Information: - Haramiyidans seem to be the earliest known herbivores amongst basal mammals. Their teeth, which are by far the most common remains, resemble those of the multituberculates. However, based on "Haramiyavia", the jaw is less derived; and at the level of evolution of earlier basal mammals like "Morganucodon" and "Kuehneotherium", with a groove for ear ossicles on the dentary. They are the longest lived mammalian clade of all time. However, a more recent study, in November 2015, may dispute this and suggested the Haramiyida were not mammals after all, but were part of a more ancestral side branch instead. - Plesiosaurus (Greek: ""/"plesios", near to + ""/"sauros", lizard) is a genus of extinct, large marine sauropterygian reptile that lived during the early part of the Jurassic Period, and is known by nearly complete skeletons from the Lias of England. Although there are a number of modern-day myths surrounding this order of creature, such as the myth of the Loch Ness Monster, these creatures are known to be extinct. It is distinguishable by its small head, long and slender neck, broad turtle-like body, a short tail, and two pairs of large, elongated paddles. It lends its name to the order Plesiosauria, of which it is an early, but fairly typical member. It contains only one species, Plesiosaurus dolichodeirus. "P. brachypterygius", "P. guilielmiiperatoris", and "P. tournemirensis" were assigned to new genera, "Hydrorion", "Seeleyosaurus" and "Occitanosaurus". - Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct taxon of rodent-like mammals that existed for approximately one hundred and sixty-six million years, the longest fossil history of any mammal lineage, but eventually declined from the late Palaeocene onwards, disappearing in the early Oligocene, though they might have lived even longer into the Miocene, if gondwanatheres are part of this group. More than 200 species are known, ranging from mouse-sized to beaver-sized. These species occupied a diversity of ecological niches, ranging from burrow-dwelling to squirrel-like arborealism to jerboa-like hoppers. Multituberculates are usually placed outside either of the two main groups of living mammalsTheria, including placentals and marsupials, and Monotrematabut closer to Theria than to monotremes. - Pterodactylus (, from the Greek , "pterodaktulos," meaning "winged finger") is an extinct flying reptile genus of pterosaurs, whose members are popularly known as pterodactyls. It is currently thought to contain only a single species, Pterodactylus antiquus, the first pterosaur species to be named and identified as a flying reptile. - Kuehneotherium is an early mammaliaform genus that lived during the late Triassic period and is characterized by reversed-triangle pattern of molar cusps. Although a large number of fossils have been found, the fossils are limited to teeth, dental fragments, and mandible fragments. The genus includes "Kuehneotherium praecursoris" and all related species. It was first named and described by Doris M. Kermack, K. A. Kermack, and Frances Mussett in November 1967. The family Kuehneotheriidae and the genus "Kuehneotherium" were created to house the single species "Kuehneotherium praecursoris". Modeling based upon a comparison of the "Kuehneotherium" jaw with other mammals indicates they were about the size of a modern day shrew between 4 and 5.5 g at adulthood. - Allotheria ( meaning '' other beasts '' , from the Greek , allos - other and , therion - wild animal ) is an extinct branch of successful Mesozoic mammals . The most important characteristic was the presence of lower molariform teeth equipped with two longitudinal rows of cusps . Allotheria includes Multituberculata , Gondwanatheria ( which may be part of Multituberculata , the sister group to Cimolodonta ) , and probably Haramiyida , though some studies show them to not even be mammals and differing from true allotheres significantly . Allotheres also had a narrow pelvis , indicating that they gave birth to tiny helpless young like marsupials do . - Rodents (from Latin "rodere", "to gnaw") are mammals of the order Rodentia, which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents; they are found in vast numbers on all continents except Antarctica. They are the most diversified mammalian order and live in a variety of terrestrial habitats, including human-made environments. - The Mesozoic Era (or ) is an interval of geological time from about . It is also called the Age of Reptiles, a phrase introduced by the 19th century paleontologist Gideon Mantell who viewed it as dominated by diapsids such as "Iguanodon", "Megalosaurus", "Plesiosaurus" and "Pterodactylus". This Era is also called from a paleobotanist view the Age of Conifers. - The beaver (genus Castor) is a large, primarily nocturnal, semiaquatic rodent. "Castor" includes two extant species, the North American beaver ("Castor canadensis") (native to North America) and Eurasian beaver ("Castor fiber") (Eurasia). Beavers are known for building dams, canals, and lodges (homes). They are the second-largest rodent in the world (after the capybara). Their colonies create one or more dams to provide still, deep water to protect against predators, and to float food and building material. The North American beaver population was once more than 60 million, but as of 1988 was 612 million. This population decline is the result of extensive hunting for fur, for glands used as medicine and perfume, and because the beavers' harvesting of trees and flooding of waterways may interfere with other land uses. - Plagiaulacida is a group of extinct multituberculate mammals. Multituberculates were among the most common mammals of the Mesozoic, "the age of the dinosaurs". Plagiaulacids, an informal suborder, are the most basal of this order, and ranged from the Middle Jurassic Period to the Lower Cretaceous Period of the northern hemisphere. - Theriiformes is a subclass of mammals. The term was coined in 1997 by McKenna & Bell in their classification of mammals. - Theria (Greek: "", wild beast) is a subclass of mammals amongst the Theriiformes (the sister taxa to Yinotheria). Theria includes the eutherians (including the placental mammals) and the metatherians (including the marsupials). - Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia and the Americas. A distinctive characteristic common to these species is that most of the young are carried in a pouch. Well-known marsupials include kangaroos, wallabies, koalas, possums, opossums, wombats, Tasmanian devils, and the recently extinct thylacines. Others include the numbat, the bandicoot, the bettong, the bilby, the quoll, and the quokka. - Cimolodon is a genus of mammal from the Upper Cretaceous of North America. It was a member of the extinct order of Multituberculata within the suborder Cimolodonta and possibly the family Cimolodontidae. - Gondwanatheria is an extinct group of mammals that lived during the Upper Cretaceous through the Miocene in the Southern Hemisphere, including Antarctica. They are known only from isolated teeth, a few lower jaws, two partial skulls and one complete cranium. Because of this fragmentary knowledge their placement is not clear. - A mouse (plural: mice) is a small rodent characteristically having a pointed snout, small rounded ears, a body-length scaly tail and a high breeding rate. The best known mouse species is the common house mouse ("Mus musculus"). It is also a popular pet. In some places, certain kinds of field mice are locally common. They are known to invade homes for food and shelter. - In biology, a taxon (plural taxa; back-formation from "taxonomy") is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is not uncommon, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. - The Cimolodonta are a taxon of extinct mammals that lived from the Cretaceous to the Eocene. They were some of the more derived members of the extinct order Multituberculata. They probably lived something of a rodent-like existence until their ecological niche was assumed by true rodents. The more basal multituberculates are found in a different suborder, "Plagiaulacida". - The Eocene Epoch, lasting from , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope C in the atmosphere was exceptionally low in comparison with the more common isotope C. The end is set at a major extinction event called the "Grande Coupure" (the "Great Break" in continuity) or the EoceneOligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of the epoch are well identified, though their exact dates are slightly uncertain. - Morganucodon ("Glamorgan tooth") is an early mammaliaform genus that lived during the late Triassic period. It first appeared about 205 million years ago. Unlike many other early mammals, "Morganucodon" is well represented by abundant and well preserved, though in the vast majority of cases disarticulated, material. Most of this comes from Glamorgan in Wales ("Morganucodon watsoni"), but fossils have also been found in Yunnan Province in China ("Morganucodon oehleri") and various parts of Europe and North America. Some at least closely related animals ("Megazostrodon") are known from exquisite fossils from South Africa. - In ecology, a niche is a term with a variety of meanings related to the behavior of a species living under specific environmental conditions. The ecological niche describes how an organism or population responds to the distribution of resources and competitors (for example, by growing when resources are abundant, and when predators, parasites and pathogens are scarce) and how it in turn alters those same factors (for example, limiting access to resources by other organisms, acting as a food source for predators and a consumer of prey). "The type and number of variables comprising the dimensions of an environmental niche vary from one species to another [and] the relative importance of particular environmental variables for a species may vary according to the geographic and biotic contexts". - Megalosaurus (meaning "Great Lizard", from Greek , "megas", meaning 'big', 'tall' or 'great' and , "sauros", meaning 'lizard') is a genus of large meat-eating theropod dinosaurs of the Middle Jurassic period (Bathonian stage, 166 million years ago) of Southern England. Although fossils from other areas have been assigned to the genus, the only certain remains of "Megalosaurus" come from the late Middle Jurassic of the Oxfordshire. - Mammals are any vertebrates within the class Mammalia (from Latin "mamma" "breast"), a clade of endothermic amniotes distinguished from reptiles and birds by the possession of a neocortex (a region of the brain), hair, three middle ear bones and mammary glands. The sister group of mammals may be the extinct "Haldanodon." The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade. The mammals consist of the Yinotheria including monotrema and the Theriiformes including the theria. - Iguanodon (; meaning "iguana-tooth") is a genus of ornithopod dinosaur that existed roughly halfway between the first of the swift bipedal hypsilophodontids of the mid-Jurassic and the duck-billed dinosaurs of the late Cretaceous. While many species have been classified in the genus "Iguanodon", dating from the late Jurassic Period to the late Cretaceous Period of Asia, Europe, and North America, research in the first decade of the 21st century suggests that there is only one well-substantiated species: "I. bernissartensis", which lived from the late Barremian to the earliest Aptian ages (Early Cretaceous) in Belgium and possibly elsewhere in Europe, between about 126 and 125million years ago. "Iguanodon" were large, bulky herbivores. Distinctive features include large thumb spikes, which were possibly used for defense against predators, combined with long prehensile fifth fingers able to forage for food. - The jerboa (from "") forms the bulk of the membership of the family Dipodidae. Jerboas are hopping desert rodents found throughout Northern Africa and Asia east to northern China and Manchuria. They tend to live in hot deserts. What entity does 'allotheria' has the relation 'taxon rank' with?
The answer to this question is:
subclass