Acari

Description

Acari are a taxon of the Arachnida class and are the most abundant as well as the most diverse of the arachnids that include animals such as mites and ticks. The existence of these creatures has been dated as far back as 400 million years ago to the early Devonian Period, making them the oldest terrestrial animals. The species of Acari are relatively small in size being as small as the human follicle mite at around 0.1 mm and as large as ticks or the Red Velvet mite which can be as large as 10 mm. [ 1 ]

References

1. Walter, David Evans; Krantz, Gerald; Lindquist, Evert (December 13, 1996) "Acari. The Mites. Tree of Life Web Project.