This evidence , combined with the small size of other primitive relatives such as Microraptor and the troodontid Anchiornis , indicates that the common ancestor of dromaeosaurids , troodontids , and birds ( which is called the ancestral paravian ) may have been very small , at around 65 cm in length and 600 to 700 grams of mass .
This evidence , and Microraptor and the troodontid Anchiornis , suggests the common ancestor of dromaeosaurs , troodontids , and birds - the ` ancestral paravian ' - may have been very small , at around 65 cm in length and 600 to 700 grams of mass .