1) Call Allosaurus a T-Rex, or show them videos of kids and adults mistaking it for everyone's favourite bone-crushing, eagle-eyed coelurosaur.
2) Say Allosaurus has a weak bite force comparable to that of a lion.
3) Remind them that Allosaurus constantly gets shelved so that Tyrannosaurus, Giganotosaurus, and Spinosaurus can enjoy the spotlight for the billionth time.
4) Tell them the reason why Allosaurus means "different lizard" is because while all the other dinosaurs are cool, Allosaurus is different in that it's not.
(This post is a joke. Allosaurus is actually one of my favourite dinosaurs).
