The biggest marine reptile on record is a 21m-long ichthyosaur, Shonisaurus sikanniensis, from Triassic Period rocks in British Columbia, Canada.

BBC: Arctic sea monster's giant bite

Researchers say the marine reptile, which measured an impressive 15m (50ft) long, had a bite force of about 16 tonnes (35, 000lbs).

BBC: Arctic sea monster's giant bite

Researchers speculate that 2 to 8 new cetacean species and almost 10 marine reptile species (like sea snakes) remain to be discovered.

UNESCO: THEMES

Weighing more than 700 kilograms and reaching more than 1.7 meters in length, the leatherback turtle is the world's largest marine reptile.

CNN: Turtles in race to beat extinction