Psittacosaurus

Period: Early cretaceous - 100 milion years ago
Where: United States (Wyoming), China, Mongolia, Canada (Alberta), South Siberia
Fossil dimension: 1,5 meters long
Quick facts: Psittacosaurus is one of the most completely known dinosaur genera, fossils of hundreds of individuals have been collected so far, including many complete skeletons. Most age classes are represented, from hatchling through to adult, which has allowed several detailed studies of Psittacosaurus growth rates and reproductive biology. The abundance of this dinosaur in the fossil record nas led to the labelling of lower cretaceous sediments of east Asia the Psittacosaurus biochron.