One never knows which, if any, action they take will leave its mark on our world for millennia to come.

For instance, a simple ocean-floor-dwelling worm engaging in its morning constitution 500 million years ago could have never imagined that action would provide a glimpse back in time to humankind today. But such is the case.

SA国际影视传媒淭his (scene) gives us a deeper insight into what was going on at the time,SA国际影视传媒� says Julien Kimmig, who co-authored an article with Brian Pratt for scientific journal Palaios on April 3 describing the scene found at the Rockslide Formation in the Mackenzie Mountains.

The fossilized remains of hyoliths SA国际影视传媒� similar to trilobytes SA国际影视传媒� feeding on the poop left behind by a worm that is similar, and likely related, to todaySA国际影视传媒檚 Bobbitt Worms. That they, and the poop SA国际影视传媒� referred to as coprolite SA国际影视传媒� itself were preserved, given how quickly feces can deteriorate, adds to the luck of the find.

The hyolith would have all died at once. At this time, the oceans were nowhere near as oxygenated as they are today, and the layer of unoxygenated water may have shifted and killed these hyolith, says Kimmig.

Alternately, there could have been a release of methane or brine nearby. Whatever happened seemed to have happened more than once, given the amount of finds researchers have made in the area.

What is today the Mackenzie Mountain range formed part of the floor of a sea basin then, in the Cambrian period, and the continent was closer to the equator and somewhat tropical.

SA国际影视传媒淲e were actually located much closer to the equator at the time than we are nowadays,SA国际影视传媒� says Kimmig. SA国际影视传媒淪o it was warmer, subtropical likely in temperature at the time.SA国际影视传媒�

The scene they found would have played out on a slope in the basin, likely 50 to 100 metres beneath the waterSA国际影视传媒檚 surface.

Researchers have found evidence of other small arthropods nearby but none of the big, nasty ones yet SA国际影视传媒� like the anomalocaris, a nightmarish metre-long shrimp with tarantula-esque mandibles that would have lived at the same time as the hyoliths.

Pratt discovered the Mackenzie Mountain specimens in 1983, and has returned to the area several times to continue the careful excavation of the ancient fossils.

SA国际影视传媒淭hey were weathering out of the outcrop and Brian (Pratt) was just going through the scree slope at the time and found some specimens, in his first field season.SA国际影视传媒�

Kimmig says there is the potential for more significant finds in the Mackenzie Mountains that could help paint humans a fuller picture of EarthSA国际影视传媒檚 heritage.

While the mountains havenSA国际影视传媒檛 been well-explored for these finds, he says there are many Cambrian deposits that have the potential to host outcrops with scenes like this one.

SA国际影视传媒淚f people keep their eyes open when they go through (the area) and look at the rocks, maybe we will find fauna thatSA国际影视传媒檚 as extraordinary as what we found in the Burgess Shale,SA国际影视传媒� he says.

The Burgess Shale, in the mountains of British Columbia, is host to a treasure trove of fossils from this period that has advanced knowledge of the period significantly. Researchers first found fossils there 100 years ago and continue to find them today.