An article published in the journal “Cretaceous Research” describes the analysis of the fossilized remains of a skeleton of Ornithomimus (photo ©Eduard Solà), a dinosaur that lived in the late Cretaceous period, between 99.6 and 65.5 million years ago. This is the best example of this kind of dinosaurs found so far because the conservation of its feathers and skin is more extensive compared to the specimens previously found. Aaron van der Reest, the main author of the study, discovered these fossils in 2009 in the Dinosaur Provincial Park in Alberta, Canada.

The Ornithomimus is a genus of dinosaur belonging to the family of ornithomimosaurs (Ornithomimosauria) which is classified into two species: Ornithomimus velox and Ornithomimus edmontonicus. Starting in 1995, fossils were discovered that showed that Ornithomimus the conservation of part of their feathers showing similarities with today’s ostriches. The name Ornithomimus in fact means bird mimic.

Now the analysis of the Ornithomimus specimen discovered in 2009 allowed Aaron van der Reest, along with Alexander Wolfe and Philip Currie to see the details of this dinosaur’s plumage. The feathers are totally crushed due to the sediment compaction but scanning electronic microscoppy revealed their three-dimensional keratin structure on its tail and body.

This speciman is providing new information about the Ornithomimus’ appearance but also on other characteristics, such as how it kept its body temperature and the phases of the evolution of feathers. This genus of dinosaur had a height between 4 and 5.5 meters (between about 13 and 18 feet) and as a result much larger that today’s birds and yet there are many similarities with birds and in particular with the ostriches.

since the early ’90s many feathered dinosaurs have been found mainly in China. Archaeopteryx has been known since the 19th century but the discovery of many new species of dinosaurs with various characteristics typical of birds confirmed more and more their relation. The fact that feathered dinosaurs such as Ornithomimus lived in North America proves that they were widespread. The reconstruction of the family tree leading from feathered dinosaurs to birds is complex and research such as the one about the Ornithomimus help to clarify it.