A major fossil discovery could prove that the design of a human jaw actually comes from a fish.
The ancient fish Metaspriggina swam in the rivers of the Canadian rockies around 505 million years ago. From fossils, experts at the University of Cambridge have found that these were some of the first vertebrates to appear on Earth. Fossilised evidence shows that these creatures had arches of bone along its back that went all the way to up to its heading to make an early version of a jaw.
From here on out, other species of fish and eventually land-based lizards and mammals took on jaws. This era is known as the ‘Cambrian explosion’ when a scale of rapid evolution took place including the first jaws in animals.