Dinosaurs 4th Grade

 Millions of years ago, long before there were any people, there were dinosaurs. Dinosaurs were one of several kinds of prehistoric reptiles that lived during the Mesozoic Era, the "Age of Reptiles." Dinosaurs are some of the most magnificent creatures to walk our planet.

The largest dinosaurs were over 100 feet (30 m) long and up to 50 feet (15 m) tall (like Argentinasaurus, Seismosaurus, Ultrasaurus, Brachiosaurus, and Supersaurus). The smallest dinosaurs, like Compsagnathus, were about the size of a chicken. Most dinosaurs were in-between.

It is very difficult to figure out how the dinosaurs sounded, how they behaved, how they mated, what color they were, or even how to tell whether a fossil was male or female.