Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Carcharodontosauridae | Age | Geologic time | 115 - 105 Ma | | Cretaceous | |
Acrocanthosaurus atokensis | Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Saltasauridae | Age | Geologic time | 70 - 66 Ma | | Cretaceous | |
Alamosaurus sanjuanensisIt was a titanosaur, a group of dinosaur with towering neck that were among the largest animal ever lived on land. Its body was likely clad in bony spikes and thick armor to protect it from predators. |
Phylum | Class | Order | Family | Chordata | Reptilia | Pterosauria | Azhdarchidae | Age | Geologic time | 95 Ma | | Cretaceous | |
AlanqaAlanqa is a genus of pterosaur from the Late Cretaceous Kem Kem Beds (which date to the late Albian or Cenomanian age) of southeastern Morocco. | Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Allosauridae | Age | Geologic time | 150 - 145 Ma | | Jurassic | | Allosaurus |
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Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Diplodocoidae | Age | Geologic time | 130 - 125 Ma | | Cretaceous | |
Amargasaurus cazaui | Phylum | Class | Order | Family | Chordata | Mammalia | Artiodactyla | Ambulocetidae | Age | Geologic time | 47.8 - 41.3 Ma | | Paleogene | |
Ambulocetus natans |
Phylum | Class | Order | Family | Chordata | Mammalia | Carnivoria | Amphicyonidae | Age | Geologic time | 46.2 - 1.8 Ma | | Paleogene | Neogene | Quaternary | |
AmphicyonidaeAmphicyonids were big carnivorous mammals that inhabited North America, Europe, Asia and Africa for almost 45 million years. They are popularly known as "bear-dogs" because their anatomy resembled a mix of both animals, of which they were relatives. | Phylum | Class | Order | Family | Chordata | Mammalia | ? | ? | Age | Geologic time | 44 - 43 Ma | | Paleogene | |
Anatoliadelphys maasaeAnatoliadelphys was unlike any of its northern contemporaries, which are tiny, bug-eating critters. For one, it was big-weighting roughly as much as a honeydew melon, Anatoliadelphys was an order of magnitude more massive than any other northern metatherian mammal. It was also carnivorous, armed with burly jaws lined with rugged premolars, allowing for a powerful bite that could have splintered bone or crunched the shells of armored invertebrates. Based on analysis of Anatoliadelphys's skeleton, the cat-sized animal was probably an excellent climber and grasper, and would have been at home in the trees. In life, Anatoliadelphys would have resembled something akin to one of Australia's quolls crossed with a possum. However, instead of the lovely, wet-eyed pile of fluff staring out at you from a Qantas brochure, Anatoliadelphys would have been more like a mini marsupial tree-hyena, hungrily licking its bone-crushing chops while stalking prey in the canopy. |
Phylum | Class | Order | Family | Chordata | Mammalia | Artiodactyla | Triisodontidae | Age | Geologic time | 60 - 32 Ma | | Paleogene | | Andrewsarchus mongoliensis | Phylum | Class | Order | Family | Chordata | Reptilia | Ornithischia | Ankylosauridae | Age | Geologic time | 68 - 66 Ma | | Cretaceous | |
Ankylosaurus magniventrisAnkylosaurus is a genus of armored dinosaur. The largest known ankylosaurid, Ankylosaurus measured up to 6.25 m (20.5 feet) in length, 1.7 m (5.6 feet) in height, and weighed 6 tonnes (13,000 lb). It was a quadrupedal animal, with a broad, robust body. It had a wide, low skull, with two horns pointing backwards from the back of the head, and two horns below these that pointed backwards and down. The front part of the jaws were covered in a beak, with rows of small, leaf-shaped teeth further behind it. It was covered in armor plates, or osteoderms, with bony half-rings covering the neck, and had a large club on the end of its tail. Bones in the skull and other parts of the body were fused, increasing their strength, and this feature is the source of the genus name |
Phylum | Class | Order | Family | Chordata | Reptilia | Pterosauria | Anurognathidae | Age | Geologic time | 150.8 - 148.5 Ma | | Jurassic | |
Anurognathus ammoniAnurognathus is a small pterosaur known for its short head, massive eyes, and small teeth. Its large eyes suggest that it hunted during the dark in the forests of Jurassic Period Germany. | Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Diplodocidae | Age | Geologic time | 154 - 144 Ma | | Jurassic | | Apatosaurus lousiae |
Phylum | Class | Order | Family | Arthropoda | ? | ? | ? | Age | Geologic time | 443 - 419 Ma | | Silurian | |
Aquilonifer spinosusThis 430 million year old fossil animal was an arthropod related to crustaceans and insects. It had a unique way of caring for its young: they were attached to the body of the mother by thin tethers. This method of brood care has given Aquilonifer the nickname the kite runner. | Phylum | Class | Order | Family | Chordata | Mammalia | Carnivoria | Odobenidae | Age | Geologic time | 10 - 9.5 Ma | | Neogene | |
Archaeodobenus akamatsuiAbout 10 million years ago, a distant cousin of the modern walrus snapped at fish as it swam near the shore of what is now modern Japan, a new study finds. The roughly 10-foot-long (3 meters) creature didn't have tusks as walruses do today, but instead sported "moderate-sized upper canines," that measured 3.4 inches (86.3 millimeters) long, the researchers wrote in the study. It's no surprise this ancient pinniped (a group of fin-footed, semi-aquatic animals that includes seals, sea lions and walruses) didn't have tusks, researchers said. The walrus ancestor, which weighed a whopping 1,042 pounds (473 kilograms), looked more like a sea lion. |
Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Archaeopterygidae | Age | Geologic time | 150 Ma | | Jurassic | |
Archaeopteryx lithographica | Phylum | Class | Order | Family | Chordata | Mammalia | Artiodactyla | Entelodontidae | Age | Geologic time | 38 - 24.8 Ma | | Paleogene | |
ArchaeotheriumArchaeotherium is a member of Entelodontidae, popularly known as terminator pigs. Despite its boar-like appearance, this cow-sized predator was more closely related to the hippopotamus and whales. |
Phylum | Class | Order | Family | Chordata | Aves | Cathartiformes | Teratornithidae | Age | Geologic time | 7 - 5 Ma | | Neogene | | Argentavis magnificens | Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Antarctosauridae | Age | Geologic time | 112 - 93 Ma | | Cretaceous | | Argentinosaurus huinculensis |
Phylum | Class | Order | Family | Chordata | Reptilia | Ichthyosauria | Ophthalmosauridae | Age | Geologic time | | | Jurassic | |
ArthropterygiusArthropterygius is an extinct genus of ophthalmosaurid ichthyosaur which existed in Canada and Russia during the late Jurassic period. It contains the type species Arthropterygius chrisorum. Arthropterygius is the generic replacement name for Ophthalmosaurus chrisorum. A. chrisorum has several features that separate it from the genus Ophthalmosaurus, including a highly angled articulation between the radius and ulna and the humerus and a foramen for the internal carotid artery (a major artery that supplies blood to the brain) on the posterior surface of the basisphenoid. Maxwell 2010 found it to be the sister taxon of Caypullisaurus, an ophthalmosaurid from Argentina. However, many recent cladistic analyses found it to be the basalmost member of the Ophthalmosauridae. | Phylum | Class | Order | Family | Chordata | Reptilia | ? | Silesauridae | Age | Geologic time | 245 Ma | | Triassic | |
AsilisaurusAsilisaurus is an extinct genus of silesaurid archosaur. It is one of the oldest known animals on the dinosaur/pterosaur side of the archosaurian tree, dating to about 245 million years ago. Asilisaurus measured from 1 to 3 metres (3 to 10 ft) long and 0.5 to 1 metre (2 to 3 ft) high at the hip, and weighed 10 to 30 kilograms (20 to 70 lb). |
Phylum | Class | Order | Family | Chordata | Reptilia | Sauropsida | ? | Age | Geologic time | 240 Ma | | Triassic | |
Atopodentatus unicusWhen it was first described in 2014, this marine reptile was thought to have had a bizarre zipper-like mouth. Two new fossils discovered in 2016, however, proved that the first fossil was badly crushed and its face more closely resembled a handheld vacuum cleaner instead. | Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Titanosauridae | Age | Geologic time | 83.6 - 66 Ma | | Cretaceous | |
Austroposeidon magnificusAt about 25 m (85 ft) long, Austroposeidon is among the largest dinosaurs ever found in Brazil. It is named after the Greek god of earthquakes Poseidon, in reference to its sheer size. |
Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Dromaeosauridae | Age | Geologic time | 70 Ma | | Cretaceous | |
AustroraptorAustroraptor was one of the largest dromaeosaurid dinosaurs to have lived. It was a bipedal carnivore from the Cretaceous of Argentina. | Phylum | Class | Order | Family | Chordata | Reptilia | Saurischia | Avimimidae | Age | Geologic time | 70 Ma | | Cretaceous | |
Avimimus portentosusAvimimus was a genus of oviraptorosaurian theropod dinosaur, named for its bird-like characteristics, that lived in the late Cretaceous in what is now Mongolia, around 70 million years ago. |