|Plesiosaurs in general are thought
to be among the slowest marine reptiles. Their long necks are assumed to
have created a lot of resistance reducing their hydrodynamic characteristics.
For example, the long neck of Elasmosaurs (another type of Plesiosaur)
would have made them very slow. Their necks were nearly twice as long as
their body. It
is believed that Plesiosaurs did not rely on speed to chase down prey, but
instead probably ambushed prey from below, coiling and striking their long
necks quickly like a snake. In this way they could sneak up on prey by
lurking in the darkness of deeper water, and then strike upwards quickly
to take prey by surprise (Everhart, 1998).