Okay, a bestiarii is a gladiator who fights beasts.
This book by an excellent gun writer, James Tarr, is a fairly near future read. The civil war in Mexico has been going on for years. The rebels have multiple old Soviet era weapons and some honcho decides to kidnap someone with a lot of dinero to pay a ransom. So a plan, a good plan, is put in motion. Suitable money is passed out to get people to do what is needed and a helicopter goes down with the person on board. Most survive the hard landing. The rebels go to the crash site, in the mountains expecting to pick up the survivors but run into pretty strong resistance. Here's where a PDW really comes in handy. The survivors start for a base on foot and the base is many miles away. Some years past scientists have managed to resurrect some dinosaurs for entertainment purposes and when the venues go bust the animals are not all killed. And, that's where the 'Bestiarii" comes in.
It's a good read. It's nice to have a minigun when you need it.
