Plesiosaurs (meaning “near lizard”) were flippered marine reptiles that existed from the end of the Triassic period 220 million years ago until the end of the Cretaceous 65 million years ago. They were not dinosaurs. Plesiosaurs are divided into two groups: the 
Plesiosauroids with long, snake-like necks, tiny heads, and the Pliosaurs, which had short necks and large heads with powerful jaws.
plesiosaur and pliosaur

A few of Pliosaur’s incredible stats:

• The greatest predator that ever lived . . . on land or in the sea

• Continued to grow throughout their lives––the older they got, the bigger they grew

• Grew to the length of an adult sperm whale, or possibly bigger

• Weighed more than 12 T. rex dinosaurs or 8 adult elephants

• A lower jaw nearly 10 feet long ( T. rex entire skull was only 3 1/2 feet)

• Possessed massive teeth up to 17.5 inches

• Jaws powerful enough to lift a truck and tear it in half––the most powerful bite force in history

• Swam with four, 10 ft paddle fins that spanned about 35 feet from fin tip to fin tip

• An ambush predator that would hide on the seabed and attack with lightning speed