Fish
20 metres
During the Devonian period, jawed fish diversified rapidly, with all the modern groups emerging and thriving. With over 30,000 known living species, fish account for more than half of all vertebrate species.
Carcharodon megalodon (maximum) Carcharodon megalodon (minimum) Rhincodon typus whale shark Carcharodon carcharias great white shark
PLACODERMS
SPINY SHARKS
Carcharodon megalodon
An extinct class of armoured prehistoric fish, the largest species measuring up to 10 metres in length and weighing up to 3,600 kilograms. They were hypercarnivorous apex predators and dominated the Devonian period, but, being slower and less agile than evolving sharks and ray-finned fish, they succumbed to competition and a series of environmental shocks.
Also known as acanthodians, this class of extinct fish has a misleading name – they weren’t sharks, but they did share features present in both bony fish and cartilaginous fish. In form they somewhat resembled sharks, but their skin was covered with tiny rhomboid platelets.
An extinct species of shark that lived from about 23 to 2.6 million years ago: perhaps the largest and most powerful predator in vertebrate history, reaching a length of 20 metres, with teeth up to 18 centimetres long.
THE AGE OF THE FISHES
Jawless fishes
Placoderms Spiny sharks Cartilaginous fish THE JAW The evolution of the jaw in vertebrates, probably with the Placoderms, was a major step-point in vertebrate evolution. From this point forward diversification was rapid and vertebrates have dominated the predatory niches of the planet ever since.
Ray-finned fish Lobe-finned fish
Amphibians/reptiles/birds/mammals
ORDOVICIAN
CAMBRIAN
550
500
SILURIAN
450
DEVONIAN
400
PERMIAN
CARBONIFEROUS
350
300
TRIASSIC
250
JURASSIC
200
CRETACEOUS
150
100
PALEOGENE
50
NEOGENE
0
04/07/2016 00:00