Barbourofelidae is the name given to a group of ancient animals that existed a very long time ago. They were kind of like really big cats that lived during the Miocene period, which was around 23 to 5 million years ago.
These creatures were much larger than modern-day cats, and they had long, sharp teeth that they used to hunt their prey. Just like how you use your teeth to bite and chew food, they used their teeth to kill other animals and eat them.
Barbourofelidae were also different from modern cats in other ways. They had longer legs and were built differently, which would have made them better at running and hunting large prey. However, they eventually went extinct and are not around anymore. Scientists still study their fossils to learn more about these ancient animals and their place in the history of the world.