''Entobia'' is a
trace fossil
A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, ...
in a hard substrate (typically a shell, rock or
hardground
Carbonate hardgrounds are surfaces of synsedimentarily cemented carbonate layers that have been exposed on the seafloor (Wilson and Palmer, 1992). A hardground is essentially, then, a lithified seafloor. Ancient hardgrounds are found in limestone ...
made of
calcium carbonate) formed by
sponges as a branching network of galleries, often with regular enlargements termed chambers. Apertural canals connect the outer surface of the substrate to the chambers and galleries so the sponge can channel water through its tissues for
filter feeding
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...
(Bromley, 1970). The fossil ranges from the
Devonian to the Recent (Taylor and Wilson, 2003; Tapanila, 2006).
References
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External links
Image of ''Entobia cretacea'' as a cast showing canals and chambers in three dimensions
{{Taxonbar, from=Q3055109
Boring fossils