fossil drag mark
Fig 1. The entire drag mark created by the drifting shell of a dead ammonite (Subplanites rueppellianus), with close-up of
A. The first portion of the drag mark clearly showing two prominent ridges. B. Drag mark showing two prominent ridges with additional
faint ridges. C. Drag mark showing four prominent ridges and a gentle curve. D. Drag mark showing numerous prominent ridges, along
with the ammonite. Large scale measures 1 m. Small scales measure 10 cm. See ref. 1 for source.
Fig 2. The ammonite Subplanites rueppellianus, the producer of the drag mark.
The shell is approximately 10cm across. See ref. 1 for source.