The Psittacosaurus (or ‘parrot lizard’ in English) is a dinosaur that dates from the Early Cretaceous Period which was about 130 – 100 million years ago. It was found in what is now known as Asia, and is the dinosaur genus with the most member species. There are actually 9 – 11 species that are formally recognised from fossils that have been found throughout different parts of modern day Asia, such as China, Russia, Mongolia, and even possibly as far south as Thailand.
The Paleontologist and the former President of the American Museum of Natural History, Henry Fairfield Osborn, first named and published his findings on the dinosaur on October 19, 1923. All of the Psittacosaurus species were bipedal herbivores which were gazelle-sized. Physical characteristics include a high and powerful beak on its upper jaw. One species (or more) had long feather like structions on its tail and lower back which may have been used for display.
Although this genus is species rich, the Psittacosaurus is not as famous to the general public as its distant relative, the Triceratops. It is a shame, as this is one of the most completely known dinosaur genera known to humankind. Over 400 individual fossils have been collected thus far, including many complete skeletons. Many different age classes are represented through these specimens ranging from this dinosaur as a hatchling until as an adult.
The many species of Psittacosaurus varied in size of its skeleton and skull. However, they maintained the same overall body shape. The most well known species is the Psittacosaurus mongoliensis which reached up to 2 metres tall. The maximum body weight for an adult would have been over 20 kilograms for this species. On the other hand, the smallest known species is the Psittacosaurus ordosensis which was at least smaller compared to the Psittacosaurus mongoliensis by 30%.
There are 17 species that have been thought to be part of the genus Psittacosaurus. However, only between 9 to 11 of these are considered as valid species today. This is actually the highest number of valid species that is assigned to any single non-avian dinosaur. The earliest known species of this dinosaur is the Psittacosaurus lujiatunensis, which was found in the lowest beds of the Yixian Formation.