Fastest animals
The fastest land animal is the cheetah, which has a recorded speed of . The peregrine falcon is the fastest bird and the fastest member of the animal kingdom with a diving speed of . The fastest animal in the sea is the black marlin, which has a recorded speed of .
Ophthalmosaurus
Calculations suggest that a typical "Ophthalmosaurus" could stay submerged for approximately 20 minutes or more . The swimming speed of "Ophthalmosaurus" has been estimated at 2.5 m/s or greater, but even assuming a conservative speed of 1 m/s, an "Ophthalmosaurus" would be able to dive to 600 meters and return to the surface within 20 minutes.