CLASSIFICATION
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Squaliformes
Family: Squalidae
Genus: Squalus
Species: Squalus acanthias
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Squaliformes
Family: Squalidae
Genus: Squalus
Species: Squalus acanthias
HISTORY
Sharks have been around for millions of years. Over the years the shark's body and behavior have changed in order to adapt to the environment. There are few differences between prehistoric sharks and modern day sharks. The spiny dogfish is no exception with its spines behind its fins. One of the most notable differences is size. This is due to the size of prey that is available to the sharks. Sharks used to prey on much larger animals. One shark that stands out is megalodon. This shark is believed to have hunted large whales such as blue whales. Nowadays sharks tend to hunt smaller mammals such as seals and sea lions. Still, despite the smaller size, sharks have remained at the top of the food chain.