The smallest animals living on Earth can be determined on the basis of various aspects such as length, height, weight, genome size, and more. Although microscopic organisms like viruses are some of the smallest living entities on Earth, in our article we will discuss the smallest vertebrate species on Earth as determined by their body length. Here is a list of the smallest vertebrate species of various kinds living on Earth:
13. The Smallest Amphibian In The World
The smallest amphibian in the world, the Paedophryne amauensis, is also the world’s smallest vertebrate species. The animal is a frog that lives in Papua New Guinea. It was only recently discovered in August 2009, and described formally in 2012. The frog is only an average of 7.7 mm in length.
12. The Smallest Fish In The World
A cyprinid fish species, the Paedocypris progenetica, is endemic to Sumatra in Indonesia. Here, it is found in blackwater streams and peat swamps. The females of this species attain a maximum size of 10.3 mm while males grow up to 9.8 mm. It was also regarded as the world's smallest vertebrate species before the discovery of the frog Paedophryne amauensis in 2012.
11. The Smallest Lizard In The World
Two species of gecko, the Virgin Islands dwarf sphaero (S. parthenopion) and the dwarf gecko (Sphaerodactylus ariasae) are the smallest lizards as well as smallest reptiles in the world. These lizards are about 16 mm in length. There are also a few Brookesia chameleons found in Madagascar that are about the same length as the aforementioned geckos.
10. The Smallest Tortoise In The World
The speckled padloper tortoise (Homopus signatus), a tortoise species from South Africa and southern Namibia, is the world’s smallest species of tortoise. The males of this species measure around 6 to 8 cm while females are about 10 cm long.
9. The Smallest Crocodilian In The World
The Cuvier's dwarf caiman (Paleosuchus palpebrosus) is a small crocodilian species that is native to northern and central South America. Within its range, the crocodile inhabits the flooded forests, riverine forests, and other habitats near fast-flowing water bodies. It is able to tolerate cold better than other crocodilians. It reaches up to 1.6 meters in length.
8. The Smallest Snake In The World
The Barbados threadsnake (Leptotyphlops carlae) is a blind threadsnake that is endemic to the Caribbean island of Barbados. It is the tiniest snake in the world with a length of about 10 cm. The snakes are described to be "about as wide as a spaghetti noodle.” Termites and ant larvae comprise their primary diet.
7. The Smallest Bird In The World
The bee hummingbird (Mellisuga helenae) is believed to be the smallest bird in the world. It is also the smallest warm-blooded vertebrate living today. The bee hummingbird is endemic to the entire archipelago of Cuba. It is so small and light that it is claimed that the bird is lighter than the US or Canadian penny. It weighs about 1.8 g and is about 5 cm long. It is often mistaken for a bee, hence the name. The bird is known to drink water 8 times its total body mass and eat half its total body mass.
6. The Smallest Mammal In The World
The Kitti's hog-nosed bat or the bumblebee bat (Craseonycteris thonglongyai) is a vulnerable species of bat that lives in southeast Burma and western Thailand where it can be seen in limestone caves along rivers. The bat is not only the smallest bat species but also the world’s smallest mammal. The bat attains a length of about 3 to 4 cm and weighs around 1.5 to 2 g.
5. The Smallest Rodent In The World
The Baluchistan pygmy jerboa (Salpingotulus michaelis), also named as the dwarf three-toed jerboa, is the smallest rodent species in the world. The adults of this species average only 4.4 cm in length and weigh around 3.75 g. The species is considered to be endemic to Pakistan and is listed as the smallest rodent in the world in the 2010 Guinness Book of World Records where it shares this title with the African pygmy mouse.
4. The Smallest Cetacean In The World
The vaquita (Phocoena sinus) is not just the smallest cetacean in the world but also the rarest one. This critically endangered species of porpoise in on the brink of extinction with fewer than 30 individuals surviving as of November 2016. The highly restricted range of the species (endemic to the Gulf of California’s northern end) makes the vaquita population extremely vulnerable to several threats. The females of this species are usually larger than the males. Females on maturity attain an average length of about 140.6 cm while males grow up to about 134.9 cm. The flippers of this species are proportionately bigger and the fin is taller while the skull is smaller and the rostrum is shorter than the other porpoise species.
3. The Smallest Carnivoran In The World
The order Carnivora includes over 280 species of placental mammals referred to as carnivorans. Although carnivorans are all carnivore species, the world carnivore applies to any meat- eating organism which also might not be a carnivoran. The smallest of the carnivorans is the least weasel (Mustela nivalis). The animal is native to Eurasia, North Africa, and North America, and has also been introduced elsewhere in the world. The species is as small as about 11 cm in length and can weigh as little as 25 g.
2. The Smallest Marsupial In The World
Also known as the Ingram's planigale, the long-tailed planigale (Planigale ingrami), is the smallest marsupial species in the world. The creature inhabits the flooded grasslands, soiled woodlands, and blacksoil plains of the Top End of Australia. The planigale has a body length averaging between 110 to 130 mm and weighs around 4.3 g. The organism also has a unique head shape. Their head is more flattened than deep, and is just 3 to 4 mm from top to bottom. This shape of the head allows the creature to easily burrow into the tiniest cracks in the soil in search of prey or to hide from predators.
1. The Smallest Primate In The World
The smallest of the mouse lemurs, the Madame Berthe's mouse lemur (Microcebus berthae) is the world’s smallest living primate species. The lemurs live in western Madagascar’s Kirindy Forest. The species is named after Berthe Rakotosamimanana, a leading primatologist and conservationist based in Madagascar. The Berthe's mouse lemur has an average body length of only 9.2 cm and weighs around 30g.