This 2013 video says about itself:
Translated from Nu.nl in the Netherlands:
Boy finds in Gelderland bones of prehistoric cave lion
August 16, 2015 20:20
The now ten-year-old Enzo Smink in the Gelderland town Wekerom has found an absolutely unique find. On a secluded beach nearby he found the lower jaw of a rare prehistoric cave lion.
Smink made the discovery as early as the summer of 2012, but no one then realized what the boy had found. The remains landed in a box with his grandmother.
Only when the boy earlier this year got the bones out again for a speech, his mother decided to send a picture of it to specialists.
“An archaeological finding of this format is probably done once in twenty years,” says director René Fraaije of the museum to NU.nl. “Cave lions at that time were already rare, let alone that ten thousand years later their bones are often found.”
The cave lion was the largest predator of the time of the mammoths. This animal lived in most of Europe then. The name does not refer to the lifestyle of the enormous feline, but to the place where most of the remains of the lions have been found.
The animal became extinct at the end of the last ice age, roughly ten thousand years ago. This was due to the changing climate and the extinction of the prey animals that the lions fed on. Most information about the appearance of the cave lion is derived from prehistoric cave drawings.
Enzo Smink will transfer the find officially to the prehistoric museum on Monday. There the lower jaw will get a special place in the collection.