Ray-finned fish (Actinopterygii) evolved over 400 million years ago and are so-called because their fins have a web of skin between several spines. Today, they are the most diverse group of vertebrates with more than 30,000 species which is around half of all living vertebrates on Earth.
The specimens in this gallery are around 85 million years old. By this time, evolution had produced many sorts of fish, types like these being similar in many ways to modern fish. Many specimens of these species have been found which tell us that they probably swam in large schools.