Albertosaurus is a genus of large tyrannosaurid theropod dinosaur that lived in northwestern North America during the early to middle Maastrichtian age of the Late Cretaceous period, about 71 million years ago. The type species, A. sarcophagus, was apparently restricted in range to the modern-day Canadian province of Alberta, after which the genus is named, although an indeterminate species has been discovered in the Corral de Enmedio and Packard Formations of Mexico. Scientists disagree on the content of the genus and some recognize Gorgosaurus libratus as a second species.
Camarasaurus was a genus of quadrupedal, herbivorous dinosaurs and is the most common North American sauropod fossil. Its fossil remains have been found in the Morrison Formation, dating to the Late Jurassic epoch, between 155 and 145 million years ago.
Dryptosaurus is a genus of eutyrannosaurian theropod dinosaur that lived on the island continent of Appalachia approximately 67.6 million years ago during the end of the Maastrichtian age of the Late Cretaceous period. Dryptosaurus was a large, bipedal, ground-dwelling carnivore that could grow up to 7.5 metres (25 ft) long and weigh up to 756–1,500 kilograms (1,667–3,307 lb). Although it is now largely unknown outside of academic circles, the famous 1897 painting of the genus by Charles R. Knight made Dryptosaurus one of the more widely known dinosaurs of its time, in spite of its poor fossil record. First described by Edward Drinker Cope in 1866 and later renamed by Othniel Charles Marsh in 1877, Dryptosaurus is among the first theropod dinosaurs ever known to science.
Zapsalis is a genus of dromaeosaurine theropod dinosaurs. It is a tooth taxon, often considered dubious because of the fragmentary nature of the fossils, which include teeth but no other remains.
Cedarosaurus was a nasal-crested macronarian dinosaur genus from the Early Cretaceous Period (Valanginian). It was a sauropod which lived in what is now Utah. The fossils were discovered in 1996 in eastern Utah within the rocks of the Yellow Cat Member of the Cedar Mountain Formation. It was officially named and described by Tidwell, Carpenter and Brooks in 1999.
Marshosaurus is a genus of medium-sized carnivorous theropod dinosaur, belonging to the family Piatnitzkysauridae, from the Late Jurassic Morrison Formation of Utah and possibly Colorado.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1989.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1994.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1980.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1903.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1904.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1906.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1907.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1941.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1933.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1939.
Amphicoelias is a genus of herbivorous sauropod dinosaur that lived approximately 150 million years ago during the Tithonian of what is now Colorado, United States. Amphicoelias was moderately sized at about 18 metres (59 ft) in length and 15 metric tons 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.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1878.
A substantial amount of paleontological research has occurred within or conducted by people from the United States. Paleontologists have found that at the start of the Paleozoic era, what is now "North" America was actually in the southern hemisphere. Marine life flourished in the country's many seas. Later the seas were largely replaced by swamps, home to amphibians and early reptiles. When the continents had assembled into Pangaea drier conditions prevailed. The evolutionary precursors to mammals dominated the country until a mass extinction event ended their reign.
This timeline of tyrannosaur research is a chronological listing of events in the history of paleontology focused on the tyrannosaurs, a group of predatory theropod dinosaurs that began as small, long-armed bird-like creatures with elaborate cranial ornamentation but achieved apex predator status during the Late Cretaceous as their arms shrank and body size expanded. Although formally trained scientists did not begin to study tyrannosaur fossils until the mid-19th century, these remains may have been discovered by Native Americans and interpreted through a mythological lens. The Montana Crow tradition about thunder birds with two claws on their feet may have been inspired by isolated tyrannosaurid forelimbs found locally. Other legends possibly inspired by tyrannosaur remains include Cheyenne stories about a mythical creature called the Ahke, and Delaware stories about smoking the bones of ancient monsters to have wishes granted.
