Danielle Hall
Reviewed by Hans Sues (Smithsonian Institution)
At Smithsonian Ocean, we have lesson plans, activities, and resources to help you engage your students in the wonders of our oceans.
Shark Lesson PlanAll Lesson Plans
Anatomy, Diversity & Evolution
Anatomy
A Big Shark
The megalodon is the largest shark to have ever lived in the world’s ocean. Like other sharks, they had streamlined yet powerful bodies built to efficiently cut through the water. Their tailfin undulated side to side and they breathed through gill slits on either side of their head.
Like other elasmobranchs (a group of fishes that includes sharks, rays, and skates), megalodons have skeletons mostly made of cartilage—the hard but flexible material that is found in human noses and ears. This is a defining feature of elasmobranchs, as most fish have skeletons made of bone. Much lighter than bone, cartilage allows sharks to stay afloat and swim long distances while using less energy. It is also very difficult for cartilage to fossilize, so much of what w
•
Carcharodon megalodon
Giant "Mega-Tooth" Shark
Family: Lamnidae
Time
Miocene Epoch
Among the most ancient vertebrates on Earth, sharks first appeared in ancient oceans during the Silurian Period, more than 400 million years ago. This means they were living almost 200 million years before the dinosaurs existed!
Place
The teeth of the giant "megatooth" shark have been found in North and South America, Europe, Australia, India, Japan, and Africa. Scientists believe the shark flourished in warm waters throughout the world.
In Our Region
San Diego Natural History Museum paleontology staff collected teeth from this giant species of shark from Miocene sandstones in Oceanside, California and near Ensenada, Baja California.
Description
This extinct shark was a monster. Scientists think it may have grown as long as 50 feet (15.25 meters). It could have weighed as much as 50 tons (50,000 kg).
Carcharodon megalodon represents the largest, meat-eating fish to have ever lived. The information we have about its size is drawn from comparisons with l