Several small, dome-like roughly ovate calcitic structures with lobed margins found in Miocene aeolianites of the Namib Desert resemble the clover-leaf shaped roof webs made by extant 'trapdoor' spiders of the burrowing genus Seothyra(Araneae, Eresidae). These webs consist of a mat of densely-woven silk with slits around the periphery, which is covered, on its upper surface, by sand. The fossils indicate that the genus Seothyra or a similar form of spider, has inhabited the Namib since the Miocene period, and that the capture ecology of the Seothyra type is an ancient one. Keywords: Miocene, Spider's webs, Namib Desert, Aeolianites, Namibia.