Plateosaurus: Triassic Herbivore

Plateosaurus was the largest dinosaur known from the Triassic fossil record, although it was tiny compared to its descendants in the Jurassic Period. Fossils of this dinosaur have been very common in Europe, especially in Germany, France, and Switzerland. The abundance of fossils have led many scientists to believe that plateosaurus traveled in herds-an adaptation seen in both future large dinosaur and mammalian herbivores.

Plateosaurus seems to have set the stage for the largest herbivorous dinosaurs of all time: the sauropods. It also seems as though plateosaurus was one of the first dinosaurs to feed exclusively on plants rather than supplementing its diet with meat. Although it was not a direct ancestor of sauropods, it belonged to a related group of dinosaurs called prosauropods. This Triassic plant eater actually resembled a sauropod in a number of respects. It had a longer, stockier neck than some early predatory dinosaurs and its tail was broad in order to balance its large weight of up to three quarters of a ton. Its hind legs were longer than its front legs, but it seems as though plateosaurus walked about on all fours while occasionally rising to two in order to defend itself or feed on high branches. Overall, plateosaurus was about 25 to 30 feet long, which was very large compared to any herbivorous or carnivorous dinosaur of the Triassic. Eventually, as dinosaurs like this got bigger and bigger, they would sacrifice bipedal movement altogether in order to support their large bodies with columnar limbs. As herbivores got bigger, so did carnivores, so in effect plateosaurus initiated a sort of arms race among dinosaurs between predator and prey.

Plateosaurus was a herbivore, feeding on low-hanging trees, shrubs, or ferns. Its ability to rear up on its hind legs probably contributed to its success in reaching levels of vegetation that were as yet untouched by any dinosaur up to that point. Also, it sported four "fingers" on its forelimbs which would have helped plateosaurus to grasp and pull down stubborn vegetation toward its mouth. Its teeth were leaf-shaped and adapted for tearing and shearing tough plants. Specialized teeth for grinding vegetation would not evolve until later in the Mesozoic Era, so it seems likely that plateosaurus would have made use of stomach stones called gastroliths in order to aid digestion. In terms of defense, this gentle plant-eater had very little. It could have possibly run away from danger, but would probably have relied most on its sheer size in order to deter predators from attacking it in the first place.

As the forests increased in size during the warm, wet Jurassic Period, the plant-eating dinosaurs would undergo an explosion of evolution and reach the largest size of any beast ever to walk the planet.