Page 164 - The Dinosaur Book and Other Wonders of the Prehistoric World (DK-Smithsonian)

Flippers and tails

Plesiosaurus

The long necks of plesiosaurs
had limited flexibility, helping
them stay streamlined.
Flipper bones

Sideways flicks of the
long tail gave Tylosaurus
a burst of speed.
Tylosaurus

Dozens of finger
bones formed the flat,
Ichthyosaurus
paddle-shaped limbs.

The front flippers
were used to steer.
Rhomaleosaurus
Spine bones extended
along the bottom of an
ichthyosaur’s powerful tail.

Geosaurus
The tail was used
like a rudder to help
steer in water.

Powerful limbs
provided propulsion.
This close relative of
crocodiles had a fishlike tail
and small, paddlelike limbs.

Many kinds of prehistoric reptiles gave up feet for swimming, but it could also haul itself
life on land to live in the ocean. Just as onto land to breed, as seals do. Other marine
marine mammals like seals and whales would do reptiles were fully aquatic and probably
later, they adapted to life in water by becoming more agile in the water. Plesiosaurus and its
streamlined and slippery and using their limbs as shorter-necked relative Rhomaleosaurus
162 flippers. Nothosaurus had paddlelike, webbed propelled themselves through water by rowing

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