Fig. 5: Museum-quality sand spikes from the former Liebherr outcrop in Ochsenhausen.

a Typical sand spike aggregate with roundish to cauliflower-like heads and uniformly orientated tails. b, c Sand spike aggregates with roundish (b) and cauliflower-textured (c) heads and uniformly orientated tails. The tail of the left individual in b is slightly deformed by the sand spike to the right. d Sand spike individuals seemingly formed during a protracted, dynamic process. The sand spike to the left speared and deformed the sand spike to the right. e, f A typical nail-like sand spike showing the surface (e) of the cut specimen and the interior side of the same sand spike cut in half. It is noteworthy that the sand spike head is more densely cemented than the spike tail that contains some visible open pore space. g, h Two heads of sand spikes cut in two. The interior of the sand spikes does not show any structural features or concretionary cores. All photographs taken by V.J.S. Sand spikes in a and d are shown with approval by the Braith-Mali-Museum in Biberach a. d. Riss where these specimens are on display.