What is Stellaraptor?

The Stellaraptor a very rare raptor in the age of the dinosaurs they hunted on their own it is very rare to find one witch was not destroyed by velociraptors which hunted them to extinction in just a few years the one full skull found was so hard that the only reason they were able to keep it is they hit it on top of the skull with a hammer and it didn't even crack witch means it had a very hard practically unbreakable skull fastest raptor of them all believed to run 60mph playfully and over 120mph hunting and being hunted had no feathers from study but could be incorrect.