Diagnosis. Leptichnus with sub-circular, elliptical or pear-shaped pits uniserially arranged, sometimes with a thin groove extending between the pits but never linking them. The pits have their long axes congruent with the linear direction of the series. Series commonly branch to give new uniserial series.
Dimensions. Pit long axes c. 0·3–0·9 mm, short axes c. 0·1–0·2 mm. In the holotype specimen, pit long axes measure
0·6–0·9 mm, short axes 0·17–0·21 mm.

Leptichnus dromeus is distinguished from L. peristroma by lacking multiserial pit arrangement. It is produced by encrusting cheilostome bryozoans with runner-type colonial morphologies which may branch frequently, usually in the form of trifurcations with pairs of daughter branches diverging at angles of 45–908 from opposite sides of a parental branch.