India, July 17 -- Kris Jenner is mourning the loss of her mother, Mary Jo "MJ" Shannon, who passed away at the age of 91. The Kardashian-Jenner matriarch announced Shannon's death on social media, paying tribute to the woman she described as the "heart" of their family.

"Today, we said goodbye to my beautiful Mommy MJ," Jenner wrote. "There are no words that could ever capture what she has meant to me or the heartbreak of having to say goodbye."

She added that her mother taught the family "to love your family fiercely, to be kind, to show up for the people you love, and to never take a single moment together for granted."

A cause of death was not revealed.

As fans remember Mary Jo Shannon's role in the Kardashian family's story, inter...