Pieces of bone found at the Metrolinx soil removal at Allandale Station forced officials to abruptly shut down the operation for about two weeks.
Experts have determined the remains were not human.
Small bone fragments were found on Oct. 17, the day the operation began, according to a Metrolinx spokesperson.
Those remains were examined on site and work was allowed to proceed.
"It was confirmed by Metrolinx’s licensed archaeology consultant, Archaeological Services Inc. (ASI), that the bones were a jaw bone and a tooth that were determined to belong to a fox," said Alex Burke, Senior Advisor, Media Relations and Issues for Metrolinx.
Two days later, another bone was found which forced a work stoppage until the bone could be sent away for analysis.
Burke says it was determined the bone was the humerus of a small mammal.
A source said the site was shut down for ten days and work resumed this week.
Representatives from Huron-Wendat (HW) and Williams Treaties First Nations (WTFN) are on-site daily to monitor activity in the event that potentially indigenous remains are found on the land.
They are joined on-site by ASI, the licensed archaeology consultant retained by Metrolinx.
The bones were also examined by a lecturer at Trent University holding a PhD in bio-archaeology.
The West Berm Stockpile is being removed from the Barrie Layover Facility to complete construction of a 7th layover track that will accommodate planned service increases on the Barrie corridor.
"Work at the Barrie Layover Facility West Berm Stockpile is proceeding under the current visual monitoring program that aligns with Ministry of Tourism Culture and Sport (MTCS) protocols," Burke said. "MTCS has indicated during discussions that the ongoing due diligence work presently being conducted goes above and beyond standard requirements."
Metrolinx says the ongoing archaeological due diligence is being conducted to address concerns over the potential presence of archaeological artifacts.
The stockpile of soil was previously cleared by an archaeological assessment and this is additional due diligence, Burke said.