April 4, 2022 Scott Kraus

Plateosaurus is a Late Triassic Dinosaur

Plateosaurus, pronounced PLAT-ee-oh-SAW-rus, was a sauropodomorph which lived around 204 to 214 million years ago during the Late Triassic period. It was discovered in 1834 by Johann Friedrich Engelhardt when paleontology was still a new science, in fact, the first known use of the word “paleontology” was not until a few years later. Consequently, confusion prevailed for many years regarding the information for the dinosaur. For instance, numerous type species were described that were eventually found to be invalid names or junior synonyms. But, fortunately, now it is one of the most well understood dinosaurs. We have benefited from over 100 skeleton specimens of Plateosaurus having been recovered, some are almost complete.

Quick Facts

What did the Plateosaurus look like?

This large, late Triassic dinosaur may have had a superficial resemblance to carnivorous theropods, like Tyrannosaurus. But there was no need to fear this gentle giant, which was a herbivore and fed only on plants.  The plateosaurus was tall, and could use its height to eat higher flowering plants and fruit.  Easily adaptable to its environment, adult sizes could vary greatly, and is believed to have corresponded to the availability of food sources.  Plateosaurus walked on two legs and used its short, but powerful forelimbs, for foraging and possibly defense.

Physical Attributes of Plateosaurus

The Plateosaurus was a tall, lean, leaf eating machine. It had a small skull and a long, flexible neck. Its hind limbs were very strong as were its arms, but the latter were short and unsuitable for walking on, as a bipedal. On its hands were large claws that may have been used for feeding and defensive purposes. There used to be widespread confusion about the identity of Plateosaurus and there was a lot of disagreement about how it looked, but luckily it is now one of the best understood dinosaurs.

There have been a large number of finds that provide today’s scientists with an unprecedented look at how these animals lived.   For instance, previous models of reconstructed skeletons often portrayed the Plateosaurus on all fours, as a quadruped animal.  This model is now know to be incorrect.  The creature was in fact a bipedal animal, and therefore walked on two legs all the time.  The eye sockets were set on opposite sides of the skull, allowing the Plateosaurus good all-round vision to spot predators.  It was also adapted with bird-like lungs, and the unusually large volume of air it contained help the Plateosaurus look larger than it really was.

What did Plateosaurus eat?

From the shape of the tooth crown, which is similar to modern day herbivorous or omnivorous iguanas, we can be sure that Plateosaurus were one or the other. The diet of the Plateosaurus consisted mostly of plants and fruits.  The Plateosaurus came equipped with teeth that were excellent for chewing and grinding plants, but scientist Paul Barrett suggested that prosauropods supplemented their plant diets with carrion and small prey. Plateosaurus was also thought to be cathemeral, which means they were active (such as with feeding) during the day and night, possibly while trying to avoid the hottest part of the day.

Plateosaurus had a growth pattern that was similar to the other non-avian dinosaurs that scientists have studied to date. Their growth rate and final mature adult size varied, probably due to environmental factors like the availability of food sources. Some Plateosaurus reached their full size at 16 feet in length, while others were fully grown at 33 feet. Evidence of rapid growth in the bone structures of Plateosaurus also suggests it may have been capable of thermoregulation, which is how well an animal can keep its body temperature within certain boundaries, and endothermy, or the colloquial “warm blooded”.

How did Plateosaurus move?

The locomotion of Plateosaurus was for awhile unknown. Theories abounded about the way that Plateosaurus moved. At one point, it was thought to be able to move quadruped-ally. At another point, it was proposed that it could hop like a kangaroo, albeit a clumsy one. (Needless to say that idea was ridiculed by at least one other scientist) Yet another theory suggested that it might have been able to alternate between walking biped-ally and quadruped-ally. The bipedal and quadrupedal was consensus for awhile, until a study of the forelimbs of Plateosaurus by the scientists Bonnan and Senter was conducted in 2007. The study showed that Plateosaurus wasn’t able to pronate its hands, which would have been required for quadrupedal walking. Therefore, they concluded that Plateosaurus was bipedal and only moved along the ground on it’s hind limbs. Scientists also believe that Plateosaurus could run fast as evidenced by its proportionally long lower hind limbs and metatarsus.

Discovery and History of Plateosaurus

The Plateosaurus was discovered in 1834, and named “Englehardti” in reference to the scientist who found the first fossils, Johann Freidrich     Englehardt.  Most skeletal finds have been located in Germany, but there are also some important discoveries that have occurred in Switzerland and Austria as well.  More than 100 different skeletons of this creature have been discovered, but all in Europe.  The location and number of Plateosaurus finds have been the subject of some debate.  Scientists were interested to know why the Plateosaurus was found the way it was. Finds indicate that the dinosaur deaths all happened to occur at the same location, of all the same type of dinosaur, and with no juvenile members present at all.  Of the many theories meant to explain theses curiosities, the one that has the most credence is the mud pit theory.  The story goes like this: Plateosaurus, traveling in herds, or attracted as a herd to available water sources, soon trampled the watering hole into a swampy mire.  The bigger heavier animals got stuck in the deep mud, and were trapped.  Lighter, younger members of Plateosaurus could escape the mud, and hence no juvenile remains.  Scientists also found loose theropod teeth around the finds, indicating that lighter weight scavengers had been able to eat their fill, while still not getting trapped by the mud.

Historical Significance of Plateosaurus

As an early type of sauropodomorph during the Triassic period, Plateosaurus was one of the earliest dinosaur species. It was also one of the first dinosaurs to be discovered in the history of modern paleontology. As such, the attempts by scientists to understand Plateosaurus in the approximately 180 years we have known about it have not always gone smoothly. Fortunately we understand Plateosaurus much better today than we did in the beginning. The history of our knowledge of Plateosaurus is almost as much of an indication about how far paleontology itself has come as it is an education in the development of dinosaurs.