It's amazing the questions a single tooth can ask......
This is a specimen of Homotherium latidens (the scimitar cat) from Robin Hood's cave in Derbyshire....and it was found in deposits that would a) mean it was co-existing in the area with humans, and b) alive as a species pretty recently (like in the last 15,000 years or so). That conjures up some interesting thoughts eh? A now extinct big cat with monster teeth roaming the north of britain (potentially eating the odd bloke) in the last 15,000 years. What a thought! Well bear in mind that the same cave has produced lion, wolf, bear, arctic fox and spotted hyena. Britain is not what it once was.
Truthfully the Homotherium specimen is regarded as more than a bit dodgy. It has a drill hole at the top which suggests it was worn as an ornament by prehistoric peoples and transported into the cave that way (at best) or deliberately planted (at worst). Either possibility just inspires more questions in me. What a fascinating piece.
Darren (as always on topics of zoological interest) has some excellent posts on the topic here and here.