''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
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through ...
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
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
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