Extinct is a classification category on the International Union for the Conservation of Nature’s (IUCN) Threatened Species List.
Extinction occurs when a species — also called “taxon” for the list — no longer exists anywhere on earth. When scientists have done extensive research and agree that there is no longer a single individual specimen of the species they declare it extinct. Essentially, extinction represents the termination of a taxon.
In the history of our planet, scientists estimate that 4 billion species have populated it over time, but 99% of those are now extinct animals. Since 1500 alone, approximately 900 species have gone extinct. Among these extinct animals are the West African black rhinoceros, the baiji white dolphin, the Tasmanian tiger, the dodo, and Stellers sea cow.
There are six main reasons why species now become extinct:
- Habitat loss
- Introduction of a foreign species
- Loss of genetic variation
Human actions have played a huge role in species extinction in more recent history, but they’re not the only culprit. Of the 99 percent of species that have gone extinct on the planet, most of these extinct animals were victims of cataclysmic events or evolutionary problems. Typically, species have a lifespan of about 10 million years, but there are some that stick around for hundreds of millions. Take jellyfish; they have shimmied around the world’s oceans for about 550 million years! However, just because most animals eventually go extinct doesn’t mean we should not be concerned with their conservation status. When species are unnaturally dying out, to maintain the planet’s ecological balance, we must make an effort to ensure their survival.
The Albertonectes had the longest neck out of other Elasmosaurids.
Allosaurus is the official state fossil of Utah because of the abundant number of fossils found in the state.
Differnt Lizard” or Allosaurus weighed around two tonnes that is almost equal to a car.
Only one fossil has been found for this dinosaur and it was lost very soon after discovery.
Andrewsarchus is the largest terrestrial mammalian carnivore to have ever lived.
Although the Anteosaurus looked like a crocodile, it is more related to mammals than reptiles.
The Arambourgiania was not a dinosaur but instead a pterosaur!
Archaeoindris was the largest primate to evolve in Madagascar
The family Entelodontidae is commonly referred to as "hell pigs."
Archelons are the largest turtles to have ever lived in the world
The South American spectacled bear is its closest relative living today.
The first fossil from the genus Arctotherium was discovered back in 1852.
The Argentavis Magnificens was the heaviest flight bird to ever exist
The Argentinosaurus weighed as much as 10 elephants!
Arsinoitherium was a twin-horned mammal that looked like a rhino but is more closely related to present-day elephants.
Arthropleura was the largest terrestrial invertebrate to have ever lived
Extinct ancestor of all domesticated cattle!
Largest terrestrial predator of the Cenozoic era
If a barosaurus were alive today, it could stand on its hind legs and look in a 5th floor apartment window.
Barylambda was one of the largest animals that lived during the Paleocene
Palentologists originally believed that brachiosaurus lived in the water, but they lived on land.
Bull and Terriers were explicitly bred for bull-baiting, a savage blood sport where certain dog breeds would attack an angered bull tied to a pole.
Despite its large, muscular body, the Cape lion actually rests more than 20 hours a day
The Carolina parakeet is one of the few parrots that lived as far north as the United States
Cave bears may have been worshiped by primitive humans.
Unlike modern lions, cave lions didn't have a significant mane.
Cervalces latifrons are the largest species of deer that ever existed.
The Coryphodono looked like a fancy rhinocerous, but it was more related to elephants
Crocodylomorphs include extinct ancient species as well as 26 living species today.
This dinosaur was known as the elvissaur due to its pompadour-like crest.
Scientists don't know whether daedon had scales, feathers, fur, or something else.
Despite being bipedal, Deinocheirus had a large forearm
Deinosuchus was probably the biggest crocodilian that ever lived
Desmostylus has no living descendant.
Dilophosaurus was the largest predatory dinosaur in North America during the Early Jurassic Epoch of the Jurassic Period.
Dimetrodon was among the largest predators of the Early Permian Period.
Dinocrucuta had very strong jaws capable of crushing bones.
The only species currently recognized of this ancient baboon is Dinopithecus ingens.
Their long tales could have been used as a whip!
Diprotodon was the largest marsupial that ever lived.
Native to the island of Mauritius!
Deodicurus was one of the largest glyptodonts to have ever lived.
Dunkleosteus had a bite force strong enough to cut through pirey.
Elasmosaurus is an extinct reptile species.
Elasmotherium might have had a monstrous horn, giving it the name "The Siberian Unicorn."
Embolotherium had a ram on its snout like a rhino but they never used it as a weapon.
Epidexipteryx was one of the smallest non-avian dinosaurs to ever exist.
Equus giganteus is the largest species of horse that has ever lived.
Unlike modern amphibians, Eryops had a well-developed rib cage
Euplocephalus are the only Ankylosaurid dinosaurs with a bone plated head.
Eurypterus has a long tail that looks like a scorpion's stinger
Finches have strong, conical bills that help them break open tough seeds that many other birds cannot.
Gastornis had a massive beak, but they probably ate plants instead of flesh.
Some cryptozoologists think that Gigantopithecus survives to this day as "The Bigfoot."
Gorgosaurus probably lived and hunted in packs.
The Haast's eagle was the largest eagle to have ever existed.
Haikouichthys was the first animal to develop a well-defined head
The hainosaurus was named after the Hainaut province of Belgium where the first specimen was discovered.
The position of the Hallucigenia's head puzzled scientists for several years
Hatzegopteryx was one of the largest flying animals to have ever lived.
Helicoprion was one of the largest cartilaginous fish of all time.
Herrerasuarus was one of the earliest dinosaurs in fossil records
The eyes of Hippopotamus gorgops were positioned on eyestalks which allowed it to see above the water surface when submerged.
Unlike present-day pengiuns, Icadyptes lived in a warm habitat near the equator.
Gave birth to live young instead of laying eggs like other reptiles
Ichthyostega was one of the first aquatic animals to venture on land
The Irish elk had the biggest antlers of any known deer species.
Josephoartigasia monesi the largest known rodent
Calls could be heard up to a quarter mile away
Leedsichthys is one of the largest fish ever discovered
Liopleurodon were fast swimmers that lived entirely under water, but they had no gills
The Livyatan had 1 to 1.2 foot long, interlocking teeth
Lystrosaurus was one of the few terrestial species that survived the permian extinction
Machaeroides had large saber-teeth, much like the saber-toothed tiger.
The Macrauchenia was a large mammal, at nearly ten feet in length, weighing about 2,299 pounds.
Magyarosaurus is the smallest sauropod dinosaur to have ever lived
Maiasaura dinosaurs can grow to 31 feet long.
Masiakasaurus had dentition adapted to catching fast-moving prey.
Some people believe that Megalania still exists in remote areas, although those beliefs have never been validated with evidence.
Mageneura was the largest insect that has ever lived. However, it wasn't the heaviest
Megatherium probably used its lips more than its tongue when feeling for choice leaves in the treetops.
The Meiolania had a massive head that it was unable to put fully inside its shell.
The Mosasaurus was much longer than the fearsome Tyrannosaur rex.
Muttaburrasaurus is named after the town of Muttaburra in central Queensland.
Roamed Asia and Europe for around 100,000 years!
the Nuralagus is the biggest rabbit on record
Opabinia had five stalked eyes on its head.
Scientists once considered the Ornithocheirus an ancestor to modern birds
Ornithomimus translates from Greek to mean “bird mimic.”
Oviraptor means "egg thief" or "egg seizer," though they were quite protective of their own eggs.
The Pachycephalosaurus' head was up to 30 times thicker and stronger than a human skull.
Palaeloxodon namadicus was the largest land mammal ever found
This snake was as long as a school bus!
Scientists were able to determine that Paleoparadoxia was exclusively aquatic by comparing the rib cages of fossils to modern species of mammals like dugongs and polar bears.
Panthera atrox was about 25 percent larger than modern lions
The Parasaurolophus ran on its hindlegs at speeds of up to 30mph!
The patagotitan's bones were hollow and air-filled.
The biggest members of the Pelagornithidae family were the largest flying birds known.
It's a genus of terror birds
Plesiosaur had a short tail and an extremely long neck
Pliosaurs were the short-necked version of plesiosaurs.
Spiky Herbavore that looks like "bowser"
The largest variety of kangaroo to have ever been discovered.
These parrot-headed dinosaurs had beaks and feather-like quills on their tails!
The Psittacosaurus dinosaurs had four limbs but were mostly bipedal.
Pterodactyl is not technically a dinosaur. Although they lived during the same time as dinosaurs, they are classified as winged reptiles.
"The ribcage of a Puertosaurus was as large as a school classroom!"
Purussaurus had a bite force that is higher than that of any creature that has ever lived
The quagga is a subspecies of plains zebra.
Quetzalcoatlus northropi was one of the largest flying animals ever found
One of the biggest mammals of the dinosaur age that used to eat other dinosaurs
Rhamphosuchus had a narrow snout with a beak-like appearance.
Canines up to 7 inches long!
Some sandpipers can migrate more than 8,000 miles without stopping!
Sarcosuchus is a relative of present-day crocodiles.
Sarkastadon was one of the largest land mammal carnivores of all time!
Unlike most reptiles, Scutosaurus' legs were positioned underneath its body to support its great weigh
Although Seymouria had so many reptilian features, it was an amphibian
Shantungosaurus was one of the largest duck-billed dinosaurs to have ever lived.
Despite the massive size of the Shastasaurus, it only ate soft-bodied prey.
The modern Spectacled Bear, which lives in South America, is related to the Short-Faced Bear!
Simbakubwa kutokaafrika was as big as a polar bear.
Sinosauropteryx were prominent in the Cretaceous and Jurassic periods.
Sivatherium was a large giraffid and also one of the largest ruminants of all-time.
The biggest species in the Smilosuchus genus, S. gregorii, was the largest known reptile of its time, reaching a length of up to 39 feet.
The Spinosaurus is the biggest carnivorous dinosaur ever discovered!
Hunted to extinction in 17 years!
The largest freshwater turtle known to have ever lived!
It walked on two legs and leaned forward
Tarbosaurus‘ name “bataar” is a mispelling of the Mongolian word “baatar,” which means “hero.”
The Tasmanian tiger could open its mouth almost 90 degrees.
The length of the Thalassomedon's neck was up to half its body length
Thanatosdrakon was one of the largest pterosaurs that lived in South America.
Some theropods had feathers and may have been ancestors of modern birds.
Scientists have speculated that its bite force was equivalent to that of a 551 pound lion!
Thylacoleo carnifex was the largest carnivorous mammal in Australia
Thylacosmilus resembled saber-toothed cats, but they’re not related
The Titanoboa was a massive, 42-foot-long boa constrictor that lives 58-60 million years ago.
Troodon formosus means "wounding tooth" in Greek, a name that describes its serrated teeth.
Tully Monsters can neither be classified as vertebrates nor invertebrates due to their ambiguous body structure.
Tusoteuthis was one of the largest cephalopods ever
Tylosaurus was a marine reptile that is closely related to modern-day snakes and monitor lizards.
They had many air pockets in their skeleton which kept them light despite their tremendous size.
The Uintatherium was an exceptionally large and exceptionally ugly ungulate that lived during the Eocene epoch
Vegavis was one of the earliest birds to have a sound-producing organ
The albatross is related to the waimanu!
The body of Wiwaxia was covered by rows of sclerites and spines
The woolly rhinoceros roamed the earth between three and a half million and 14,000 years ago.
Smal eel-like ancient shark
The Xenoceratops is the oldest known horned dinosaur ever discovered in Canada.
They may have acted as 'gardeners' to clear vegetation and disperse seeds through their feces.
Xenotarsosaurus was one of the first fossils discovered in South America's Bajo Barreal formation.
Xiaosaurus was a small and lightweight dinosaur
Xiaotingia used its feathery hindlimbs for short-distance flights
List of Extinct Animals
Conservation Status Lists
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