Folker will not be eligible to apply for parole until 2028, said Justice Wayne Dymond, who said his decision in sentencing was influenced by a lack of remorse showed for his girlfriend's remains.
Folker dumped Shirran's body in a remote area on Newfoundland's Southern Shore shortly after he killed her in the couple's apartment in the Kilbride neighbourhood of St. John's.
Dymond said because Folker lied to authorities, Shirran's remains were widely scattered by scavenging animals.
A jury found Folker, 43, who had initially expressed his innocence in Shirran's death, guilty in early November.
The second-degree murder conviction carries an automatic life sentence.
The Crown argued that Folker should not have been eligible to apply for parole for at least 18 years. The defence, though, wanted parole eligibility to fall between 12 and 14 years.
The court was told that Shirran suffered enormous trauma to both sides of her head. The Crown argued that Folker kicked Shirran violently in the head.
Shirran had decided to leave partner
Evidence presented at the trial showed that Shirran had decided to leave Folker, and to care for the couple's young son on her own.
After he killed Shirran, Folker put her body in a car and strapped their son in a car seat. He drove far south to a camping area outside Cappahayden, where he dumped her remains in a remote area.
Parts of her skeleton were discovered weeks later. Court was told that scavenging animals had taken away some of her remains.
In searing victim impact statements read in court two weeks ago, Shirran's family members said they will never recover from her murder.
"The images of Ann Marie's remains are etched in my brain, and will go with me to the grave," wrote Jon Baggs, Shirran's father.
"Losing a child is this mother's worst nightmare. The wound in my heart lies open, gaping, seeping," wrote Diane Baggs, her mother. "I will never see her, hear her voice, or touch her again."
"My anger is black and directed at David Folker," said Dana Harrell, Shirran's brother, who told the court that her death has caused enormous upheaval in his own life, including the loss of his marriage and several jobs.