Donnosaurus

Donnosaurus is an extinct species of Hadrosaur that lived in Siberia and northern Europe during the Late Pliocene and Late Pleistocene. It is descended from the same ancestors as the eastern duckbill and the southern duckbill, but has followed the different path, with its crest being fattened and widened until it resembles a front-pointed version of that of a mesozoic Corythosaurus. It was well suited to life in the freezing temperatures and did really well in the tundra. They were part of the megafauna that was important to the ecosystem, feeding on the would-be uncontrolable weeds (plant pests) that lived in its native range. They were about as smart as an elephant, as their brain cases and DNA samples shows, so they'd be able to know where to go when disaster strikes. Early humans (Homo Sapiens) are most likely to have caused the extinction of Donnosaurus during the last Ice Age. However, the species was brought back by extracting its DNA and using the eastern duckbill as a surrogate mother, although it is not a complete Donnosaurus, it may be a complete Donnosaurus one day and people are planning to reintroduce Donnosaurus back to its former range to help control the spread of plants it fed on again.