The Deinonychosauria (meaning "fearsome claw lizards") were a successful clade of theropods that lived during the Late Jurassic and Cretaceous Periods. These carnivores are known for their switchblade-like second toes. The clade has been divided into two further clades — Dromaeosauridae and Troodontidae. Dromaeosauridae includes some of the most fearsome killers of the Cretaceous Period: Deinonychus, Velociraptor, and Utahraptor. The largest known of these was possibly Utahraptor, and Microraptor was among the smallest (40 cm or 16 in).