''Diplocraterion'' is an

ichnogenus An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxa'' comes from the Greek ίχνος, ''ichnos'' meaning ''track'' and ταξις, ''taxis'' meaning ...

describing vertical U-shaped burrows having a

spreite Spreite, meaning leaf-blade in German (or spreiten, the plural form in German) is a stacked, curved, layered structure that is characteristic of certain trace fossils. They are formed by invertebrate organisms tunneling back and forth through se ...

(weblike construction) between the two limbs of the U. The spreite of an individual ''Diplocraterion'' trace can be either protrusive (between the paired tubes) or retrusive (below the paired tubes). Some ichnospecies have both types (e.g., ''Diplocraterion yoyo''). The presence/absence of funnel-shaped openings should not be used as an ichnotaxobase due to the high probability that the upper portions of the trace may have been eroded away. Observation of the orientation of ''Diplocraterion'' in the field is frequently used to determine the way up of

rock strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...

at outcrop. There are several ichnospecies of ''Diplocraterion''.

Ethology Ethology is the scientific study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait. Behaviourism as a term also describes the scientific and objecti ...

The various ichnospecies of ''Diplocraterion'' provide a good example of how

ethology Ethology is the scientific study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait. Behaviourism as a term also describes the scientific and objecti ...

(animal-substrate interactions and behavior) can be interpreted from trace fossils. ''Diplocraterion'' is a classic example of equilibrichnia (equilibrium traces). These types of traces represent gradual adjustments to background sedimentation and erosion rates and reflect the efforts of the organisms to maintain a specific depth within the substrate. This movement within the substrate produces the two types of spreite (protrusive and retrusive) characteristic of ''Diplocraterion'' and other ichnotaxa (e,g., ''

Rhizocorallium ''Rhizocorallium'' is an ichnogenus of burrow, the inclination of which is typically within 10° of the bedding planes of the sediment. These burrows can be very large, over a meter long in sediments that show good preservation, e.g. Jurassic ro ...

''). Most ''Diplocraterion'' show only protrusive spreit (e.g., ''D. parallelum, D. polyupsilon, D. biclavatum''). These indicate that the trace was produced under predominantly erosive conditions where the organism was constantly burrowing deeper into the substrate as sediment was eroded from the top. ''D. yoyo'' has both protrusive and retrusive spreiten indicating highly variable conditions (erosional and depositional) leading to the need for the organisms to constantly adjust itself up and down within the substrate to maintain equilibrium and not become exposed or buried.

Ethology Ethology is the scientific study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait. Behaviourism as a term also describes the scientific and objecti ...

See also

References

Further reading