This prehistoric animal called attention to the paleontologist who discovered it to see how their upper limbs were in proportion smaller than others of the same gender: their short forearms depart from the condition characteristic of all long arms and their relatives dromaeosaurids avian nearby. This would therefore be a missing link between dinosaurs and modern birds.
Perhaps (and this is my opinion) is an example of regression, this means that they resumed their oldest species characteristics. As is the case of flightless birds also reduce its wings.
Instead, it was her hind legs which facilitated the classification of this new species, the family Dromaeosauridae or "corridors lizards." By this I mean that was a fast runner Austroraptor, who had strong back legs and he used to hunt their prey.