Etruscan ShrewAlso known as the pygmy shrew, it is considered the smallest mammal by mass. It measures around 3-5 centimeters in length.
Paedocypris progenetica This is the world's smallest fish, found in the swamps of Indonesia and measuring around 7-8 millimeters.
Brookesia micraThis species of chameleon from Madagascar is one of the smallest reptiles, with males measuring just over 2 centimeters in length.
Bee HummingbirdKnown as the world's smallest bird, this species can be found in Cuba and measures about 6 centimeters long.
FairyflyThese tiny wasps belong to the family Mymaridae and are among the smallest insects, measuring only around 0.2 to 1 millimeter.
Featherwing BeetleThese beetles, belonging to the family Ptiliidae, are some of the smallest insects. They measure around 0.5 to 1.2 millimeters in length.
Pygmy MarmosetAlso known as the pocket monkey, it is the world's smallest monkey species. They measure about 12 to 15 centimeters in length, excluding the tail.
Speckled Padloper Tortoise This is the world's smallest tortoise species, measuring around 6-8 centimeters in length.
Paedophryne amauensisThis species of frog, found in Papua New Guinea, holds the title for the world's smallest known vertebrate. It measures about 7-8 millimeters.
Dwarf LanternsharkThis species of shark is considered the smallest shark in the world. It measures about 17-20 centimeters in length.