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Classification and Evolution of Owls

A Great Horned Owl in a Barn

Classification of owls

Owls belong to the phylogenetic class Aves. There are 2 distinct families of owls. One is the family of Barn Owls, and the other consists of all other types of owls. The 17 known species of Barn Owls throughout the world belong to the family Tytonidae, and the other 161 known species of owls belong to the family Strigidae.

Evolution of owls

The oldest known owl fossils are from the Miocene, which occurred 38-54 million years ago. Based on the fossil evidence, these ancient owls evolved into the 2 families of modern owls. The oldest Barn Owl fossils found thus far are estimated to be at least 24 million years old. Fossil evidence indicates that giant Barn Owls once thrived in the Caribbean and Mediterranean regions between 10,000 and 30,000 years ago. These giants, known as Ornimegalonyx, were 2 to 3 times as large as modern Barn Owls and twice the size of modern Great Horned Owls. Ornimegalonyx is thought to have preyed upon animals such as the giant sloth and giant rodents such as the capybara, which are over 4 feet long. There are 134 known species of owls in the world, with the Eurasian Eagle Owl being the largest and the Elf Owl being the smallest. Although owls share many of the same characteristics, there are some notable differences in behavior between species. Two-thirds of the species of owls are nocturnal and the remaining third are diurnal.

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