The Troodon (meaning 'wounding tooth' in Ancient Greek) was a relatively small carnivorous dinosaur which was roughly the size of a large Dog
. They get their name due to the fact that they had serrated edges on their teeth.
Their barbed teeth were indeed a strange discovery, since serrated teeth are usually attributed to herbivorous creatures.
They were quite intelligent and could run at quite a fast pace, meaning that in combat they were very dangerous and should be engaged with good accuracy.