Ophiomorpha

{{Short description|Trace fossil}}

{{Ichnobox

| fossil_range = {{fossil range | Early Permian| Recent | refs=In near-shore environments, at least: {{Cite book|url=https://books.google.com/books?id=CZ1AB51LgtkC&q=ophiomorpha+ordovician&pg=PA174|title=Palaeoecology|isbn=978-0-412-43450-1|last1=Brenchley|first1=Dr P. J.|last2=Brenchley|first2=P.|last3=Harper|first3=D.|date=1998-12-18|publisher=CRC Press }}}}

| taxon = Ophiomorpha

| authority =

| subdivision_ranks = Ichnospecies

| subdivision = {{Species list

|O. nodosa|

|O. rudis|

| others...}}

}}

File:ophiomorpha elk basin.jpg of the Parkman Member of the Clagget Formation in Elk Basin on the Montana/Wyoming border]]

File:Ophiomorpha.jpg sandstones in Bohemian Cretaceous Basin, near Hřensko in Czech Republic]]

Ophiomorpha is an ichnotaxon, usually interpreted as a burrow of an organism (specifically a crustacean{{cite book|url=https://books.google.com/books?id=t6wpKir8Hb0C&q=ophiomorpha+ordovician&pg=PA134|title=The Application of Ichnology to Palaeoenvironmental and Stratigraphic Analysis|first=D.|last=McIlroy|date=1 January 2004|publisher=Geological Society of London|isbn=978-1-86239-154-3}}) living in the near-shore environment. The burrow lining is more or less smooth on the inside, and densely to strongly mammalated or nodose on the outside, due to the packing of nodules for support of the burrow. Branching is irregular but Y-shaped where present. It (particularly O. nodosa) is often considered part of the Skolithos ichnofacies, where it has occurred (i.e. nearshore environments) since the early Permian,{{Cite book|url=https://books.google.com/books?id=CZ1AB51LgtkC&q=ophiomorpha+ordovician&pg=PA174|title=Palaeoecology|isbn=978-0-412-43450-1|last1=Brenchley|first1=Dr P. J.|last2=Brenchley|first2=P.|last3=Harper|first3=D.|date=1998-12-18|publisher=CRC Press }} though it (particularly O. rudis) has also occurred in deep water settings (Nereites ichnofacies) since the Late Jurassic, such as well-oxygenated turbidites.{{cite journal|doi=10.1016/S0031-0182(01)00218-8|title=The oldest deep-sea Ophiomorpha and Scolicia and associated trace fossils from the Upper Jurassic–Lower Cretaceous deep-water turbidite deposits of SW Bulgaria|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=169|issue=1–2|pages=85–99|year=2001|last1=Tchoumatchenco|first1=Platon|last2=Uchman|first2=Alfred|bibcode=2001PPP...169...85T}}

More generally Ophiomorpha and other crustacean-generated burrows first become prominent in the Jurassic.{{cite book|url=https://books.google.com/books?id=kztUtwymPIMC&q=ophiomorpha+ordovician&pg=PA285|title=Ichnology: Organism-Substrate Interactions in Space and Time|first1=Luis A.|last1=Buatois|first2=M. Gabriela|last2=Mángano|date=11 August 2011|publisher=Cambridge University Press|isbn=978-1-139-50064-7}}