Plateosaurus, the first of the giant dinosaurs.
— Allen, describing Plateosaurus
in Dawn of the Mesozoic

Plateosaurus (plat-ee-o-saw-us; meaning "Broad Reptile" or "Flat Reptile") was a large Prosauropod Dinosaur that lived in the Late Triassic period. This creature was an early ancestor of the Jurassic leviathans - the sauropods. It ate plants and was one of the first large dinosaurs to walk the earth.

It was the first and best known of the early giant herbivores. Probably travelling in herds, Plateosaurus was able to move on all fours and could also rear up into a bipedal posture. This animal was a peaceful plant eater that would travel in large herds across continents for food.



As the first giant dinosaurs, Plateosaurus lived during the Late Triassic Period from 225-208 million years ago.


Being the first of the giant dinosaurs, Plateosaurus was also a very large animal compared to the other types of animals it lived alongside. In fact, they were the largest herbivores of their time. Plateosaurus size was the key to their success and these vegetarians, ranging from 4.8 meters to an astonishing 11 meters in length and weighing at between 600 kg and 4 tonnes, four times the weight of a Saltwater crocodile (the largest reptile alive in the 21st century), Plateosaurus were simply to large to be threatened even by Liliensternus and Postosuchus.

Balanced on its long hind legs and reaching up with its long neck, Plateosaurus was able to feed on higher branches of conifers and ferns. It had distinctive hands with small fingers and a large clawed thumb. The hands had effective grasping ability and the claw was possibly used for ripping up roots or tearing at branches.

Plateosaurus is known from over one hundred partial to complete skeletons, including ten skulls. Plateosaurus is the most common and well known European Triassic vertebrate fossil from the late Triassic and was the largest land animal of the period.


Like many herbivores, Plateosaurus also lived and traveled in huge herds of up to 100 or more individuals. It is hard to believe that these four legged beasts are related to Coelophysis, but these were herbivorous dinosaurs. Rearing up, Plateosaurus was also able to use its long thumb claws for defense against predators such as Postosuchus.