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Iaceornis Marshi
''Iaceornis'' is a genus of marine ornithuran dinosaurs closely related to modern birds. It was endemic to North America during the Late Cretaceous, living about 83.5 million years ago. It is known from a single fossil specimen found in Gove County, Kansas, and consisting of a partial skeleton lacking a skull. Since it was first discovered by Othniel Charles Marsh in 1877, the specimen (YPM 1734) was long considered to belong to the contemporary species ''Apatornis celer''. Because it is relatively complete, most discussions of ''Apatornis'' actually focused on the ''Iaceornis'' fossil. In 2004, paleontologist Julia A. Clarke showed that the skeleton actually differed in important characteristics of the wing bones from the true, holotype specimen of ''Apatornis''. Therefore, she assigned the more complete remains to a new genus and species, ''Iaceornis marshi'', meaning "Marsh's neglected bird".Clarke, J.A. (2004). "Morphology, phylogenetic taxonomy, and systematics of ''Ichthyor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julia Clarke
Julia Allison Clarke is an American paleontologist and evolutionary biologist who studies the evolution of birds and the dinosaurs most closely related to living birds. She is the John A. Wilson Professor in Vertebrate Paleontology in the Jackson School of Geosciences and a Howard Hughes Medical Institute Professor at the University of Texas at Austin. Education Clarke graduated with a B.A. in Comparative Literature and Geobiology from Brown University in 1995. She went on to study at Yale University, earning a Ph.D. from the Department of Geology and Geophysics in 2002. Career In 2005, Clarke led a research team that reexamined a fossil discovered within the rocks of Vega Island in the Antarctic in 1992. Computer tomography (CT) scans allowed for a more detailed analysis of the partial skeleton than had been possible earlier. It was determined to be ''Vegavis iaai,'' an extinct Antarctic bird and early relative of ducks and geese and thought to be the only species of modern b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. Phylogeneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithuran
Ornithurae (meaning "bird tails" in Greek) is a natural group that includes modern birds and their very close relatives such as the ichthyornithines and the hesperornithines. This clade is defined in the ''PhyloCode'' by Juan Benito and colleagues in 2022 as "the smallest clade containing '' Ichthyornis dispar'', ''Hesperornis regalis'', and '' Vultur gryphus''". Classification Ernst Haeckel coined the name in 1866 and included in the group all "true birds" with the "characteristic tail morphology of all extant birds" (translation by Jacques Gauthier). This distinguishes the group from ''Archaeopteryx'', which Haeckel placed in another new group called Sauriurae. Said simply, modern birds have short, fused pygostyle tails, while ''Archaeopteryx'' retained the long tail characteristic of non-avian theropod dinosaurs.Haeckel, Ernst (1866). ''Generelle Morphologie der Organismen''. Berlin: Georg Reimer. Gauthier converted Ornithurae into a clade, giving it a branch-based definit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutionary history, evolution of dinosaurs is a subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, Evolution of birds, having evolved from earlier Theropoda, theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomy (biology), taxonomic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the south and west by the Pacific Ocean. The region includes Middle America (Americas), Middle America (comprising the Caribbean, Central America, and Mexico) and Northern America. North America covers an area of about , representing approximately 16.5% of Earth's land area and 4.8% of its total surface area. It is the third-largest continent by size after Asia and Africa, and the list of continents and continental subregions by population, fourth-largest continent by population after Asia, Africa, and Europe. , North America's population was estimated as over 592 million people in list of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gove County, Kansas
Gove County is a county in the U.S. state of Kansas. Its county seat is Gove City, and its most populous city is Quinter. As of the 2020 census, the county population was 2,718. The county was named for Granville Gove, a captain of Company G of the 11th Kansas Cavalry Regiment Volunteer Cavalry, who died from battle wounds during the American Civil War. History Early history Eighty million years ago, Gove County was part of an ancient inland sea known as the Western Interior Seaway. Many students still visit the Castle Rock Badlands today to explore fossils. For many millennia, the Great Plains of North America were inhabited by nomadic Native Americans. From the 16th to the 18th centuries, the Kingdom of France claimed ownership of large parts of North America. In 1762, after the French and Indian War, France secretly ceded New France to Spain, per the Treaty of Fontainebleau. 19th century In 1802, Spain returned most of the land to France, but kept the title to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Othniel Charles Marsh
Othniel Charles Marsh (October 29, 1831 – March 18, 1899) was an American professor of paleontology. A prolific fossil collector, Marsh was one of the preeminent paleontologists of the nineteenth century. Among his legacies are the discovery or description of dozens of new species—including the stegosaurus and triceratops—and theories on the origins of birds. He spent his academic career at Yale College and was president of the National Academy of Sciences. Born into a modest family, Marsh was able to afford higher education thanks to the generosity of his wealthy uncle George Peabody. After graduating from Yale College in 1860 he traveled the world, studying anatomy, mineralogy and geology. He obtained a teaching position at Yale upon his return. From the 1870s to 1890s, he competed with rival paleontologist Edward Drinker Cope in a period of frenzied Western American expeditions known as the Bone Wars. Marsh's greatest legacy is the collection of Mesozoic reptiles, Creta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apatornis Celer
''Apatornis'' is a genus of ornithuran dinosaurs endemic to North America during the late Cretaceous. It currently contains a single species, ''Apatornis celer'', which lived around the Santonian-Campanian boundary, dated to about 83.5 million years ago. The remains of this species were found in the Smoky Hill Chalk of the Niobrara Formation in Kansas, United States. It is known from a single fossil specimen: a ''synsacrum'', the fused series of vertebrae over the hips. While the known fossil remains are very incomplete, enough has been found to reasonably estimate that the body length was between . The type specimen of ''A. celer'', YPM 1451, was reportedly discovered by Othniel Charles Marsh in October 1872 at Butte Creek in Logan County, Kansas. This location is now recognized as falling between Marker Units 15 and 19 of the Smoky Hill Chalk geological formation. An additional, more complete specimen had also been referred to ''Apatornis celer'' by Marsh.O. C. Marsh. 1873. On ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holotype
A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several examples, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN, the definitions of types are similar in intent but not identical in terminology or underlying concept. For example, the holotype for the butterfly '' Plebejus idas longinus'' is a preserved specimen of that subspecies, held by the Museum of Comparative Zoology at Harvard University. In botany and mycology, an isotype is a duplicate of the holotype, generally pieces from the same individual plant or samples from the same genetic individual. A holotype is not necessarily "ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and morphology. The results are a phylogenetic tree—a diagram depicting the hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in question. In addition to their use for inferring phylogenetic pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyornis
''Ichthyornis'' (meaning "fish bird", after its fish-like vertebrae) is an extinct genus of toothy seabird-like ornithuran from the late Cretaceous period of North America. Its fossil remains are known from the chalks of Alberta, Alabama, Kansas ( Greenhorn Limestone), New Mexico, Saskatchewan, and Texas, in strata that were laid down in the Western Interior Seaway during the Turonian through Campanian ages, about 95–83.5 million years ago. ''Ichthyornis'' is a common component of the Niobrara Formation fauna, and numerous specimens have been found. ''Ichthyornis'' has been historically important in shedding light on bird evolution. It was the first known prehistoric bird relative preserved with teeth, and Charles Darwin noted its significance during the early years of the theory of evolution. ''Ichthyornis'' remains important today as it is one of the few Mesozoic era ornithurans known from more than a few specimens. Description of the Ichthyornis It is thought that '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
