A–ZAdd dino

Not a dinosaur — marine reptile

"Near to reptile"

Plesiosaurus

Early Jurassic · 201–194 MyaPiscivoreEngland

Not a dinosaur — a marine reptile so odd that when Mary Anning unearthed the first complete skeleton in 1823, the French anatomist Georges Cuvier suspected a fraud. A tiny head sits atop a neck longer than the rest of its body, built from roughly 40 vertebrae, propelled by four broad flippers like an underwater flight.

Length
3.5 m
Height
1 m
Weight
450 kg
Top speed
10 km/h

Field notes

  • Discovered by pioneering fossil hunter Mary Anning at Lyme Regis, England, in 1823.
  • Its neck alone contains around 40 vertebrae — more than almost any other animal.
  • It likely "flew" underwater, flapping its four flippers like a penguin rather than paddling.
Meet the rest of the Plesiosauridae family →