How long ago did megafauna live?

Did ankylosaurus live alone or in groups? What is bigger a t-rex or a African elephant? What is a crocadilion? What are the Physical Characteristics of a T Rex dinosaur? Why can't people live on the prarie? When was the first dinosaur mask made? What evidence suggests to researchers that birds and dinosaurs evolved from a common ancestor? What does the T in Base-10 T stand for? Why was belle boyds work important in the period of time that she lived in? What did the verociraptor dinosaur eat? The sauropods lived until what era? Who or what is a paleaontologist? Who are the parents for the island dragon for dragon story? Which dinosaur lives in water and has flippers? Why is it important to understand the cause of the dinosaurs extinction? What do you get what n you breed a tree and fire dragon in DragonVale? How many years ago did the dino's die? What is a weight of a T rex? How do you combine a monster in my monster rancher? What family did the velociraptor live in?