Sparta was found in Yakutia region in 2018 by the same mammoth bone hunter who discovered a bigger cave lion cub called Boris a year earlier.
They were just ten metres apart.
The first theory was that the cubs must have been from the same family - but now scientists know that the cubs are separated by 26,000 years.
Boris lived some 44,000 years ago and was aged between two to three weeks when he died.