Plate 153

Crossing trails

These trails were molded by silt, whose fine grain size allows preservation of the slightest detail (the scale on the right is graduated in centimeters). In comparison with the previous example, this trace is characterized by crossings and overlaps. The morphological differences depend on the exploratory strategy of the animal. Most reptation traces, in fact, are made in search of food (feeding traces ). Next plates document more cases in the same respect. This one shows the base of a siltstone bed deriving from varicolored deep-water shales with intercalations of thin-bedded turbidites of Oligocene age.

Northern Apennines (Marecchia Valley, Ligurian complex).

Photo: P. Ferrieri 1992.