Ground slothGround sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. Ground sloths varied widely in size, with the largest genera Megatherium and Eremotherium being around the size of elephants. Ground sloths are a paraphyletic group, as living tree sloths are thought to have evolved from ground sloth ancestors. The early evolution of ground sloths took place during the late Paleogene and Neogene of South America, while the continent was isolated.
Bone WarsThe Bone Wars, also known as the Great Dinosaur Rush, was a period of intense and ruthlessly competitive fossil hunting and discovery during the Gilded Age of American history, marked by a heated rivalry between Edward Drinker Cope (of the Academy of Natural Sciences of Philadelphia) and Othniel Charles Marsh (of the Peabody Museum of Natural History at Yale). Each of the two paleontologists used underhanded methods to try to outdo the other in the field, resorting to bribery, theft, and the destruction of bones.
ChasmosaurusChasmosaurus (ˌkæzmoʊˈsɔːrəs ) is a genus of ceratopsid dinosaur from the Late Cretaceous Period in North America. Its given name means 'opening lizard', referring to the large openings (fenestrae) in its frill (Greek chasma, meaning 'opening', 'hollow', or 'gulf'; and sauros, meaning 'lizard'). With a length of and a weight of —or anywhere from 2,200 to nearly 5,000 lbs., give or take—Chasmosaurus was of a slightly smaller to ‘average’ size, especially when compared to larger ceratopsians (such as Triceratops, which were about the size of an African bush elephant).
American lionPanthera atrox, better known as the American lion, also called the North American lion, or American cave lion, is an extinct pantherine cat. Panthera atrox lived in North America during the late Pleistocene epoch and the early Holocene epoch, from around 340,000 to 11,000 years ago. The species was initially described by American paleontologist Joseph Leidy in 1853 based on a fragmentary mandible (jawbone) from Mississippi; the name means "savage" or "cruel".
MegalonyxMegalonyx (Greek, "great-claw") is an extinct genus of ground sloths of the family Megalonychidae, native to North America. It evolved during the Pliocene Epoch and became extinct during the Quaternary extinction event at the end of the Pleistocene-Early Holocene, living from ~5 million to ~13,000 years ago. The type species, M. jeffersonii (also called Jefferson's ground sloth), the youngest and largest known species, measured about in length and weighed up to .
AnkylosaurusAnkylosaurus is a genus of armored dinosaur. Its fossils have been found in geological formations dating to the very end of the Cretaceous Period, about 68–66 million years ago, in western North America, making it among the last of the non-avian dinosaurs. It was named by Barnum Brown in 1908; it is monotypic, containing only A. magniventris. The generic name means "fused" or "bent lizard", and the specific name means "great belly". A handful of specimens have been excavated to date, but a complete skeleton has not been discovered.
AmphicoeliasAmphicoelias (ˌæmfᵻˈsiːliəs, meaning "biconcave", from the Greek ἀμφί, amphi: "on both sides", and κοῖλος, koilos: "hollow, concave") is a genus of herbivorous sauropod dinosaur that lived approximately 150 million years ago during the Tithonian (Late Jurassic Period) of what is now Colorado, United States. Amphicoelias was moderately sized at about in length and in body mass, shorter than its close relative Diplodocus. Its hindlimbs were very long and thin, and its forelimbs were proportionally longer than in relatives.
PachycephalosaurusPachycephalosaurus (ˌpækᵻˌsɛfələˈsɔːrəs meaning "thick-headed lizard", from Greek pachys-/παχύς- "thick", kephale/κεφαλή "head" and sauros/σαῦρος "lizard") is a genus of pachycephalosaurid ornithischian dinosaur. The type species, P. wyomingensis, is the only known species, but some researchers argue that the genus Stygimoloch might be a second species, P. spinifer or a juvenile specimen of P. wyomingensis. It lived during the Maastrichtian age of the Late Cretaceous period in what is now western North America.
African elephantAfrican elephants are members of the genus Loxodonta comprising two living elephant species, the African bush elephant (L. africana) and the smaller African forest elephant (L. cyclotis). Both are social herbivores with grey skin, but differ in the size and colour of their tusks and in the shape and size of their ears and skulls. Both species are considered at heavy risk of extinction on the IUCN Red List; as of 2021, the bush elephant is considered endangered and the forest elephant is considered critically endangered.
