cellular - characterized by or divided into or containing cells or compartments (the smallest organizational or structural unit of an organism or organization); the cellular construction of a beehive; any effective opposition to a totalitarian regime must be secretive and cellular.
They are among the smallest of birds, most species measuring in the 7.5â13 cm (3â5 in) range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm bee hummingbird, weighing less than a U.S. penny (2.5 g). They are known as hummingbirds because of the humming sound created by their beating wings which flap at high frequencies audible to humans.
There are at least 35 species known to date. The smallest is Rahonavis (meaning death-from-the-clouds bird), which was about 2.5 feet long, and weighed around 15 pounds; the largest is Utahraptor, 23 feet in length and roughly 600 pounds. Velociraptor in particular got to about 6 feet in length and around 60 pounds.