How Fish Evolved...
Did you know that life in the sea began about 3.1 - 3.4 billion years ago? Early fish that are known only from fossil records are called Prehistoric fish.Those fish are the earliest known vertebrates. Prehistoric fish include the first fish, that is now extinct but lived through the Cambrian to the Tertiary period.The Haikouichthys is a type of fish that lived 518 million years ago! Scientists say that this may be one of the first fish alive! Fish that lived 500 million years ago did not have jaws. These jaw-less fish lived for about 100 million years until the first jawed fish evolved!