Start dinosaur lessons by helping the children to understand more about the time and environment dinosaurs lived in. Hang pictures of dinosaurs and of prehistoric times on the board. Explain to the children that dinosaurs lived long before any humans were born. Tell the children that "0" is the amount of dinosaurs that are alive today. Have the children write the number zero and draw a picture of a dinosaur. Explain to the children that people know dinosaurs lived because of evidence like fossils and bones. Look around the classroom to see if you find evidence that children learned about dinosaurs today. Tell the children to take their evidence home to show their parents.
Explain to the children that dinosaurs were very big. The Tyrannosaurus Rex averaged about 40 feet tall, which is about 6-1/2 times bigger than the student's dads, and this is one of the medium-sized dinosaurs. Help the kids measure a T. Rex. Take 40 feet of string, and make a paper chain to be this length. Lay the paper chain in a straight line, and have the children lie down alongside it to see how many students are needed to make a T. Rex. You might have to go outside to do this.
Teach the children more about dinosaur evidence. Place a diaper bag, a girl's diaper, a pacifier and a baby's bottle on your desk before the children come in. Ask them if they can find evidence to guess who was here before they came in. Ask them what they see on your desk. Do baby boys usually wear pink diapers? Purchase a dinosaur bones kit, and hang three dinosaur pictures on the board, ensuring one of the pictures is the same kind of dinosaur as in the bone kit. Give each student a brush and a disposable bowl filled with sand or cornmeal, with one of the dinosaur bones buried in it. Have the students "excavate" the bone using only one hand and the brush. Assemble the dinosaur skeleton as a class, and figure out which dinosaur they uncovered.
Gather pictures of Apatosaurus, Hadrosaurus, Tyrannosaurus Rex and Triceratops dinosaurs and post them on the board. Explain to the students that there are two kinds of dinosaurs, and they are grouped by the shape of their hip bones. Some dinosaurs are bird-hipped and some are reptile-hipped. Hold your hand in the shape of the two kinds of hip bones and help the students do the same. For reptile hips, hold the index finger and thumb out in an "L" shape and hold the L like a triangle shape parallel with the ground. For bird hips, hold the index finger and thumb like a "C" shape and cup the hand under to point the shape toward the elbow. Ask the students if they can decide which dinosaurs on the board are reptile-hipped and which are bird-hipped.