World's tiniest vertebrate is a frog

The world's smallest vertebrate - animals that have a backbone - is a frog that could sit within the confines of your fingernail, a new study reports.

Scientists found the new species, which on average is just 7.7 millimeters long, in the southwestern Pacific island nation of Papua New Guinea.

The frog, scientifically named Paedophryne amauensis, spends its life in moist leaf litter on the floors of tropical wet-forests. Males call out with a continuous series of high-pitched notes at dawn and dusk, resembling the sound of crickets.

Typically, small frogs dry out quickly, but this tiniest species has a habitat that stays moist for most of the year. 

Researchers say the animals have simplified skeletons and are born directly as frogs, as opposed to first going through a tadpole stage. Researchers believe these creatures eat even smaller animals, such as mites.

Previously the smallest vertebrate was believed to have been a fish known as Paedocypris progenetica, which matures at 7.9 millimeters. There has been speculation that aquatic habitats are home to the world's smallest and largest vertebrates, but this frog contradicts that theory.

Original article here.