Paleontologist Peter Mackovicky commented on the Manning team 's study , stating that small , primitive dromaeosaurids ( such as Microraptor ) were likely to have been tree-climbers , but that climbing did not explain why later , gigantic dromaeosaurids such as Achillobator retained highly curved claws when they were too large to have climbed trees .
Paleontologist Peter Mackovicky said that small , primitive dromaeosaurids ( such as Microraptor ) were likely to have been tree-climbers , but that climbing did not explain why later , gigantic dromaeosaurids such as Achillobator retained highly curved claws when they were too large to have climbed trees .