, as areas of the spider autofluoresce yellow (a) and red (b).