Cruziana

thumb|270px|right|Cruziana from the Devonian [[Brallier Formation or Harrell Formation.]]

Cruziana is a trace fossil (fossil records of lifeforms' movement, rather than of the lifeforms themselves) consisting of elongate, bilobed, approximately bilaterally symmetrical burrows, usually preserved along bedding planes, with a sculpture of repeated striations that are mostly oblique to the long dimension. It is found in marine and freshwater sediments. It first appears in upper Fortunian rocks of northern Iran and northern Norway. Cruziana has been extensively studied because it has uses in biostratigraphy (specific scratch patterns are unique to specific time intervals), and because the traces can reveal many aspects of their makers' behavior.