Gyrochorte 'highways' and their environmental significance in shallow-marine sediments

WETZEL, ANDREAS; CARMONA, NOELIA; PONCE, JUAN

ACTA PALAEONTOLOGICA POLONICA

INST PALEOBIOLOGII PAN

Año: 2020 vol. 65 p. 209 - 218

0567-7920

The reworking of a trace by a subsequently following organism represents a so-called sequorichnial behavior and leadsto formation of a ?burrowing highway?. Burrowing highways occur more frequently than assumed in the fossil record.Their ichnological and sedimentological meaning is elucidated by using the trace fossil Gyrochorte. Gyrochorte producersexploiting sandy event beds tend to use ?burrowing highways? in the same direction. Evidently, the Gyrochorte producersare thigmotactically highly sensitive as they can recognize a burrow produced by the same species because of the lessdensely packed grains, a somewhat increased mud content, and supposedly mucus segregated within the burrow. Thesechanges make the reworking of pre-existing burrows energetically advantageous. However, in shallow-marine settingsmucus is degraded rapidly and loose sediment consolidates in a short while. Therefore, the time to recognize a pre-existingburrow appears to be limited and a rather high number of organisms is a prerequisite for reutilization of a previous trace.?Burrow highways? potentially represent an additional criterion to characterize an opportunistic population strategy