Gnathichnus

{{Short description|Trace fossil}}

{{Ichnobox

| image = Gnathichnus Cenomanian 020413.JPG

| image_caption = Gnathichnus pentax echinoid trace fossil on an oyster from the Cenomanian of Hamakhtesh Hagadol, southern Israel.

| taxon = Gnathichnus

| authority = Bromley, 1975

| type_ichnospecies = Gnathichnus pentax

| type_ichnospecies_authority = Bromley, 1975

| synonyms_ref = {{cite journal|last1=Wisshak|first1=M.|last2=Knaust|first2=D.|last3=Bertling|first3=M.|year=2019|title=Bioerosion ichnotaxa: review and annotated list|journal=Facies|volume=65|issue=2|page=24|doi=10.1007/s10347-019-0561-8}}

| synonyms =

• Roderosignus {{small|Michalík, 1977}}
• Asteriastoma {{small|Breton, 1992}}

}}

File:Strongylocentrotus purpuratus 020313.JPG showing the teeth of the Aristotle's Lantern, which can make the trace 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.{{cite journal | author = Bromley, R.G. | year = 1975 | title = Comparative analysis of fossil and recent echinoid bioerosion | journal = Palaeontology | volume = 18 | pages = 725–739}}