The Pygmy Marmoset or Dwarf Monkey is one of the smallest primates and ties with the Slender Loris for smallest monkey. The Dwarf Monkey averages 14 to 16 cm in length (15 to 20 cm including its tail) and weighs 4.2 to 4.9 oz. Native to the rainforest canopies of Brazil, Columbia, Ecuador, Peru, and Bolivia, the Dwarf Monkey often snacks on gummy tree sap.
Two transparent spiny lobster post-larvae pose on the tips of fingers. A new computer simulation reveals how the tiny nippers travel in their first five months to a year of life, before they mature into adults. Read more
Smaller than a penny, two newly discovered frog species are considered the smallest ever found. The pipsqueaks live in Papua New Guinea and run about 0.4 inches (8-to-9 millimeters) in length. Read more on the tiny frogs
The Sphaerodactylus macrolepis (shown) and the Sphaerodactylus sputator are the two known species of the Dwarf Gecko. Both are found on Saint Martin and are the smallest reptiles in the world. Unlike the rest of the gekkoninae subfamily, Dwarf Geckos have round eyes, rather than vertical, and a round pad or scale at the end of each digit.
The Red and Grey Slender Lorises, or Loris tardigradus and Loris lydekkerianus, are the two smallest species of monkey. Both are native to the tropical rainforests of Southern India and Sri Lanka. The average loris grows to chipmunk size, at 15 to 25 cm and 10.5 to 12 oz. Pictured here is a baby Grey Slender Loris.
Thumbelina, a five-year-old Dwarf Miniature Horse, slides underneath the pasture fencing at Goose Creek Farms in St. Louis, MO, in 2006. At 17.5 inches, she was the smallest living horse in the world, and holds the record for the smallest horse in history.
This wallaby is a member of the Dorcopsulus genus and the world's tiniest known kangaroo. It was discovered by Kristofer Helgen of the Smithsonian Institution.
While the Irukandji Jellyfish may be tiny, it is extremely venomous. Native to Australia's marine waters, this jellyfish averages one cubic centimeter, yet its sting is so potent, coastal Australians have been known to suffer from "Irukandji symptoms."
Shown here is a young Rhinoderma darwinii frog, known in Spanish as Sapito de Darwin or Darwin's Frog. Found exclusively in Chilean forest streams, the Darwin's Frog is an endangered species measuring 2.5 to 3.5 cm -- pretty small, but not the smallest frogs out there.
The Stout Infantfish or Schindleria brevipinguis is a marine fish native to Australia's Great Barrier Reef and the Osprey Reef (in the Coral Sea off Australia's northeast coast). The Stout Infantfish, averaging 7 to 8.4 mm, is the second smallest fish and vertebrate behind the Paedocypris, a member of the carp family.
The Parasitic Wasp is often used in agricultural pest control by paralyzing and eventually killing its prey. Its genome is also used in pharmaceutical research.
The Bog Turtle or Glyptemys muhlenbergii is the smallest turtle in North America. Measuring 10 cm long and 3.9 oz, it is semi-aquatic and fancies hibernation and the mud. Despite its rather sedentary lifestyle, the Bog Turtle is a hot commodity in the black market pet trade for its miniature size.
Amy Twentyman of the Taronga Zoo, pushes a Little Penguin into the sea. The zoo, located at North Curl Curl Beach in Sydney, released two adult Little Penguins at the time of this photo (March 2009). The Little Penguins received care at Taronga's Wildlife Hospital.
Einstein, born in April 2010, may have laid claim to the world record for lightest foal. The Pinto Stallion weighed just 6 pounds and measured 14 inches in height when he was born in Barnstead, NH. Einstein's proportions match those of a human baby. Guinness has stated it will only consider claims from horses at least 4 years old.
Hummingbirds are among the smallest of birds measuring typically in the 3-5 in range. They can hover in mid-air by rapidly flapping their wings 12–90 times per second (depending on the species). They can also fly backwards, and are the only group of birds able to do so.
Pictured is the tiny Costa's Hummingbird, its most distinguishing feature being its vibrant purple cap and throat with the throat feathers flaring out and back behind its head.
Madame Berthe's mouse lemur (Microcebus berthae) or Berthe's mouse lemur is the smallest of the mouse lemurs and the smallest primate in the world; the average body length is 3.6 in.
Barbados Threadsnake (Leptotyphlops carlae) is a species of blind threadsnake. It is the smallest snake species currently known to exist.
The snake was first described and identified as a separate species in 2008 by S. Blair Hedges, a biologist from Pennsylvania State University. Hedges named the new species of snake in honor of his wife, Carla Ann Hass, a herpetologist who was part of the discovery team.
The Philippine Tarsier (Tarsius syrichta or Carlito syrichta), known locally as the Maumag in Cebuano/Visayan and Mamag in Luzon, is an endangered species of tarsier endemic to the Philippines and is one of the smallest primates, measuring as little as 3 and a half inches.
Denise's Pygmy Seahorse (Hippocampus denise) is a species of fish in the Syngnathidae family. They can be found in Pacific coral reefs off southern Japan and northern Australia. The pygmy seahorse is undoubtedly one of the most well camouflaged species in the oceans -- aided by its miniscule 5/8 inch size.
The Pink Fairy Armadillo (Chlamyphorus truncatus) or Pichiciego is the smallest species (3.5-4.5 inches) of armadillo -- mammals mostly known for having a bony armor shell. It is found in central Argentina where it inhabits dry grasslands and sandy plains with thorn bushes and cacti.
At just over 3/8 inches long, the Monte Iberia Eleuth (Eleutherodactylus iberia) is the smallest living frog in the northern hemisphere. It is the second-smallest frog (and tetrapod) in the world, following the Brazilian Gold Frog.
It was first discovered in 1996 on Mount Iberia, from which the animal gets its name, and exists in only two small regions of Cuba. Much remains unknown about this small creature.
You thought your teacup-sized Bichon Frise was small? Get a load of what nature has been up to while you were busy grooming. Just don't blink or you'll miss these tiny beasts.