Ottawa's Plumulites Canadensis, an extremely ancient fossil, was dug by an amateur Nepean Fossil collector. The fossil had surfaced out from rock and soil removed from the construction of an underground garage for the World Exchange Plaza.

The worm is a member of the machaeridian family and is one of only 8 specimens identified. They were annelid worms which belong to the group of leeches, earthworms and bristleworms which are now commonly found everywhere.

Rudkin was the first to recognize its scientific significance.

He said that "the mystery fossil was clearly not another trilobite, and I although couldn't be certain, I thought it might be some sort of annelid worm with broad, flattened scales. James, the collector, generously agreed to lend me the specimen and I realized immediately it was a complete, fully articulated machaeridian!," he said.

In 2008, Rudkin along with Jakob Vinther and a team of paleontologists described new machaeridian fossils from remote mountain localities in Morocco, revealing their relationship to annelid worms.

The descriptions of the Ottawa Specimen are published in the current Paleontology.