Michael Alan Taylor

Academic paper

Nature (News and Views)

319

179

THE plesiosaurs, large extinct carnivorous marine reptiles of the Mesozoic period, have always excited dispute over how they swam and reproduced. Did they swim like marine turtles, 'flying' with winglike, hydrofoil limbs. or did they row by moving their limbs back arid forth (Fig. la, b)? And did they come on shore to lay eggs, or give birth in the water to live young? Recent research provides a new animal model that might answer these questions.
In 1975, Jane Ann Robinson argued that the plesiosaurs must have flown underwater, like turtles and penguins, be-cause this movement was the most effic-ient use of their long hydrofoil-like limbs2. If the plesiosaurs had rowed, they should have had webbed folding feet like those of ducks. She suggested that they swam by flapping both pairs of limbs up and down, producing lift force that propelled the animal forwards.

English