Gnathichnus

Gnathichnus is a trace fossil on a hard substrate (typically a shell, rock or hardground made of calcium carbonate) formed by regular echinoids as they scraped the surface with their five-toothed Aristotle's Lantern feeding structures.^[2]

Gnathichnus
Gnathichnus pentax echinoid trace fossil on an oyster from the Cenomanian of Hamakhtesh Hagadol, southern Israel.
Trace fossil classification
Ichnofamily:	†Gnathichnidae
Ichnogenus:	†Gnathichnus Bromley, 1975
Type ichnospecies
Gnathichnus pentax Bromley, 1975
Synonyms[1]
Roderosignus Michalík, 1977 Asteriastoma Breton, 1992

Oral surface of Strongylocentrotus purpuratus showing the teeth of the Aristotle's Lantern, which can make the trace Gnathichnus.