''Gordia'' is an
ichnofossil
A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of part ...
known from Precambrian
to modern sediments and is the most common trace fossil in the
Kaili biota displaying "smooth, cylindrical or subcylindrical, non-branching, winding and irregularly curving burrows, commonly self-overcrossing".
Probably made by a worm-like creature displaying fodinichnial (sediment scavenging) behaviour.
[ It takes the form of unlined, curving parallel-walled burrows that often end with a nub, probably created as the creature probed the over- or under-lying sediment.]
References
Burrow fossils
Invertebrate paleozoology
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