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Vertebrate

This undated photo provided by Penn State University Prof. Blair Hedges shows a Caribbean gecko, Sphaerodactylus ariasae, one of the two smallest reptile species known to exist, curled up on a dime. Found in the Dominican Republic, the gecko is about 16 mm, and is also the smallest amniote vertebrate of 25,000 species (includes birds, mammals, and reptiles). Hedges described "I found it with a colleague, while crawling on my hands and knees among dead leaves, anticipating a small lizard, but that not that small!" He said. (AP Photo/Penn State University, Blair Hedges)

Tiny animals

A look at some of our planet’s smallest creatures.