There are also signs it may have originally been intended for one of the infants, based on the way the remains were laid out.
According to the researchers the remains “did not occupy the same amount of space in the grave pit”.
One of the bodies was positioned centrally in the pit, while the other was placed up against the wall.
One of the remains also had 53 beads made of mammoth ivory on its pelvis, with signs they were once threaded with string.
The archaeologists wrote: “All 53 beads are remarkably similar in size and shape and the perforations show no sign of use-wear indicating a production for the sole purpose of serving as grave-good.