Dromaeosauridae
Dromaeosaurs were small to medium-sized dinosaurs, ranging from about 0.7 meters in length (2.3 ft, in the case of Mahakala) to over 6m (20 ft, in Utahraptor and Achillobator). Some were larger: undescribed specimens of Utahraptor in the BYU collections may have been up to  long. Large size appears to have evolved at least twice among dromaeosaurs. A possible third lineage of giant dromaeosaurs is shown by isolated teeth on the Isle of Wight, England. The teeth belong to a Utahraptor-sized animal but are more similar in shape to the teeth of velociraptorines.