Information: - Chalk is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite. Calcite is an ionic salt called calcium carbonate or CaCO. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells (coccoliths) shed from micro-organisms called coccolithophores. Flint (a type of chert unique to chalk) is very common as bands parallel to the bedding or as nodules embedded in chalk. It is probably derived from sponge spicules or other siliceous organisms as water is expelled upwards during compaction. Flint is often deposited around larger fossils such as Echinoidea which may be silicified (i.e. replaced molecule by molecule by flint). - Caenagnathoidea ( '' recent jaw forms '' ) is a group of advanced oviraptorosaurian dinosaurs from the Cretaceous Period of what are now Asia and North America . They are distinct for their characteristically short , beaked , parrot - like skulls , often with bony crests atop the head . They ranged in size from Caudipteryx , which was the size of a turkey , to the 8 meter long , 1.4 ton Gigantoraptor . The group ( along with all maniraptoran dinosaurs ) is close to the ancestry of birds . The most complete specimens have been found in Asia , representing members of the sub-group Oviraptorinae . Notable but fragmentary remains are also known from North America , almost all of which belong to the subgroup Elmisaurinae . The earliest definitive caenangnathoid is Microvenator celer , which dates to the late Aptian age of the early Cretaceous period , though the slightly earlier Caudipteryx from the lower Yixian Formation of China , may also be a member of this group . - Eurasia is the combined continental landmass of Europe and Asia. The term is a portmanteau of its constituent continents. Located primarily in the Northern and Eastern Hemispheres, it is bordered by the Atlantic Ocean to the west, the Pacific Ocean to the east, the Arctic Ocean to the north, and by Africa, the Mediterranean Sea, and the Indian Ocean to the south. The division between Europe and Asia as two different continents is a historical and cultural construct, with no clear physical separation between them; thus, in some parts of the world, Eurasia is recognized as the largest of five or six continents. In geology, Eurasia is often considered as a single rigid megablock. However, the rigidity of Eurasia is debated based on the paleomagnet data. - Dinosaurs are a diverse group of animals of the clade Dinosauria that first appeared during the Triassic. Although the exact origin and timing of the evolution of dinosaurs is the subject of active research, the current scientific consensus places their origin between 231 and 243 million years ago. They became the dominant terrestrial vertebrates after the TriassicJurassic extinction event 201 million years ago. Their dominance continued through the Jurassic and Cretaceous periods and ended when the CretaceousPaleogene extinction event led to the extinction of most dinosaur groups 66 million years ago. - A genus (genera) is a taxonomic rank used in the biological classification of living and fossil organisms in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. - The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 1.0 Ma to 113.0 1.0 Ma (million years ago), approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous. - The Ornithomimosauria, ornithomimosaurs ("bird-mimic lizards") or ostrich dinosaurs are theropod dinosaurs which bore a superficial resemblance to modern ostriches. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period of Laurasia (now Asia, Europe and North America), as well as Africa and possibly Australia. The group first appeared in the Early Cretaceous and persisted until the Late Cretaceous. Primitive members of the group include "Nqwebasaurus", "Pelecanimimus", "Shenzhousaurus", "Hexing" and "Deinocheirus", the arms of which reached 2.4m (8feet) in length. More advanced species, members of the family Ornithomimidae, include "Gallimimus", "Struthiomimus", and "Ornithomimus". Some paleontologists, like Paul Sereno, consider the enigmatic alvarezsaurids to be close relatives of the ornithomimosaurs and place them together in the superfamily Ornithomimoidea (see classification below). - The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic Period million years ago (Mya) to the beginning of the Paleogene Period Mya. It is the last period of the Mesozoic Era. The Cretaceous Period is usually abbreviated K, for its German translation "Kreide" (chalk). - Feathers are epidermal growths that form the distinctive outer covering, or plumage, on birds. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They are among the characteristics that distinguish the extant birds from other living groups. - Birds (Aves), also known as avian dinosaurs, are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. They rank as the class of tetrapods with the most living species, at approximately ten thousand, with more than half of these being passerines, sometimes known as perching birds or, less accurately, as songbirds. - The Paleogene (or ; also spelled Palaeogene or Palogene; informally Lower Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago (Mya) to the beginning of the Neogene Period Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon. The Paleogene is most notable for being the time during which mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of the CretaceousPaleogene extinction event that ended the preceding Cretaceous Period. - Caudipteryx (which means "tail feather") is a genus of peacock-sized theropod dinosaurs that lived in the Aptian age of the early Cretaceous Period (about 124.6 million years ago). They were feathered and remarkably birdlike in their overall appearance. Two species have been described; "C. zoui" (the type species), in 1998, and "C. dongi", in 2000. - Maniraptora is a clade of coelurosaurian dinosaurs that includes the birds and the non-avian dinosaurs that were more closely related to them than to "Ornithomimus velox". It contains the major subgroups Avialae, Deinonychosauria, Oviraptorosauria and Therizinosauria. "Ornitholestes" and the Alvarezsauroidea are also often included. Together with the next closest sister group, the Ornithomimosauria, Maniraptora comprises the more inclusive clade Maniraptoriformes. Maniraptorans first appear in the fossil record during the Jurassic Period (see "Eshanosaurus"), and are regarded as surviving today as living birds. - Asia is Earth's largest and most populous continent, located primarily in the eastern and northern hemispheres and sharing the continental landmass of Eurasia with the continent of Europe. Asia covers an area of , about 30% of Earth's total land area and 8.7% of the Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Asia is notable for not only its overall large size and population, but also dense and large settlements as well as vast barely populated regions within the continent of 4.4 billion people. - Gigantoraptor is a genus of giant oviraptorosaurian theropod dinosaur. - In biology, a species (abbreviated sp., with the plural form species abbreviated spp.) is the basic unit of biological classification and a taxonomic rank. A species is often defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is often problematic. For example, in a species complex, the boundaries between closely related species become unclear or disappear altogether. Other ways of defining species include similarity of DNA, morphology, or ecological niche. The presence of locally adaptive traits may further subdivide species into infraspecific taxa such as subspecies. - Oviraptorosaurs ("egg thief lizards") are a group of feathered maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like skulls, with or without bony crests atop the head. They ranged in size from "Caudipteryx", which was the size of a turkey, to the 8 metre long, 1.4 ton "Gigantoraptor". The group (along with all maniraptoran dinosaurs) is close to the ancestry of birds. Analyses like those of Maryanska "et al" (2002) and Osmolska "et al." (2004) suggest that they may represent primitive flightless birds. The most complete oviraptorosaur specimens have been found in Asia. The North American oviraptorosaur record is sparse. 'caenagnathoidea' is related to which object entity through the relation of 'taxon rank'? Choices: - division - family - form - genus - group - series - species - subdivision - superfamily
Answer:
superfamily