Forget the lizards from Jurassic Park: a new fossil found in Germany suggests that all dinosaurs were feathered.
It has a bushy tail like a squirrel, but according to a new study it is the oldest feathered carnivorous dinosaur discovered ever. Not only, according to researchers, the Upper Jurassic fossil found in Germany could wipe out the idea we have of dinosaurs as "big lizards" forever.
The fossil of 150 millions years ago, recently unearthed in a limestone quarry in Bavaria and "superbly preserved", was baptized Sciurumimus albersdoerferi ("Scirius" is the name of the genus the squirrels belong to).
Sciurumimus probably was a young Megalosaurus, a group of large bipedal carnivorous dinosaurs. The small found specimen had a big head, short forelimbs and long hair-like feathers that covered the body, the back and the tail.
"When I first saw it I was left speechless. Even without considering the exceptional state of plumage, it is one of the finest fossils discovered ever," says the Research Manager Oliver Rauhut, paleontologist at the State Collection of Paleontology and Geology of Bavaria, Germany.
lizards
goodbye?
Until now, paleontologists found presence of feathers just on celurosauri (Coelurosauria), a group of theropod dinosaurs which includes birds similar to the subgroups of tirannosauroidi and of ornitomimosauri maniraptora.
Since Sciurumimus belongs to a completely different evolutionary branch despite of celurosauri, the fossil suggests that the presence of feathers in dinosaurs was not an exception but the norm, says Rauhut.
"It is likely that all dinosaurs were feathered," adds the researcher. "I think we should put aside the idea of dinosaurs as overgrown lizards."
Moreover, although the fossils of feathered dinosaurs are relatively scarce (the conditions for the fossilization of feathers are extremely rare), the fact that they have been discovered in various parts of the world seems to indicate that this feature was quite widespread during the Cretaceous and upper Jurassic. This is what Corwin Sullivan emphasizes, a paleontologist at the Chinese Academy of Sciences in Beijing.
The most interesting aspect, according to Sullivan, is what Sciurumimus represents for the evolution of feathers. Until now, scholars believed that feathers had evolved in celurosauri. Sciurumimus anyway, is the first "clear evidence" that the plumage appeared long before those dinosaur-like birds, says Sullivan.
According to the authors of the study, this suggests that the feathered dinosaurs had a common ancestor who transmitted this feature in every branch of the evolutionary tree of dinosaurs. It is also possible, anyway, despite the plumage appears similar in all the groups of dinosaurs, this trait has independently evolved.
"We have to find more fossils, even less similar to birds than Sciurumimus is, to understand how things went."
The study on new fossil species is published in the journal Proceedings of the National Academy of Sciences.
(on www.antikitera.net)
